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Definitions of Managed Objects for the DS1, E1, DS2, and E2 Interface Types
draft-ietf-atommib-rfc2495bis-06

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 3895.
Author Orly Nicklass
Last updated 2015-10-14 (Latest revision 2004-01-13)
RFC stream Internet Engineering Task Force (IETF)
Intended RFC status Proposed Standard
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IESG IESG state Became RFC 3895 (Proposed Standard)
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Responsible AD Bert Wijnen
Send notices to <orly_n@rad.com>, <faye@pedestalnetworks.com>
draft-ietf-atommib-rfc2495bis-06
INTERNET-DRAFT             DS1/E1/DS2/E2 MIB                January 2004

                     Definitions of Managed Objects
              for the DS1, E1, DS2 and E2 Interface Types

                   Sun January  11 11:52:36 EDT 2004

                  draft-ietf-atommib-rfc2495bis-06.txt

                         Orly Nicklass (editor)
                     RAD Data Communications, Ltd.
                             Orly_n@rad.com

                          Status of this Memo

   This document is an Internet-Draft and is in full conformance with
   all provisions of Section 10 of RFC2026. Internet-Drafts are working
   documents of the Internet Engineering Task Force (IETF), its areas,
   and its working groups.  Note that other groups may also distribute
   working documents as Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet- Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt.

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it describes objects used for managing DS1, E1, DS2
   and E2 interfaces.  This document is a companion to the documents
   that define Managed Objects for the DS0, DS3/E3 and Synchronous

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   Optical Network/Synchronous Digital Hierarchy (SONET/SDH) Interface
   Types.

   This document obsoletes RFC 2495.

1.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).
   Objects in the MIB are defined using the mechanisms defined in the
   Structure of Management Information (SMI).  This memo specifies a MIB
   module that is compliant to the SMIv2, which is described in STD 58,
   RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58, RFC 2580
   [RFC2580].

1.1.  Changes from RFC2495

   The changes from RFC2495 are the following:

        (1) The dsx1FracIfIndex SYNTAX matches the description range.

        (2) A value was added to dsx1TransmitClockSource.

        (3) Values were added to dsx1LineType.

        (4) Two objects were added, dsx1LineMode and dsx1LineBuildOut
            to better express transceiver mode and LineBuildOut for T1.

        (5) Reference was added to Circuit Identifier object.

        (6) Align the DESCRIPTION clauses of few statistic objects with
            the near end definition, the far end definition and with
            RFC3593.

        (7) Changes in Compliance Statements to include new objects.

        (8) A typographical error in dsx2E2 was fixed, new name is dsx1E2.

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1.2.  Changes from RFC1406

   The changes from RFC1406 are the following:

        (1)  The Fractional Table has been deprecated.

        (2)  This document uses SMIv2.

        (3)  Usage is given for ifTable and ifXTable.

        (4)  Example usage of ifStackTable is included.

        (5)  dsx1IfIndex has been deprecated.

        (6)  Support for DS2 and E2 have been added.

        (7)  Additional lineTypes for DS2, E2, and unframed E1
             were added.

        (8)  The definition of valid intervals has been clarified
             for the case where the agent proxied for other devices.  In
             particular, the treatment of missing intervals has been
             clarified.

        (9)  An inward loopback has been added.

        (10) Additional lineStatus bits have been added for Near End in
             Unavailable Signal State, Carrier Equipment Out of Service,
             DS2 Payload AIS, and DS2 Performance Threshold.

        (11) A read-write line Length object has been added.

        (12) Signal mode of other has been added.

        (13) Added a lineStatus last change, trap and enabler.

        (14) The e1(19) ifType has been obsoleted so this MIB
             does not list it as a supported ifType.

        (15) Textual Conventions for statistics objects have been used.

        (16) A new object, dsx1LoopbackStatus has been introduced to
             reflect the loopbacks established on a DS1 interface and
             the source to the requests.  dsx1LoopbackConfig continues
             to be the desired loopback state while dsx1LoopbackStatus

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             reflects the actual state.

        (17) A dual loopback has been added to allow the setting of an
             inward loopback and a line loopback at the same time.

        (18) An object indicating which channel to use within a parent
             object (i.e. DS3) has been added.

        (19) An object has been added to indicate whether or not this
             DS1/E1 is channelized.

        (20) Line coding type of B6ZS has been added for DS2

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2.  Overview

   These objects are used when the particular media being used to
   realize an interface is a DS1/E1/DS2/E2 interface.  At present, this
   applies to these values of the ifType variable in the Internet-
   standard MIB:

        ds1 (18)

   The definitions contained herein are based on the AT&T T-1 Superframe
   (a.k.a., D4) and Extended Superframe (ESF) formats [AT&T-UM-305],
   [AT&T-TR-54016], the latter of which conforms to ANSI specifications
   [ANSI T1.403], and the CCITT Recommendations [ CCITT-G.703], [ITU-T-
   G.704], referred to as E1 for the rest of this memo.

   The various DS1 and E1 line disciplines are similar enough that
   separate MIBs are unwarranted, although there are some differences.
   For example, Loss of Frame is defined more rigorously in the ESF
   specification than in the D4 specification, but it is defined in
   both.  Therefore,  interface types e1(19) and g703at2mb(67) have been
   obsoleted.

   Where it is necessary to distinguish between the flavors of E1 with
   and without CRC, E1-CRC denotes the "with CRC" form (G.704 Table 4b)
   and E1-noCRC denotes the "without CRC" form (G.704 Table 4a).

2.1.  Use of ifTable for DS1 Layer

   Only the ifGeneralInformationGroup needs to be supported.

           ifTable Object    Use for DS1 Layer
======================================================================
           ifIndex           Interface index.

           ifDescr           See interfaces MIB [RFC2863]

           ifType            ds1(18)

           ifSpeed           Speed of line rate
                             DS1 - 1544000
                             E1  - 2048000
                             DS2 - 6312000
                             E2  - 8448000
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           ifPhysAddress     The value of the Circuit Identifier.
                             If no Circuit Identifier has been assigned
                             this object should have an octet string
                             with zero length.

           ifAdminStatus     See interfaces MIB [RFC2863]

           ifOperStatus      See interfaces MIB [RFC2863]

           ifLastChange      See interfaces MIB [RFC2863]

           ifName            See interfaces MIB [RFC2863].

           ifLinkUpDownTrapEnable   Set to enabled(1).

           ifHighSpeed       Speed of line in Mega-bits per second
                             (2, 6, or 8)

           ifConnectorPresent Set to true(1) normally, except for
                              cases such as DS1/E1 over AAL1/ATM where
                              false(2) is appropriate

2.2.  Usage Guidelines

2.2.1.  Usage of ifStackTable for Routers and DSUs

   The object dsx1IfIndex has been deprecated.  This object previously
   allowed a very special proxy situation to exist for Routers and CSUs.
   This section now describes how to use ifStackTable to represent this
   relationship.

   The paragraphs discussing dsx1IfIndex and dsx1LineIndex have been
   preserved in Appendix A for informational purposes.

   The ifStackTable is used in the proxy case to represent the
   association between pairs of interfaces, e.g. this T1 is attached to
   that T1.  This use is consistent with the use of the ifStackTable to
   show the association between various sub-layers of an interface.  In
   both cases entire PDUs are exchanged between the interface pairs - in
   the case of a T1, entire T1 frames are exchanged; in the case of PPP
   and HDLC, entire HDLC frames are exchanged.  This usage is not meant
   to suggest the use of the ifStackTable to represent Time Division
   Multiplexing (TDM) connections in general.
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   External&Internal interface scenario: the SNMP Agent resides on a
   host external from the device supporting DS1 interfaces (e.g., a
   router). The Agent represents both the host and the DS1 device.

   Example:

   A shelf full of CSUs connected to a Router. An SNMP Agent residing on
   the router proxies for itself and the CSU. The router has also an
   Ethernet interface:

         +-----+
   |     |     |
   |     |     |               +---------------------+
   |E    |     |  1.544  MBPS  |              Line#A | DS1 Link
   |t    |  R  |---------------+ - - - - -  - - -  - +------>
   |h    |     |               |                     |
   |e    |  O  |  1.544  MBPS  |              Line#B | DS1 Link
   |r    |     |---------------+ - - - - - - - - - - +------>
   |n    |  U  |               |  CSU Shelf          |
   |e    |     |  1.544  MBPS  |              Line#C | DS1 Link
   |t    |  T  |---------------+ - - - -- -- - - - - +------>
   |     |     |               |                     |
   |-----|  E  |  1.544  MBPS  |              Line#D | DS1 Link
   |     |     |---------------+ -  - - - -- - - - - +------>
   |     |  R  |               |_____________________|
   |     |     |
   |     +-----+

   The assignment of the index values could for example be:

           ifIndex  Description
           1        Ethernet
           2        Line#A Router
           3        Line#B Router
           4        Line#C Router
           5        Line#D Router
           6        Line#A CSU Router
           7        Line#B CSU Router
           8        Line#C CSU Router
           9        Line#D CSU Router
           10       Line#A CSU Network
           11       Line#B CSU Network
           12       Line#C CSU Network
           13       Line#D CSU Network

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   The ifStackTable is then used to show the relationships between the
   various DS1 interfaces.

           ifStackTable Entries

           HigherLayer   LowerLayer
           2             6
           3             7
           4             8
           5             9
           6             10
           7             11
           8             12
           9             13

   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be identical, except the Ethernet and the 4 router
   interfaces are deleted.  Interfaces would also be numbered from 1 to
   8.

           ifIndex  Description
           1        Line#A CSU Router
           2        Line#B CSU Router
           3        Line#C CSU Router
           4        Line#D CSU Router
           5        Line#A CSU Network
           6        Line#B CSU Network
           7        Line#C CSU Network
           8        Line#D CSU Network

           ifStackTable Entries

           HigherLayer   LowerLayer
           1             5
           2             6
           3             7
           4             8

2.2.2.  Usage of ifStackTable for DS1/E1 on DS2/E2

   An example is given of how DS1/E1 interfaces are stacked on DS2/E2
   interfaces.  It is not necessary nor is it always desirable to
   represent DS2 interfaces.  If this is required, the following
   stacking should be used.  All ifTypes are ds1.  The DS2 is determined
   by examining ifSpeed or dsx1LineType.

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           ifIndex  Description
           1        DS1 #1
           2        DS1 #2
           3        DS1 #3
           4        DS1 #4
           5        DS2

           ifStackTable Entries

           HigherLayer   LowerLayer
           1             5
           2             5
           3             5
           4             5

2.2.3.  Usage of Channelization for DS3, DS1, DS0

   An example is given here to explain the channelization objects in the
   DS3, DS1, and DS0 MIBs to help the implementor use the objects
   correctly. Treatment of E3 and E1 would be similar, with the number
   of DS0s being different depending on the framing of the E1.

   Assume that a DS3 (with ifIndex 1) is Channelized into DS1s (without
   DS2s).  The object dsx3Channelization is set to enabledDs1.  There
   will be 28 DS1s in the ifTable.  Assume the entries in the ifTable
   for the DS1s are created in channel order and the ifIndex values are
   2 through 29. In the DS1 MIB, there will be an entry in the
   dsx1ChanMappingTable for each ds1.  The entries will be as follows:

           dsx1ChanMappingTable Entries

           ifIndex  dsx1Ds1ChannelNumber   dsx1ChanMappedIfIndex
           1        1                      2
           1        2                      3
           ......
           1        28                     29

   In addition, the DS1s are channelized into DS0s.  The object
   dsx1Channelization is set to enabledDS0 for each DS1.   When this
   object is set to this value, 24 DS0s are created by the agent. There
   will be 24 DS0s in the ifTable for each DS1.  If the
   dsx1Channelization is set to disabled, the 24 DS0s are destroyed.
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   Assume the entries in the ifTable are created in channel order and
   the ifIndex values for the DS0s in the first DS1 are 30 through 53.
   In the DS0 MIB, there will be an entry in the dsx0ChanMappingTable
   for each DS0.  The entries will be as follows:

           dsx0ChanMappingTable Entries

           ifIndex   dsx0Ds0ChannelNumber  dsx0ChanMappedIfIndex
           2         1                     30
           2         2                     31
           ......
           2         24                    53

2.2.4.  Usage of Channelization for DS3, DS2, DS1

   An example is given here to explain the channelization objects in the
   DS3 and DS1 MIBs to help the implementor use the objects correctly.

   Assume that a DS3 (with ifIndex 1) is Channelized into DS2s.  The
   object dsx3Channelization is set to enabledDs2.  There will be 7 DS2s
   (ifType of DS1) in the ifTable.  Assume the entries in the ifTable
   for the DS2s are created in channel order and the ifIndex values are
   2 through 8. In the DS1 MIB, there will be an entry in the
   dsx1ChanMappingTable for each DS2.  The entries will be as follows:

           dsx1ChanMappingTable Entries

           ifIndex  dsx1Ds1ChannelNumber   dsx1ChanMappedIfIndex
           1        1                      2
           1        2                      3
           ......
           1        7                      8

   In addition, the DS2s are channelized into DS1s.  The object
   dsx1Channelization is set to enabledDS1 for each DS2.  There will be
   4 DS1s in the ifTable for each DS2.  Assume the entries in the
   ifTable are created in channel order and the ifIndex values for the
   DS1s in the first DS2 are 9 through 12, then 13 through 16 for the
   second DS2, and so on.  In the DS1 MIB, there will be an entry in the
   dsx1ChanMappingTable for each DS1.  The entries will be as follows:

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           dsx1ChanMappingTable Entries

           ifIndex   dsx1Ds1ChannelNumber  dsx1ChanMappedIfIndex
           2         1                     9
           2         2                     10
           2         3                     11
           2         4                     12
           3         1                     13
           3         2                     14
           ...
           8         4                     36

2.2.5.  Usage of Loopbacks

   This section discusses the behaviour of objects related to loopbacks.

   The object dsx1LoopbackConfig represents the desired state of
   loopbacks on this interface.  Using this object a Manager can
   request:
       LineLoopback
       PayloadLoopback (if ESF framing)
       InwardLoopback
       DualLoopback (Line + Inward)
       NoLoopback

   The remote end can also request loopbacks either through the FDL
   channel if ESF or inband if D4.  The loopbacks that can be requested
   this way are:

       LineLoopback
       PayloadLoopback (if ESF framing)
       NoLoopback

   To model the current state of loopbacks on a DS1 interface, the object
   dsx1LoopbackStatus defines which loopback is currently applied to an
   interface.  This objects, which is a bitmap, will have bits turned on
   which reflect the currently active loopbacks on the interface as well
   as the source of those loopbacks.

   The following restrictions/rules apply to loopbacks:

   The far end cannot undo loopbacks set by a manager.

   A manager can undo loopbacks set by the far end.

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   Both a line loopback and an inward loopback can be set at the same time.
   Only these two loopbacks can co-exist and either one may be set by the
   manager or the far end.  A LineLoopback request from the far end is
   incremental to an existing Inward loopback established by a manager. When
   a NoLoopback is received from the far end in this case, the InwardLoopback
   remains in place.

2.3.  Objectives of this MIB Module

   There are numerous things that could be included in a MIB for DS1
   signals:  the management of multiplexors, CSUs, DSUs, and the like.
   The intent of this document is to facilitate the common management of
   all devices with DS1, E1, DS2, or E3 interfaces.  As such, a design
   decision was made up front to very closely align the MIB with the set
   of objects that can generally be read from these types devices that
   are currently deployed.

   J2 interfaces are not supported by this MIB.

2.4.  DS1 Terminology

   The terminology used in this document to describe error conditions on
   a DS1 interface as monitored by a DS1 device are based on the late
   but not final draft of what became the ANSI T1.231 standard [ANSI-
   T1.231].  If the definition in this document does not match the
   definition in the ANSI T1.231 document, the implementer should follow
   the definition described in this document.

2.4.1.  Error Events

     Bipolar Violation (BPV) Error Event
          A BPV error event for an AMI-coded signal is the occurrence of
          a pulse of the same polarity as the previous pulse (See T1.231
          Section 6.1.1.1.1).  A BPV error event for a B8ZS- or HDB3-
          coded signal is the occurrence of a pulse of the same polarity
          as the previous pulse without being a part of the zero
          substitution code.

     Excessive Zeroes (EXZ) Error Event
          An Excessive Zeroes error event for an AMI-coded signal is the
          occurrence of more than fifteen contiguous zeroes (See T1.231
          Section 6.1.1.1.2).  For a B8ZS coded signal, the defect
          occurs when more than seven contiguous zeroes are detected.

      Line Coding Violation (LCV) Error Event

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          A Line Coding Violation (LCV) is the occurrence of either a
          Bipolar Violation (BPV) or Excessive Zeroes (EXZ) Error Event.
          (Also known as CV-L; See T1.231 Section 6.5.1.1.)

     Path Coding Violation (PCV) Error Event
          A Path Coding Violation error event is a frame synchronization
          bit error in the D4 and E1-noCRC formats, or a CRC or frame
          synch. bit error in the ESF and E1-CRC formats. (Also known as
          CV-P; See T1.231 Section 6.5.2.1.)

     Controlled Slip (CS) Error Event
          A Controlled Slip is the replication or deletion of the
          payload bits of a DS1 frame (See T1.231 Section 6.1.1.2.3).  A
          Controlled Slip may be performed when there is a difference
          between the timing of a synchronous receiving terminal and the
          received signal.  A Controlled Slip does not cause an Out of
          Frame defect.

2.4.2.  Performance Defects

     Out Of Frame (OOF) Defect
          An OOF defect is the occurrence of a particular density of
          Framing Error events (See T1.231 Section 6.1.2.2.1).

          For DS1 links, an Out of Frame defect is declared when the
          receiver detects two or more framing errors within a 3 msec
          period for ESF signals and 0.75 msec for D4 signals, or two or
          more errors out of five or fewer consecutive framing-bits.

          For E1 links, an Out Of Frame defect is declared when three
          consecutive frame alignment signals have been received with an
          error (see G.706 Section 4.1 [CCITT-G.706]).

          For DS2 links, an Out of Frame defect is declared when 7 or
          more consecutive errored framing patterns (4 multiframe) are
          received.  The OOF is cleared when 3 or more consecutive
          correct framing patterns are received.

          Once an Out Of Frame Defect is declared, the framer starts
          searching for a correct framing pattern.  The Out of Frame
          defect ends when the signal is in frame.

          In-frame occurs when there are fewer than two frame bit errors
          within 3 msec period for ESF signals and 0.75 msec for D4
          signals.

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          For E1 links, in-frame occurs when a) in frame N the frame
          alignment signal is correct and b) in frame N+1 the frame
          alignment signal is absent (i.e., bit 2 in TS0 is a one) and
          c) in frame N+2 the frame alignment signal is present and
          correct. (See G.704 Section 4.1)

     Alarm Indication Signal (AIS) Defect
          For D4 and ESF links, the 'all ones' condition is detected at
          a DS1 line interface upon observing an unframed signal with a
          one's density of at least 99.9% present for a time equal to or
          greater than T, where 3 ms <= T <= 75 ms.  The AIS is
          terminated upon observing a signal not meeting the one's
          density or the unframed signal criteria for a period equal to
          or greater than than T (See G.775, Section 5.4).

          For E1 links, the 'all-ones' condition is detected at the line
          interface as a string of 512 bits containing fewer than three
          zero bits (see O.162 [CCITT-O.162] Section 3.3.2).

          For DS2 links, the DS2 AIS shall be sent from the NT1 to the
          user to indicate a loss of the 6,312 kbps frame capability on
          the network side.  The DS2 AIS is defined as a bit array of
          6,312 kbps in which all binary bits are set to '1'.

          The DS2 AIS detection and removal shall be implemented
          according to ITU-T Draft Recommendation G.775 [ITU-T G.775]
          Section 5.5:
          - a DS2 AIS defect is detected when the incoming signal has
          two (2) or less ZEROs in a sequence of 3156 bits (0.5 ms).
          - a DS2 AIS defect is cleared when the incoming signal has
          three (3) or more ZEROs in a sequence of 3156 bits (0.5 ms).

2.4.3.  Performance Parameters

   All performance parameters are accumulated in fifteen minute
   intervals and up to 96 intervals (24 hours worth) are kept by an
   agent.  Fewer than 96 intervals of data will be available if the
   agent has been restarted within the last 24 hours.  In addition,
   there is a rolling 24-hour total of each performance parameter.
   Performance parameters continue to be collected when the interface is
   down.

   There is no requirement for an agent to ensure fixed relationship
   between the start of a fifteen minute interval and any wall clock;

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   however some agents may align the fifteen minute intervals with
   quarter hours.

   Performance parameters are of types PerfCurrentCount,
   PerfIntervalCount and PerfTotalCount.  These textual conventions are
   all Gauge32, and they are used because it is possible for these
   objects to decrease.  Objects may decrease when Unavailable Seconds
   occurs across a fifteen minutes interval boundary. See Unavailable
   Seconds discussion later in this section.

     Line Errored Seconds (LES)
          A Line Errored Second is a second in which one or more Line
          Code Violation error events were detected. (Also known as ES-
          L; See T1.231 Section 6.5.1.2.)

     Controlled Slip Seconds (CSS)
          A Controlled Slip Second is a one-second interval containing
          one or more controlled slips (See T1.231 Section 6.5.2.8).
          This is not incremented during an Unavailable Second.

     Errored Seconds (ES)
          For ESF and E1-CRC links an Errored Second is a second with
          one or more Path Code Violation OR one or more Out of Frame
          defects OR one or more Controlled Slip events OR a detected
          AIS defect. (See T1.231 Section 6.5.2.2 and G.826 [ITU-T-
          G.826] Section B.1).

          For D4 and E1-noCRC links, the presence of Bipolar Violations
          also triggers an Errored Second.

          This is not incremented during an Unavailable Second.

     Bursty Errored Seconds (BES)
          A Bursty Errored Second (also known as Errored Second type B
          in T1.231 Section 6.5.2.4) is a second with fewer than 320 and
          more than 1 Path Coding Violation error events, no Severely
          Errored Frame defects and no detected incoming AIS defects.
          Controlled slips are not included in this parameter.

          This is not incremented during an Unavailable Second.  It
          applies to ESF signals only.

     Severely Errored Seconds (SES)
          A Severely Errored Second for ESF signals is a second with 320

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          or more Path Code Violation Error Events OR one or more Out of
          Frame defects OR a detected AIS defect (See T1.231 Section
          6.5.2.5).

          For E1-CRC signals, a Severely Errored Second is a second with
          832 or more Path Code Violation error events OR one or more
          Out of Frame defects.

          For E1-noCRC signals, a Severely Errored Second is a 2048 LCVs
          or more.

          For D4 signals, a Severely Errored Second is a count of one-
          second intervals with Framing Error events, or an OOF defect,
          or 1544 LCVs or more.

          Controlled slips are not included in this parameter.

          This is not incremented during an Unavailable Second.

     Severely Errored Framing Second (SEFS)
          An Severely Errored Framing Second is a second with one or
          more Out of Frame defects OR a detected AIS defect.  (Also
          known as SAS-P (SEF/AIS second); See T1.231 Section 6.5.2.6.)

     Degraded Minutes
          A Degraded Minute is one in which the estimated error rate
          exceeds 1E-6 but does not exceed 1E-3 (see G.821 [CCITT-
          G.821]).

          Degraded Minutes are determined by collecting all of the
          Available Seconds, removing any Severely Errored Seconds
          grouping the result in 60-second long groups and counting a
          60-second long group (a.k.a., minute) as degraded if the
          cumulative errors during the seconds present in the group
          exceed 1E-6.  Available seconds are merely those seconds which
          are not Unavailable as described below.

     Unavailable Seconds (UAS)
          Unavailable Seconds (UAS) are calculated by counting the
          number of seconds that the interface is unavailable.  The DS1
          interface is said to be unavailable from the onset of 10
          contiguous SESs, or the onset of the condition leading to a
          failure (see Failure States).  If the condition leading to the
          failure was immediately preceded by one or more contiguous
          SESs, then the DS1 interface unavailability starts from the

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          onset of these SESs.  Once unavailable, and if no failure is
          present, the DS1 interface becomes available at the onset of
          10 contiguous seconds with no SESs.  Once unavailable, and if
          a failure is present, the DS1 interface becomes available at
          the onset of 10 contiguous seconds with no SESs, if the
          failure clearing time is less than or equal to 10 seconds.  If
          the failure clearing time is more than 10 seconds, the DS1
          interface becomes available at the onset of 10 contiguous
          seconds with no SESs, or the onset period leading to the
          successful clearing condition, whichever occurs later.  With
          respect to the DS1 error counts, all counters are incremented
          while the DS1 interface is deemed available.  While the
          interface is deemed unavailable, the only count that is
          incremented is UASs.

          Note that this definition implies that the agent cannot
          determine until after a ten second interval has passed whether
          a given one-second interval belongs to available or
          unavailable time.  If the agent chooses to update the various
          performance statistics in real time then it must be prepared
          to retroactively reduce the ES, BES, SES, and SEFS counts by
          10 and increase the UAS count by 10 when it determines that
          available time has been entered.  It must also be prepared to
          adjust the PCV count and the DM count as necessary since these
          parameters are not accumulated during unavailable time.  It
          must be similarly prepared to retroactively decrease the UAS
          count by 10 and increase the ES, BES, and DM counts as
          necessary upon entering available time.  A special case exists
          when the 10 second period leading to available or unavailable
          time crosses a 900 second statistics window boundary, as the
          foregoing description implies that the ES, BES, SES, SEFS, DM,
          and UAS counts the PREVIOUS interval must be adjusted.  In
          this case successive GETs of the affected dsx1IntervalSESs and
          dsx1IntervalUASs objects will return differing values if the
          first GET occurs during the first few seconds of the window.

          The agent may instead choose to delay updates to the various
          statistics by 10 seconds in order to avoid retroactive
          adjustments to the counters.  A way to do this is sketched in
          Appendix B.

   In any case, a linkDown trap shall be sent only after the agent has
   determined for certain that the unavailable state has been entered,
   but the time on the trap will be that of the first UAS (i.e., 10
   seconds earlier).  A linkUp trap shall be handled similarly.

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   According to ANSI T1.231 unavailable time begins at the _onset_ of 10
   contiguous severely errored seconds -- that is, unavailable time
   starts with the _first_ of the 10 contiguous SESs.  Also, while an
   interface is deemed unavailable all counters for that interface are
   frozen except for the UAS count.  It follows that an implementation
   which strictly complies with this standard must _not_ increment any
   counters other than the UAS count -- even temporarily -- as a result
   of anything that happens during those 10 seconds.  Since changes in
   the signal state lag the data to which they apply by 10 seconds, an
   ANSI-compliant implementation must pass the the one-second statistics
   through a 10-second delay line prior to updating any counters.  That
   can be done by performing the following steps at the end of each one
   second interval.

   i)   Read near/far end CV counter and alarm status flags from the
        hardware.

   ii)  Accumulate the CV counts for the preceding second and
        compare them to the ES and SES threshold for the layer
        in question.  Update the signal state and shift the
        one-second CV counts and ES/SES flags into the 10-element
        delay line.  Note that far-end one-second statistics are
        to be flagged as "absent" during any second in which there
        is an incoming defect at the layer in question or at any
        lower layer.

   iii) Update the current interval statistics using the signal
        state from the _previous_ update cycle and the one-second
        CV counts and ES/SES flags shifted out of the 10-element
        delay line.

   This approach is further described in Appendix B.

2.4.4.  Failure States

   The following failure states are received, or detected failures, that
   are reported in the dsx1LineStatus object.  When a DS1 interface
   would, if ever, produce the conditions leading to the failure state
   is described in the appropriate specification.

     Far End Alarm Failure
          The Far End Alarm failure is also known as "Yellow Alarm" in
          the DS1 case, "Distant Alarm" in the E1 case, and "Remote
          Alarm" in the DS2 case.

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          For D4 links, the Far End Alarm failure is declared when bit 6
          of all channels has been zero for at least 335 ms and is
          cleared when bit 6 of at least one channel is non-zero for a
          period T, where T is usually less than one second and always
          less than 5 seconds.  The Far End Alarm failure is not
          declared for D4 links when a Loss of Signal is detected.

          For ESF links, the Far End Alarm failure is declared if the
          Yellow Alarm signal pattern occurs in at least seven out of
          ten contiguous 16-bit pattern intervals and is cleared if the
          Yellow Alarm signal pattern does not occur in ten contiguous
          16-bit signal pattern intervals.

          For E1 links, the Far End Alarm failure is declared when bit 3
          of time-slot zero is received set to one on two consecutive
          occasions.  The Far End Alarm failure is cleared when bit 3 of
          time-slot zero is received set to zero.

          For DS2 links, if a loss of frame alignment (LOF or LOS)
          and/or DS2 AIS condition, is detected, the RAI signal shall be
          generated and transmitted to the remote side.

          The Remote Alarm Indication(RAI) signal is defined on m-bits
          as a repetition of the 16bit sequence consisting of eight
          binary '1s' and eight binary '0s' in m-bits(1111111100000000).
          When the RAI signal is not sent (in normal operation),the HDLC
          flag pattern (01111110) in the m-bit is sent.

          The RAI failure is detected when 16 or more consecutive RAI-
          patterns (1111111100000000) are received.  The RAI failure is
          cleared when 4 or more consecutive incorrect-RAI-patterns are
          received.

     Alarm Indication Signal (AIS) Failure
          The Alarm Indication Signal failure is declared when an AIS
          defect is detected at the input and the  AIS defect still
          exists after the Loss Of Frame failure (which is caused by the
          unframed nature of the 'all-ones' signal) is declared. The AIS
          failure is cleared when the Loss Of Frame failure is cleared.
          (See T1.231 Section 6.2.1.2.1)

          An AIS defect at a 6312 kbit/s (G.704) interface is detected
          when the incoming signal has two {2} or less ZEROs in a
          sequence of 3156 bits (0.5ms).
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          The AIS signal defect is cleared when the incoming signal has
          three {3} or more ZEROs in a sequence of 3156 bits (0.5ms).

     Loss Of Frame Failure
          For DS1 links, the Loss Of Frame failure is declared when an
          OOF or LOS  defect has persisted for T seconds, where 2 <= T
          <= 10.  The Loss Of Frame failure is cleared when there have
          been no OOF or LOS defects during a period T where 0 <= T <=
          20.  Many systems will perform "hit integration" within the
          period T before declaring or clearing the failure e.g., see TR
          62411 [AT&T-TR-62411].

          For E1 links, the Loss Of Frame Failure is declared when an
          OOF defect is detected.

     Loss Of Signal Failure
          For DS1, the Loss Of Signal failure is declared upon observing
          175 +/- 75 contiguous pulse positions with no pulses of either
          positive or negative polarity.  The LOS failure is cleared
          upon observing an average pulse density of at least 12.5% over
          a period of 175 +/- 75 contiguous pulse positions starting
          with the receipt of a pulse.

          For E1 links, the Loss Of Signal failure is declared when
          greater than 10 consecutive zeroes are detected (see O.162
          Section 3.4.4).

          A LOS defect at 6312kbit/s interfaces is detected when the
          incoming signal has "no transitions", i.e. when the signal
          level is less than or equal to a signal level of 35dB below
          nominal, for N consecutive pulse intervals, where 10 <=N<=255.

          The LOS defect is cleared when the incoming signal has
          "transitions", i.e. when the signal level is greater than or
          equal to a signal level of 9dB below nominal, for N
          consecutive pulse intervals, where 10<=N<=255.

          A signal with "transitions" corresponds to a G.703 compliant
          signal.

     Loopback Pseudo-Failure
          The Loopback Pseudo-Failure is declared when the near end
          equipment has placed a loopback (of any kind) on the DS1.
          This allows a management entity to determine from one object
          whether the DS1 can be considered to be in service or not

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          (from the point of view of the near end equipment).

     TS16 Alarm Indication Signal Failure
          For E1 links, the TS16 Alarm Indication Signal failure is
          declared when time-slot 16 is received as all ones for all
          frames of two consecutive multiframes (see G.732 Section
          4.2.6).  This condition is never declared for DS1.

     Loss Of MultiFrame Failure
          The Loss Of MultiFrame failure is declared when two
          consecutive multiframe alignment signals (bits 4 through 7 of
          TS16 of frame 0) have been received with an error.  The Loss
          Of Multiframe failure is cleared when the first correct
          multiframe alignment signal is received.  The Loss Of
          Multiframe failure can only be declared for E1 links operating
          with G.732 [CCITT-G.732] framing (sometimes called "Channel
          Associated Signalling" mode).

     Far End Loss Of Multiframe Failure
          The Far End Loss Of Multiframe failure is declared when bit 2
          of TS16 of frame 0 is received set to one on two consecutive
          occasions.  The Far End Loss Of Multiframe failure is cleared
          when bit 2 of TS16 of frame 0 is received set to zero.  The
          Far End Loss Of Multiframe failure can only be declared for E1
          links operating in "Channel Associated Signalling" mode (See
          G.732).

     DS2 Payload AIS Failure
          The DS2 Payload AIS is detected when the incoming signal of
          the 6,312 kbps frame payload [TS1-TS96] has 2 or less 0's in a
          sequence of 3072 bits (0.5ms).  The DS2 Payload AIS is cleared
          when the incoming signal of the 6,312 kbps frame payload
          [TS1-TS96] has 3 or more 0's in a sequence of 3072 bits (0.5
          ms).

     DS2 Performance Threshold
          DS2 Performance Threshold Failure monitors equipment
          performance and is based on the CRC (Cyclic Redundancy Check)
          Procedure defined in G.704.

          The DS2 Performance Threshold Failure is detected when the bit
          error ratio exceeds 10^-4 (Performance Threshold), and the DS2
          Performance Threshold Failure shall be cleared when the bit
          error ratio decreased to less than 10^-6."
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2.4.5.  Other Terms

     Circuit Identifier
       This is a character string specified by the circuit
       vendor, and is useful when communicating with the vendor
       during the troubleshooting process (see M.1400 [ITU-T-M.1400] for
       additional information).

     Proxy
       In this document, the word proxy is meant to indicate an
       application which receives SNMP messages and replies to them on
       behalf of the devices which implement the actual DS1/E1
       interfaces.  The proxy may have already collected the information
       about the DS1/E1 interfaces into its local database and may not
       necessarily forward the requests to the actual DS1/E1 interface.
       It is expected in such an application that there are periods of
       time where the proxy is not communicating with the DS1/E1
       interfaces.  In these instances the proxy will not necessarily
       have up-to-date configuration information and will most likely
       have missed the collection of some statistics data.  Missed
       statistics data collection will result in invalid data in the
       interval table.

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3.  Object Definitions

          DS1-MIB DEFINITIONS ::= BEGIN

          IMPORTS
               MODULE-IDENTITY, OBJECT-TYPE,
               NOTIFICATION-TYPE, transmission         FROM SNMPv2-SMI
               DisplayString, TimeStamp, TruthValue    FROM SNMPv2-TC
               MODULE-COMPLIANCE, OBJECT-GROUP,
               NOTIFICATION-GROUP                      FROM SNMPv2-CONF
               InterfaceIndex, ifIndex                 FROM IF-MIB
               PerfCurrentCount, PerfIntervalCount,
               PerfTotalCount                          FROM PerfHist-TC-MIB;

          ds1 MODULE-IDENTITY
              LAST-UPDATED "200401110000Z"
              ORGANIZATION "IETF AToM MIB Working Group"
              CONTACT-INFO
                "WG charter:
                 http://www.ietf.org/html.charters/atommib-charter.html

                 Mailing Lists:
                   General Discussion: atommib@research.telcordia.com
                   To Subscribe: atommib-request@research.telcordia.com

                 Editor: Orly Nicklass

                 Postal: RAD Data Communications, Ltd.
                         Ziv Tower, 24 Roul Walenberg
                         Tel Aviv, Israel, 69719

                         Tel: +9723 765 9969
                 E-mail: orly_n@rad.com"

              DESCRIPTION
                   "The MIB module to describe DS1, E1, DS2, and
                    E2 interfaces objects.

                    Copyright (c) The Internet Society (2003).  This
                    version of this MIB module is part of RFC yyyy;
                    see the RFC itself for full legal notices."
          -- RFC Ed.: replace yyyy with actual RFC number & remove this notice

              REVISION "200401110000Z"

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              DESCRIPTION
                   "The RFC yyyy version of this MIB module.
          -- RFC Ed.: replace yyyy with actual RFC number & remove this notice
                    The key changes made to this MIB module
                    since its publication in RFC 2495 are as follows:
               (1) The dsx1FracIfIndex SYNTAX matches the description range.
               (2) A value was added to dsx1TransmitClockSource.
               (3) Values were added to dsx1LineType.
               (4) Two objects were added, dsx1LineMode and dsx1LineBuildOut
                   to better express transceiver mode and LineBuildOut for T1.
               (5) Reference was added to Circuit Identifier object.
               (6) Align the DESCRIPTION clauses of few statistic objects with
                   the near end definition, the far end definition and with
                   RFC3593.
               (7) Changes in Compliance Statements to include new objects.
               (8) A typographical error in dsx2E2 was fixed, new name is dsx1E2."

              REVISION "199808011830Z"
              DESCRIPTION
                   "The RFC 2495 version of this MIB module.
                    The key changes made to this MIB module
                    since its publication in RFC 1406 are as follows:
               (1)  The Fractional Table has been deprecated.
               (2)  This document uses SMIv2.
               (3)  Usage is given for ifTable and ifXTable.
               (4)  Example usage of ifStackTable is included.
               (5)  dsx1IfIndex has been deprecated.
               (6)  Support for DS2 and E2 have been added.
               (7)  Additional lineTypes for DS2, E2, and unframed E1
                    were added.
               (8)  The definition of valid intervals has been clarified
                    for the case where the agent proxied for other devices.  In
                    particular, the treatment of missing intervals has been
                    clarified.
               (9)  An inward loopback has been added.
               (10) Additional lineStatus bits have been added for Near End in
                    Unavailable Signal State, Carrier Equipment Out of Service,
                    DS2 Payload AIS, and DS2 Performance Threshold.
               (11) A read-write line Length object has been added.
               (12) Signal mode of other has been added.
               (13) Added a lineStatus last change, trap and enabler.
               (14) The e1(19) ifType has been obsoleted so this MIB
                    does not list it as a supported ifType.
               (15) Textual Conventions for statistics objects have been used.
               (16) A new object, dsx1LoopbackStatus has been introduced to

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                    reflect the loopbacks established on a DS1 interface and
                    the source to the requests.  dsx1LoopbackConfig continues
                    to be the desired loopback state while dsx1LoopbackStatus
                    reflects the actual state.
               (17) A dual loopback has been added to allow the setting of an
                    inward loopback and a line loopback at the same time.
               (18) An object indicating which channel to use within a parent
                    object (i.e. DS3) has been added.
               (19) An object has been added to indicate whether or not this
                    DS1/E1 is channelized.
               (20) Line coding type of B6ZS has been added for DS2"

              REVISION "199301252028Z"
              DESCRIPTION
                   "Initial version, published as RFC 1406."

              ::= { transmission 18 }

          -- note that this subsumes cept (19) and g703at2mb (67)
          -- there is no separate CEPT or G703AT2MB MIB

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          -- The DS1 Near End Group

          -- The DS1 Near End Group consists of five tables:
          --    DS1 Configuration
          --    DS1 Current
          --    DS1 Interval
          --    DS1 Total
          --    DS1 Channel Table

          -- The DS1 Configuration Table

          dsx1ConfigTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1ConfigEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Configuration table."
               ::= { ds1 6 }

          dsx1ConfigEntry OBJECT-TYPE
               SYNTAX  Dsx1ConfigEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Configuration table."
               INDEX   { dsx1LineIndex }
               ::= { dsx1ConfigTable 1 }

          Dsx1ConfigEntry ::=
               SEQUENCE {
                     dsx1LineIndex                        InterfaceIndex,
                     dsx1IfIndex                          InterfaceIndex,
                     dsx1TimeElapsed                      INTEGER,
                     dsx1ValidIntervals                   INTEGER,
                     dsx1LineType                         INTEGER,
                     dsx1LineCoding                       INTEGER,
                     dsx1SendCode                         INTEGER,
                     dsx1CircuitIdentifier                DisplayString,
                     dsx1LoopbackConfig                   INTEGER,
                     dsx1LineStatus                       INTEGER,
                     dsx1SignalMode                       INTEGER,
                     dsx1TransmitClockSource              INTEGER,
                     dsx1Fdl                              INTEGER,
                     dsx1InvalidIntervals                 INTEGER,
                     dsx1LineLength                       INTEGER,

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                     dsx1LineStatusLastChange             TimeStamp,
                     dsx1LineStatusChangeTrapEnable       INTEGER,
                     dsx1LoopbackStatus                   INTEGER,
                     dsx1Ds1ChannelNumber                 INTEGER,
                     dsx1Channelization                   INTEGER,
                     dsx1LineMode                         INTEGER,
                     dsx1LineBuildOut                     INTEGER
          }

          dsx1LineIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "This object should be made equal to ifIndex.  The
                      next paragraph describes its previous usage.
                      Making the object equal to ifIndex allows proper
                      use of ifStackTable and ds0/ds0bundle mibs.

                      Previously, this object is the identifier of a DS1
                      Interface on a managed device.  If there is an
                      ifEntry that is directly associated with this and
                      only this DS1 interface, it should have the same
                      value as ifIndex.  Otherwise, number the
                      dsx1LineIndices with an unique identifier
                      following the rules of choosing a number that is
                      greater than ifNumber and numbering the inside
                      interfaces (e.g., equipment side) with even
                      numbers and outside interfaces (e.g, network side)
                      with odd numbers."
               ::= { dsx1ConfigEntry 1 }

          dsx1IfIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  deprecated
               DESCRIPTION
                      "This value for this object is equal to the value
                      of ifIndex from the Interfaces table of MIB II
                      (RFC 1213)."
               ::= { dsx1ConfigEntry 2 }

          dsx1TimeElapsed OBJECT-TYPE
               SYNTAX  INTEGER (0..899)

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               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of seconds that have elapsed since the
                      beginning of the near end current error-
                      measurement period. If, for some reason, such as
                      an adjustment in the system's time-of-day clock,
                      the current interval exceeds the maximum value,
                      the agent will return the maximum value."
               ::= { dsx1ConfigEntry 3 }

          dsx1ValidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of previous near end intervals for
                      which data was collected.  The value will be 96
                      unless the interface was brought online within the
                      last 24 hours, in which case the value will be the
                      number of complete 15 minute near end intervals
                      since the interface has been online.  In the case
                      where the agent is a proxy, it is possible that
                      some intervals are unavailable.  In this case,
                      this interval is the maximum interval number for
                      which data is available."
               ::= { dsx1ConfigEntry 4 }

          dsx1LineType OBJECT-TYPE
               SYNTAX  INTEGER {
                          other(1),
                          dsx1ESF(2),
                          dsx1D4(3),
                          dsx1E1(4),
                          dsx1E1CRC(5),
                          dsx1E1MF(6),
                          dsx1E1CRCMF(7),
                          dsx1Unframed(8),
                          dsx1E1Unframed(9),
                          dsx1DS2M12(10),
                          dsx1E2(11),
                          dsx1E1Q50(12),
                          dsx1E1Q50CRC(13)
                      }
               MAX-ACCESS  read-write

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               STATUS  current
               DESCRIPTION
                      "This variable indicates  the  variety  of  DS1
                      Line  implementing  this  circuit.  The type of
                      circuit affects the number of bits  per  second
                      that  the circuit can reasonably carry, as well
                      as the interpretation of the  usage  and  error
                      statistics. The values, in sequence, describe:

                            TITLE:         SPECIFICATION:
                            dsx1ESF        Extended SuperFrame DS1
                                                 (T1.107)
                            dsx1D4         AT&T D4 format DS1 (T1.107)
                            dsx1E1         ITU-T Recommendation G.704
                                                 (Table 4a)
                            dsx1E1-CRC     ITU-T Recommendation G.704
                                                 (Table 4b)
                            dsxE1-MF       G.704 (Table 4a) with TS16
                                                  multiframing enabled
                            dsx1E1-CRC-MF  G.704 (Table 4b) with TS16
                                                 multiframing enabled
                            dsx1Unframed   DS1 with No Framing
                            dsx1E1Unframed E1 with No Framing (G.703)
                            dsx1DS2M12     DS2 frame format (T1.107)
                            dsx1E2         E2 frame format (G.704)
                            dsx1E1Q50      TS16 bits 5,7,8 set to 101, [in
                                             all other cases it is set
                                             to 111.](ITU-T G.704,table 14)
                            dsx1E1Q50CRC   E1Q50 with CRC.

                      For clarification, the capacity for each E1 type
                      is as listed below:
                      dsx1E1Unframed - E1, no framing = 32 x 64k = 2048k
                      dsx1E1 or dsx1E1CRC - E1, with framing,
                         no signalling = 31 x 64k = 1984k
                      dsx1E1MF or dsx1E1CRCMF - E1, with framing,
                         signalling = 30 x 64k = 1920k"
              REFERENCE
                      "American National Standard for telecommunications -
                         digital hierarchy - formats specification,
                         ANSI T1.107- 1988.
                      CCITT Specifications Volume III, Recommendation
                         G.703, Physical/Electrical Characteristics
                         of Hierarchical Digital Interfaces, April 1991.
                      ITU-T G.704: Synchronous frame structures used at

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                         1544, 6312, 2048, 8488 and 44 736 kbit/s
                         Hierarchical Levels, July 1995."
               ::= { dsx1ConfigEntry 5 }

          dsx1LineCoding OBJECT-TYPE
               SYNTAX  INTEGER {
                          dsx1JBZS (1),
                          dsx1B8ZS (2),
                          dsx1HDB3 (3),
                          dsx1ZBTSI (4),
                          dsx1AMI (5),
                          other(6),
                          dsx1B6ZS(7)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable describes the variety of Zero Code
                      Suppression used on this interface, which in turn
                      affects a number of its characteristics.

                      dsx1JBZS refers the Jammed Bit Zero Suppression,
                      in which the AT&T specification of at least one
                      pulse every 8 bit periods is literally implemented
                      by forcing a pulse in bit 8 of each channel.
                      Thus, only seven bits per channel, or 1.344 Mbps,
                      is available for data.

                      dsx1B8ZS refers to the use of a specified pattern
                      of normal bits and bipolar violations which are
                      used to replace a sequence of eight zero bits.

                      ANSI Clear Channels may use dsx1ZBTSI, or Zero
                      Byte Time Slot Interchange.

                      E1 links, with or without CRC, use dsx1HDB3 or
                      dsx1AMI.

                      dsx1AMI refers to a mode wherein no zero code
                      suppression is present and the line encoding does
                      not solve the problem directly.  In this
                      application, the higher layer must provide data
                      which meets or exceeds the pulse density
                      requirements, such as inverting HDLC data.
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                      dsx1B6ZS refers to the user of a specifed pattern
                      of normal bits and bipolar violations which are
                      used to replace a sequence of six zero bits.  Used
                      for DS2."

               ::= { dsx1ConfigEntry 6 }

          dsx1SendCode OBJECT-TYPE
               SYNTAX  INTEGER {
                         dsx1SendNoCode(1),
                         dsx1SendLineCode(2),
                         dsx1SendPayloadCode(3),
                         dsx1SendResetCode(4),
                         dsx1SendQRS(5),
                         dsx1Send511Pattern(6),
                         dsx1Send3in24Pattern(7),
                         dsx1SendOtherTestPattern(8)
                         }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable indicates what type of code is
                      being sent across the DS1 interface by the device.
                      Setting this variable causes the interface to send
                      the code requested.  The values mean:
                dsx1SendNoCode
                     sending looped or normal data

                dsx1SendLineCode
                     sending a request for a line loopback

                dsx1SendPayloadCode
                     sending a request for a payload loopback

                dsx1SendResetCode
                     sending a loopback termination request

                dsx1SendQRS
                     sending a Quasi-Random Signal  (QRS)  test
                     pattern

                dsx1Send511Pattern
                     sending a 511 bit fixed test pattern

                dsx1Send3in24Pattern

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                     sending a fixed test pattern of 3 bits set
                     in 24

                dsx1SendOtherTestPattern
                     sending a test pattern  other  than  those
                     described by this object"
               ::= { dsx1ConfigEntry 7 }

          dsx1CircuitIdentifier OBJECT-TYPE
               SYNTAX  DisplayString (SIZE (0..255))
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable contains the transmission vendor's
                      circuit identifier, for the purpose of
                      facilitating troubleshooting."
               REFERENCE "ITU-T M.1400"
               ::= { dsx1ConfigEntry 8 }

          dsx1LoopbackConfig OBJECT-TYPE
               SYNTAX  INTEGER {
                           dsx1NoLoop(1),
                           dsx1PayloadLoop(2),
                           dsx1LineLoop(3),
                           dsx1OtherLoop(4),
                           dsx1InwardLoop(5),
                           dsx1DualLoop(6)
                         }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "This variable represents the desired loopback
                      configuration of the DS1 interface.  Agents
                      supporting read/write access should return
                      inconsistentValue in response to a requested
                      loopback state that the interface does not
                      support.  The values mean:

                      dsx1NoLoop
                       Not in the loopback state.  A device that is not
                      capable of performing a loopback on the interface
                      shall always return this as its value.

                      dsx1PayloadLoop

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                       The received signal at this interface is looped
                      through the device.  Typically the received signal
                      is looped back for retransmission after it has
                      passed through the device's framing function.

                      dsx1LineLoop
                       The received signal at this interface does not go
                      through the device (minimum penetration) but is
                      looped back out.

                      dsx1OtherLoop
                       Loopbacks that are not defined here.

                      dsx1InwardLoop
                       The transmitted signal at this interface is
                      looped back and received by the same interface.
                      What is transmitted onto the line is product
                      dependent.

                      dsx1DualLoop
                       Both dsx1LineLoop and dsx1InwardLoop will be
                      active simultaneously."
               ::= { dsx1ConfigEntry 9 }

          dsx1LineStatus OBJECT-TYPE
               SYNTAX  INTEGER (1..131071)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "This variable indicates the Line Status of the
                      interface.  It contains loopback, failure,
                      received 'alarm' and transmitted 'alarms
                      information.

                      The dsx1LineStatus is a bit map represented as a
                      sum, therefore, it can represent multiple failures
                      (alarms) and a LoopbackState simultaneously.

                      dsx1NoAlarm must be set if and only if no other
                      flag is set.

                      If the dsx1loopbackState bit is set, the loopback
                      in effect can be determined from the
                      dsx1loopbackConfig object.  The various bit
                      positions are:

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                1     dsx1NoAlarm           No alarm present
                2     dsx1RcvFarEndLOF      Far end LOF (a.k.a., Yellow Alarm)
                4     dsx1XmtFarEndLOF      Near end sending LOF Indication
                8     dsx1RcvAIS            Far end sending AIS
               16     dsx1XmtAIS            Near end sending AIS
               32     dsx1LossOfFrame       Near end LOF (a.k.a., Red Alarm)
               64     dsx1LossOfSignal      Near end Loss Of Signal
              128     dsx1LoopbackState     Near end is looped
              256     dsx1T16AIS            E1 TS16 AIS
              512     dsx1RcvFarEndLOMF     Far End Sending TS16 LOMF
             1024     dsx1XmtFarEndLOMF     Near End Sending TS16 LOMF
             2048     dsx1RcvTestCode       Near End detects a test code
             4096     dsx1OtherFailure      any line status not defined here
             8192     dsx1UnavailSigState   Near End in Unavailable Signal
                                            State
            16384     dsx1NetEquipOOS       Carrier Equipment Out of Service
            32768     dsx1RcvPayloadAIS     DS2 Payload AIS
            65536     dsx1Ds2PerfThreshold  DS2 Performance Threshold
                                            Exceeded"
               ::= { dsx1ConfigEntry 10 }

          dsx1SignalMode OBJECT-TYPE
               SYNTAX  INTEGER {
                          none (1),
                          robbedBit (2),
                          bitOriented (3),
                          messageOriented (4),
                          other (5)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                 "'none' indicates that no bits are reserved for
                 signaling on this channel.

                 'robbedBit' indicates that DS1 Robbed Bit  Sig-
                 naling is in use.

                 'bitOriented' indicates that E1 Channel  Asso-
                 ciated Signaling is in use.

                 'messageOriented' indicates that Common  Chan-
                 nel Signaling is in use either on channel 16 of
                 an E1 link or channel 24 of a DS1."

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               ::= { dsx1ConfigEntry 11 }

          dsx1TransmitClockSource OBJECT-TYPE
               SYNTAX  INTEGER {
                          loopTiming(1),
                          localTiming(2),
                          throughTiming(3),
                          adaptive (4)
                      }
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                 "The source of Transmit Clock.
                  'loopTiming' indicates that the recovered re-
                 ceive clock is used as the transmit clock.

                  'localTiming' indicates that a local clock
                 source is used or when an external clock is
                 attached to the box containing the interface.

                  'throughTiming' indicates that recovered re-
                 ceive clock from another interface is used as
                 the transmit clock.

                  'adaptive' indicates that the clock is recovered
                 based on the data flow and not based on the
                 physical layer"
               ::= { dsx1ConfigEntry 12 }

          dsx1Fdl OBJECT-TYPE
               SYNTAX  INTEGER (1..15)
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                 "This bitmap describes the use of  the  facili-
                 ties data link, and is the sum of the capabili-
                 ties.  Set any bits that are appropriate:

                 other(1),
                 dsx1AnsiT1403(2),
                 dsx1Att54016(4),
                 dsx1FdlNone(8)

                  'other' indicates that a protocol  other  than
                 one following is used.

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                  'dsx1AnsiT1403' refers to the  FDL  exchange
                 recommended by ANSI.

                  'dsx1Att54016' refers to ESF FDL exchanges.

                  'dsx1FdlNone' indicates that the device  does
                 not use the FDL."
               ::= { dsx1ConfigEntry 13 }

          dsx1InvalidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      " The number of intervals in the range from 0 to
                      dsx1ValidIntervals for which no data is available.
                      This object will typically be zero except in cases
                      where the data for some intervals are not
                      available (e.g., in proxy situations)."
               ::= { dsx1ConfigEntry 14 }

          dsx1LineLength OBJECT-TYPE
               SYNTAX  INTEGER (0..64000)
               UNITS  "meters"
               MAX-ACCESS  read-write
               STATUS  current
               DESCRIPTION
                      "The length of the ds1 line in meters. This
                      objects provides information for line build out
                      circuitry.  This object is only useful if the
                      interface has configurable line build out
                      circuitry."
               ::= { dsx1ConfigEntry 15 }

          dsx1LineStatusLastChange OBJECT-TYPE
               SYNTAX  TimeStamp
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The value of MIB II's sysUpTime object at the
                      time this DS1 entered its current line status
                      state.  If the current state was entered prior to
                      the last re-initialization of the proxy-agent,
                      then this object contains a zero value."
               ::= { dsx1ConfigEntry 16 }

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          dsx1LineStatusChangeTrapEnable  OBJECT-TYPE
               SYNTAX      INTEGER {
                              enabled(1),
                              disabled(2)
                           }
               MAX-ACCESS  read-write
               STATUS      current
               DESCRIPTION
                      "Indicates whether dsx1LineStatusChange traps
                      should be generated for this interface."
               DEFVAL { disabled }
               ::= { dsx1ConfigEntry 17 }

          dsx1LoopbackStatus  OBJECT-TYPE
               SYNTAX      INTEGER (1..127)
               MAX-ACCESS  read-only
               STATUS      current
               DESCRIPTION
                      "This variable represents the current state of the
                      loopback on the DS1 interface.  It contains
                      information about loopbacks established by a
                      manager and remotely from the far end.

                      The dsx1LoopbackStatus is a bit map represented as
                      a sum, therefore is can represent multiple
                      loopbacks simultaneously.

                      The various bit positions are:
                       1  dsx1NoLoopback
                       2  dsx1NearEndPayloadLoopback
                       4  dsx1NearEndLineLoopback
                       8  dsx1NearEndOtherLoopback
                      16  dsx1NearEndInwardLoopback
                      32  dsx1FarEndPayloadLoopback
                      64  dsx1FarEndLineLoopback"

               ::= { dsx1ConfigEntry 18 }

          dsx1Ds1ChannelNumber  OBJECT-TYPE
               SYNTAX      INTEGER (0..28)
               MAX-ACCESS  read-only
               STATUS      current
               DESCRIPTION
                      "This variable represents the channel number of
                      the DS1/E1 on its parent DS2/E2 or DS3/E3.  A

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                      value of 0 indicated this DS1/E1 does not have a
                      parent DS3/E3."

               ::= { dsx1ConfigEntry 19 }

          dsx1Channelization  OBJECT-TYPE
               SYNTAX      INTEGER {
                              disabled(1),
                              enabledDs0(2),
                              enabledDs1(3)
                           }
               MAX-ACCESS  read-write
               STATUS      current
               DESCRIPTION
                      "Indicates whether this ds1/e1 is channelized or
                      unchannelized.  The value of enabledDs0 indicates
                      that this is a DS1 channelized into DS0s.  The
                      value of enabledDs1 indicated that this is a DS2
                      channelized into DS1s.  Setting this value will
                      cause the creation or deletion of entries in the
                      ifTable for the DS0s that are within the DS1."
               ::= { dsx1ConfigEntry 20 }

          dsx1LineMode  OBJECT-TYPE
               SYNTAX      INTEGER {
                              csu(1),
                              dsu(2)
                            }
               MAX-ACCESS  read-write
               STATUS      current
               DESCRIPTION
                      "This setting puts the T1 framer into either long
                      haul (CSU) mode or short haul (DSU) mode."
               ::= { dsx1ConfigEntry 21 }

          dsx1LineBuildOut  OBJECT-TYPE
               SYNTAX      INTEGER {
                              notApplicable (1),
                              neg75dB (2),
                              neg15dB (3),
                              neg225dB (4),
                              zerodB (5)
                           }
               MAX-ACCESS  read-write
               STATUS      current

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               DESCRIPTION
                      "Attenuation setting for T1 framer in long haul
                      (CSU) mode.  The optional values are: -7.5dB,
                      -15dB, -22.5dB and 0dB."
               ::= { dsx1ConfigEntry 22 }

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          -- The DS1 Current Table
          dsx1CurrentTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1CurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 current table contains various statistics
                      being collected for the current 15 minute
                      interval."
               ::= { ds1 7 }

          dsx1CurrentEntry OBJECT-TYPE
               SYNTAX  Dsx1CurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Current table."
                           INDEX   { dsx1CurrentIndex }
                           ::= { dsx1CurrentTable 1 }

          Dsx1CurrentEntry ::=
               SEQUENCE {
                   dsx1CurrentIndex            InterfaceIndex,
                   dsx1CurrentESs              PerfCurrentCount,
                   dsx1CurrentSESs             PerfCurrentCount,
                   dsx1CurrentSEFSs            PerfCurrentCount,
                   dsx1CurrentUASs             PerfCurrentCount,
                   dsx1CurrentCSSs             PerfCurrentCount,
                   dsx1CurrentPCVs             PerfCurrentCount,
                   dsx1CurrentLESs             PerfCurrentCount,
                   dsx1CurrentBESs             PerfCurrentCount,
                   dsx1CurrentDMs              PerfCurrentCount,
                   dsx1CurrentLCVs             PerfCurrentCount
          }

          dsx1CurrentIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies  the
                      DS1 interface to which this entry is applicable.
                      The interface identified by a particular value of
                      this index is the same interface as identified by

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                      the same value as a dsx1LineIndex object
                      instance."
               ::= { dsx1CurrentEntry 1 }

          dsx1CurrentESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Errored Seconds."
               ::= { dsx1CurrentEntry 2 }

          dsx1CurrentSESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Seconds."
               ::= { dsx1CurrentEntry 3 }

          dsx1CurrentSEFSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Framing Seconds."
               ::= { dsx1CurrentEntry 4 }

          dsx1CurrentUASs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds."
               ::= { dsx1CurrentEntry 5 }

          dsx1CurrentCSSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Controlled Slip Seconds."
               ::= { dsx1CurrentEntry 6 }

          dsx1CurrentPCVs OBJECT-TYPE

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               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Path Coding Violations."
               ::= { dsx1CurrentEntry 7 }

          dsx1CurrentLESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Line Errored Seconds."
               ::= { dsx1CurrentEntry 8 }

          dsx1CurrentBESs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds."
               ::= { dsx1CurrentEntry 9 }

          dsx1CurrentDMs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes."
               ::= { dsx1CurrentEntry 10 }

          dsx1CurrentLCVs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Line Code Violations (LCVs)."
               ::= { dsx1CurrentEntry 11 }

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          -- The DS1 Interval Table
          dsx1IntervalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1IntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Interval Table contains various
                      statistics collected by each DS1 Interface over
                      the previous 24 hours of operation.  The past 24
                      hours are broken into 96 completed 15 minute
                      intervals.  Each row in this table represents one
                      such interval (identified by dsx1IntervalNumber)
                      for one specific instance (identified by
                      dsx1IntervalIndex)."
               ::= { ds1 8 }

          dsx1IntervalEntry OBJECT-TYPE
               SYNTAX  Dsx1IntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Interval table."
               INDEX   { dsx1IntervalIndex, dsx1IntervalNumber }
               ::= { dsx1IntervalTable 1 }

          Dsx1IntervalEntry ::=
               SEQUENCE {
                   dsx1IntervalIndex             InterfaceIndex,
                   dsx1IntervalNumber            INTEGER,
                   dsx1IntervalESs               PerfIntervalCount,
                   dsx1IntervalSESs              PerfIntervalCount,
                   dsx1IntervalSEFSs             PerfIntervalCount,
                   dsx1IntervalUASs              PerfIntervalCount,
                   dsx1IntervalCSSs              PerfIntervalCount,
                   dsx1IntervalPCVs              PerfIntervalCount,
                   dsx1IntervalLESs              PerfIntervalCount,
                   dsx1IntervalBESs              PerfIntervalCount,
                   dsx1IntervalDMs               PerfIntervalCount,
                   dsx1IntervalLCVs              PerfIntervalCount,
                   dsx1IntervalValidData         TruthValue
          }

          dsx1IntervalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an

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                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is the same interface as identified by the
                      same value as a dsx1LineIndex object instance."
               ::= { dsx1IntervalEntry 1 }

          dsx1IntervalNumber OBJECT-TYPE
               SYNTAX  INTEGER (1..96)
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "A number between 1 and 96, where 1 is the most
                      recently completed 15 minute interval and 96 is
                      the 15 minutes interval completed 23 hours and 45
                      minutes prior to interval 1."
               ::= { dsx1IntervalEntry 2 }

          dsx1IntervalESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Errored Seconds."
               ::= { dsx1IntervalEntry 3 }

          dsx1IntervalSESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Seconds."
               ::= { dsx1IntervalEntry 4 }

          dsx1IntervalSEFSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Framing Seconds."
               ::= { dsx1IntervalEntry 5 }

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          dsx1IntervalUASs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds.  This object
                      may decrease if the occurance of unavailable
                      seconds occurs across an inteval boundary."
               ::= { dsx1IntervalEntry 6 }

          dsx1IntervalCSSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Controlled Slip Seconds."
               ::= { dsx1IntervalEntry 7 }

          dsx1IntervalPCVs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Path Coding Violations."
               ::= { dsx1IntervalEntry 8 }

          dsx1IntervalLESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Line Errored Seconds."
               ::= { dsx1IntervalEntry 9 }

          dsx1IntervalBESs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds."
               ::= { dsx1IntervalEntry 10 }

          dsx1IntervalDMs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only

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               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes."
               ::= { dsx1IntervalEntry 11 }

          dsx1IntervalLCVs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Line Code Violations."
               ::= { dsx1IntervalEntry 12 }

          dsx1IntervalValidData OBJECT-TYPE
               SYNTAX TruthValue
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "This variable indicates if the data for this
                      interval is valid."
               ::= { dsx1IntervalEntry 13 }

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          -- The DS1 Total Table
          dsx1TotalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1TotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Total Table contains the cumulative sum
                      of the various statistics for the 24 hour period
                      preceding the current interval."
               ::= { ds1 9 }

          dsx1TotalEntry OBJECT-TYPE
               SYNTAX  Dsx1TotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Total table."
               INDEX   { dsx1TotalIndex }
               ::= { dsx1TotalTable 1 }

          Dsx1TotalEntry ::=
               SEQUENCE {
                   dsx1TotalIndex                InterfaceIndex,
                   dsx1TotalESs                  PerfTotalCount,
                   dsx1TotalSESs                 PerfTotalCount,
                   dsx1TotalSEFSs                PerfTotalCount,
                   dsx1TotalUASs                 PerfTotalCount,
                   dsx1TotalCSSs                 PerfTotalCount,
                   dsx1TotalPCVs                 PerfTotalCount,
                   dsx1TotalLESs                 PerfTotalCount,
                   dsx1TotalBESs                 PerfTotalCount,
                   dsx1TotalDMs                  PerfTotalCount,
                   dsx1TotalLCVs                 PerfTotalCount
          }

          dsx1TotalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is the same interface as identified by the

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                      same value as a dsx1LineIndex object instance."
               ::= { dsx1TotalEntry 1 }

          dsx1TotalESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The sum of Errored Seconds encountered by a DS1
                      interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1TotalEntry 2 }

          dsx1TotalSESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1TotalEntry 3 }

          dsx1TotalSEFSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Severely Errored Framing Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1TotalEntry 4 }

          dsx1TotalUASs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1TotalEntry 5 }
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          dsx1TotalCSSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Controlled Slip Seconds encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1TotalEntry 6 }

          dsx1TotalPCVs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Path Coding Violations encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1TotalEntry 7 }

          dsx1TotalLESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Line Errored Seconds encountered by
                      a DS1 interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1TotalEntry 8 }

          dsx1TotalBESs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in the previous 24
                      hour interval. Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1TotalEntry 9 }

          dsx1TotalDMs OBJECT-TYPE
               SYNTAX PerfTotalCount

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               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1TotalEntry 10 }

          dsx1TotalLCVs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Line Code Violations (LCVs)
                      encountered by a DS1 interface in the current 15
                      minute interval.  Invalid 15 minute intervals
                      count as 0."
               ::= { dsx1TotalEntry 11 }

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          -- The DS1 Channel Table
          dsx1ChanMappingTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1ChanMappingEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Channel Mapping table.  This table maps a
                      DS1 channel number on a particular DS3 into an
                      ifIndex.  In the presence of DS2s, this table can
                      be used to map a DS2 channel number on a DS3 into
                      an ifIndex, or used to map a DS1 channel number on
                      a DS2 onto an ifIndex."
               ::= { ds1 16 }

          dsx1ChanMappingEntry OBJECT-TYPE
               SYNTAX  Dsx1ChanMappingEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Channel Mapping table.  There
                      is an entry in this table corresponding to each
                      ds1 ifEntry within any interface that is
                      channelized to the individual ds1 ifEntry level.

                      This table is intended to facilitate mapping from
                      channelized interface / channel number to DS1
                      ifEntry.  (e.g. mapping (DS3 ifIndex, DS1 Channel
                      Number) -> ifIndex)

                      While this table provides information that can
                      also be found in the ifStackTable and
                      dsx1ConfigTable, it provides this same information
                      with a single table lookup, rather than by walking
                      the ifStackTable to find the various constituent
                      ds1 ifTable entries, and testing various
                      dsx1ConfigTable entries to check for the entry
                      with the applicable DS1 channel number."
               INDEX   { ifIndex, dsx1Ds1ChannelNumber }
               ::= { dsx1ChanMappingTable 1 }

          Dsx1ChanMappingEntry ::=
               SEQUENCE {
                   dsx1ChanMappedIfIndex  InterfaceIndex
          }

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          dsx1ChanMappedIfIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "This object indicates the ifIndex value assigned
                      by the agent for the individual ds1 ifEntry that
                      corresponds to the given DS1 channel number
                      (specified by the INDEX element
                      dsx1Ds1ChannelNumber) of the given channelized
                      interface (specified by INDEX element ifIndex)."
               ::= { dsx1ChanMappingEntry 1 }

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          -- The DS1 Far End Current Table

          dsx1FarEndCurrentTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FarEndCurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Far End Current table contains various
                      statistics being collected for the current 15
                      minute interval.  The statistics are collected
                      from the far end messages on the Facilities Data
                      Link.  The definitions are the same as described
                      for the near-end information."
               ::= { ds1 10 }

          dsx1FarEndCurrentEntry OBJECT-TYPE
               SYNTAX  Dsx1FarEndCurrentEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Far End Current table."
               INDEX   { dsx1FarEndCurrentIndex }
               ::= { dsx1FarEndCurrentTable 1 }

          Dsx1FarEndCurrentEntry ::=
               SEQUENCE {
                   dsx1FarEndCurrentIndex      InterfaceIndex,
                   dsx1FarEndTimeElapsed       INTEGER,
                   dsx1FarEndValidIntervals    INTEGER,
                   dsx1FarEndCurrentESs        PerfCurrentCount,
                   dsx1FarEndCurrentSESs       PerfCurrentCount,
                   dsx1FarEndCurrentSEFSs      PerfCurrentCount,
                   dsx1FarEndCurrentUASs       PerfCurrentCount,
                   dsx1FarEndCurrentCSSs       PerfCurrentCount,
                   dsx1FarEndCurrentLESs       PerfCurrentCount,
                   dsx1FarEndCurrentPCVs       PerfCurrentCount,
                   dsx1FarEndCurrentBESs       PerfCurrentCount,
                   dsx1FarEndCurrentDMs        PerfCurrentCount,
                   dsx1FarEndInvalidIntervals  INTEGER
          }

          dsx1FarEndCurrentIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index

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               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is identical to the interface identified by
                      the same value of dsx1LineIndex."
               ::= { dsx1FarEndCurrentEntry 1 }

          dsx1FarEndTimeElapsed OBJECT-TYPE
               SYNTAX  INTEGER (0..899)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of seconds that have elapsed since the
                      beginning of the far end current error-measurement
                      period. If, for some reason, such as an adjustment
                      in the system's time-of-day clock, the current
                      interval exceeds the maximum value, the agent will
                      return the maximum value."
               ::= { dsx1FarEndCurrentEntry 2 }

          dsx1FarEndValidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of previous far end intervals for
                      which data was collected.  The value will be 96
                      unless the interface was brought online within the
                      last 24 hours, in which case the value will be the
                      number of complete 15 minute far end intervals
                      since the interface has been online. In the case
                      where the agent is a proxy, it is possible that
                      some intervals are unavailable.  In this case,
                      this interval is the maximum interval number for
                      which data is available."
               ::= { dsx1FarEndCurrentEntry 3 }

          dsx1FarEndCurrentESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Errored Seconds."

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               ::= { dsx1FarEndCurrentEntry 4 }

          dsx1FarEndCurrentSESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Seconds."
               ::= { dsx1FarEndCurrentEntry 5 }

          dsx1FarEndCurrentSEFSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Framing
                      Seconds."
               ::= { dsx1FarEndCurrentEntry 6 }

          dsx1FarEndCurrentUASs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds."
               ::= { dsx1FarEndCurrentEntry 7 }

          dsx1FarEndCurrentCSSs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Controlled Slip Seconds."
               ::= { dsx1FarEndCurrentEntry 8 }

          dsx1FarEndCurrentLESs OBJECT-TYPE
               SYNTAX  PerfCurrentCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Line Errored Seconds."
               ::= { dsx1FarEndCurrentEntry 9 }

          dsx1FarEndCurrentPCVs OBJECT-TYPE
               SYNTAX  PerfCurrentCount

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               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Path Coding Violations."
               ::= { dsx1FarEndCurrentEntry 10 }

          dsx1FarEndCurrentBESs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Far End Bursty Errored Seconds."
               ::= { dsx1FarEndCurrentEntry 11 }

          dsx1FarEndCurrentDMs OBJECT-TYPE
               SYNTAX PerfCurrentCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Far End Degraded Minutes."
               ::= { dsx1FarEndCurrentEntry 12 }

          dsx1FarEndInvalidIntervals OBJECT-TYPE
               SYNTAX  INTEGER (0..96)
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      " The number of intervals in the range from 0 to
                      dsx1FarEndValidIntervals for which no data is
                      available.  This object will typically be zero
                      except in cases where the data for some intervals
                      are not available (e.g., in proxy situations)."
               ::= { dsx1FarEndCurrentEntry 13 }

          -- The DS1 Far End Interval Table
          dsx1FarEndIntervalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FarEndIntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Far End Interval Table contains various
                      statistics collected by each DS1 interface over
                      the previous 24 hours of operation.  The past 24
                      hours are broken into 96 completed 15 minute
                      intervals. Each row in this table represents one

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                      such interval (identified by
                      dsx1FarEndIntervalNumber) for one specific
                      instance (identified by dsx1FarEndIntervalIndex)."
               ::= { ds1 11 }

          dsx1FarEndIntervalEntry OBJECT-TYPE
               SYNTAX  Dsx1FarEndIntervalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Far End Interval table."
               INDEX   { dsx1FarEndIntervalIndex,
                         dsx1FarEndIntervalNumber }
               ::= { dsx1FarEndIntervalTable 1 }

          Dsx1FarEndIntervalEntry ::=
               SEQUENCE {
                   dsx1FarEndIntervalIndex       InterfaceIndex,
                   dsx1FarEndIntervalNumber      INTEGER,
                   dsx1FarEndIntervalESs         PerfIntervalCount,
                   dsx1FarEndIntervalSESs        PerfIntervalCount,
                   dsx1FarEndIntervalSEFSs       PerfIntervalCount,
                   dsx1FarEndIntervalUASs        PerfIntervalCount,
                   dsx1FarEndIntervalCSSs        PerfIntervalCount,
                   dsx1FarEndIntervalLESs        PerfIntervalCount,
                   dsx1FarEndIntervalPCVs        PerfIntervalCount,
                   dsx1FarEndIntervalBESs        PerfIntervalCount,
                   dsx1FarEndIntervalDMs         PerfIntervalCount,
                   dsx1FarEndIntervalValidData   TruthValue
          }

          dsx1FarEndIntervalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is identical to the interface identified by
                      the same value of dsx1LineIndex."
               ::= { dsx1FarEndIntervalEntry 1 }

          dsx1FarEndIntervalNumber OBJECT-TYPE

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               SYNTAX  INTEGER (1..96)
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "A number between 1 and 96, where 1 is the most
                      recently completed 15 minute interval and 96 is
                      the 15 minutes interval completed 23 hours and 45
                      minutes prior to interval 1."
               ::= { dsx1FarEndIntervalEntry 2 }

          dsx1FarEndIntervalESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Errored Seconds."
               ::= { dsx1FarEndIntervalEntry 3 }

          dsx1FarEndIntervalSESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Seconds."
               ::= { dsx1FarEndIntervalEntry 4 }

          dsx1FarEndIntervalSEFSs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Framing
                      Seconds."
               ::= { dsx1FarEndIntervalEntry 5 }

          dsx1FarEndIntervalUASs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds."
               ::= { dsx1FarEndIntervalEntry 6 }

          dsx1FarEndIntervalCSSs OBJECT-TYPE

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               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Controlled Slip Seconds."
               ::= { dsx1FarEndIntervalEntry 7 }

          dsx1FarEndIntervalLESs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Line Errored Seconds."
               ::= { dsx1FarEndIntervalEntry 8 }

          dsx1FarEndIntervalPCVs OBJECT-TYPE
               SYNTAX  PerfIntervalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Path Coding Violations."
               ::= { dsx1FarEndIntervalEntry 9 }

          dsx1FarEndIntervalBESs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Far End Bursty Errored Seconds."
               ::= { dsx1FarEndIntervalEntry 10 }

          dsx1FarEndIntervalDMs OBJECT-TYPE
               SYNTAX PerfIntervalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Far End Degraded Minutes."
               ::= { dsx1FarEndIntervalEntry 11 }

          dsx1FarEndIntervalValidData OBJECT-TYPE
               SYNTAX TruthValue
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      " This variable indicates if the data for this

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                      interval is valid."
               ::= { dsx1FarEndIntervalEntry 12 }

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          -- The DS1 Far End Total Table

          dsx1FarEndTotalTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FarEndTotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "The DS1 Far End Total Table contains the
                      cumulative sum of the various statistics for the
                      24 hour period preceding the current interval."
               ::= { ds1 12 }

          dsx1FarEndTotalEntry OBJECT-TYPE
               SYNTAX  Dsx1FarEndTotalEntry
               MAX-ACCESS  not-accessible
               STATUS  current
               DESCRIPTION
                      "An entry in the DS1 Far End Total table."
               INDEX   { dsx1FarEndTotalIndex }
               ::= { dsx1FarEndTotalTable 1 }

          Dsx1FarEndTotalEntry ::=
               SEQUENCE {
                   dsx1FarEndTotalIndex          InterfaceIndex,
                   dsx1FarEndTotalESs            PerfTotalCount,
                   dsx1FarEndTotalSESs           PerfTotalCount,
                   dsx1FarEndTotalSEFSs          PerfTotalCount,
                   dsx1FarEndTotalUASs           PerfTotalCount,
                   dsx1FarEndTotalCSSs           PerfTotalCount,
                   dsx1FarEndTotalLESs           PerfTotalCount,
                   dsx1FarEndTotalPCVs           PerfTotalCount,
                   dsx1FarEndTotalBESs           PerfTotalCount,
                   dsx1FarEndTotalDMs            PerfTotalCount
          }

          dsx1FarEndTotalIndex OBJECT-TYPE
               SYNTAX  InterfaceIndex
               MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
               STATUS  current
               DESCRIPTION
                      "The index value which uniquely identifies the DS1
                      interface to which this entry is applicable.  The
                      interface identified by a particular value of this
                      index is identical to the interface identified by

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                      the same value of dsx1LineIndex."
               ::= { dsx1FarEndTotalEntry 1 }

          dsx1FarEndTotalESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Errored Seconds encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1FarEndTotalEntry 2 }

          dsx1FarEndTotalSESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 3 }

          dsx1FarEndTotalSEFSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Severely Errored Framing
                      Seconds encountered by a DS1 interface in the
                      previous 24 hour interval. Invalid 15 minute
                      intervals count as 0."
               ::= { dsx1FarEndTotalEntry 4 }

          dsx1FarEndTotalUASs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Unavailable Seconds encountered by
                      a DS1 interface in the previous 24 hour interval.
                      Invalid 15 minute intervals count as 0."
               ::= { dsx1FarEndTotalEntry 5 }

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          dsx1FarEndTotalCSSs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Controlled Slip Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 6 }

          dsx1FarEndTotalLESs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Line Errored Seconds
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 7 }

          dsx1FarEndTotalPCVs OBJECT-TYPE
               SYNTAX  PerfTotalCount
               MAX-ACCESS  read-only
               STATUS  current
               DESCRIPTION
                      "The number of Far End Path Coding Violations
                      reported via the far end block error count
                      encountered by a DS1 interface in the previous 24
                      hour interval.  Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 8 }

          dsx1FarEndTotalBESs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Bursty Errored Seconds (BESs)
                      encountered by a DS1 interface in the previous 24
                      hour interval. Invalid 15 minute intervals count
                      as 0."
               ::= { dsx1FarEndTotalEntry 9 }
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          dsx1FarEndTotalDMs OBJECT-TYPE
               SYNTAX PerfTotalCount
               MAX-ACCESS read-only
               STATUS current
               DESCRIPTION
                      "The number of Degraded Minutes (DMs) encountered
                      by a DS1 interface in the previous 24 hour
                      interval.  Invalid 15 minute intervals count as
                      0."
               ::= { dsx1FarEndTotalEntry 10 }

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          -- The DS1 Fractional Table
          dsx1FracTable OBJECT-TYPE
               SYNTAX  SEQUENCE OF Dsx1FracEntry
               MAX-ACCESS  not-accessible
               STATUS  deprecated
               DESCRIPTION
                      "This table is deprecated in favour of using
                      ifStackTable.

                      The table was mandatory for systems dividing a DS1
                      into channels containing different data streams
                      that are of local interest.  Systems which are
                      indifferent to data content, such as CSUs, need
                      not implement it.

                      The DS1 fractional table identifies which DS1
                      channels associated with a CSU are being used to
                      support a logical interface, i.e., an entry in the
                      interfaces table from the Internet-standard MIB.

                      For example, consider an application managing a
                      North American ISDN Primary Rate link whose
                      division is a 384 kbit/s H1 _B_ Channel for Video,
                      a second H1 for data to a primary routing peer,
                      and 12 64 kbit/s H0 _B_ Channels. Consider that
                      some subset of the H0 channels are used for voice
                      and the remainder are available for dynamic data
                      calls.

                      We count a total of 14 interfaces multiplexed onto
                      the DS1 interface. Six DS1 channels (for the sake
                      of the example, channels 1..6) are used for Video,
                      six more (7..11 and 13) are used for data, and the
                      remaining 12 are are in channels 12 and 14..24.

                      Let us further imagine that ifIndex 2 is of type
                      DS1 and refers to the DS1 interface, and that the
                      interfaces layered onto it are numbered 3..16.

                      We might describe the allocation of channels, in
                      the dsx1FracTable, as follows:
                    dsx1FracIfIndex.2. 1 = 3  dsx1FracIfIndex.2.13 = 4
                    dsx1FracIfIndex.2. 2 = 3  dsx1FracIfIndex.2.14 = 6
                    dsx1FracIfIndex.2. 3 = 3  dsx1FracIfIndex.2.15 = 7
                    dsx1FracIfIndex.2. 4 = 3  dsx1FracIfIndex.2.16 = 8

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                    dsx1FracIfIndex.2. 5 = 3  dsx1FracIfIndex.2.17 = 9
                    dsx1FracIfIndex.2. 6 = 3  dsx1FracIfIndex.2.18 = 10
                    dsx1FracIfIndex.2. 7 = 4  dsx1FracIfIndex.2.19 = 11
                    dsx1FracIfIndex.2. 8 = 4  dsx1FracIfIndex.2.20 = 12
                    dsx1FracIfIndex.2. 9 = 4  dsx1FracIfIndex.2.21 = 13
                    dsx1FracIfIndex.2.10 = 4  dsx1FracIfIndex.2.22 = 14
                    dsx1FracIfIndex.2.11 = 4  dsx1FracIfIndex.2.23 = 15
                    dsx1FracIfIndex.2.12 = 5  dsx1FracIfIndex.2.24 = 16

                      For North American (DS1) interfaces, there are 24
                      legal channels, numbered 1 through 24.

                      For G.704 interfaces, there are 31 legal channels,
                      numbered 1 through 31.  The channels (1..31)
                      correspond directly to the equivalently numbered
                      time-slots."
               ::= { ds1 13 }

          dsx1FracEntry OBJECT-TYPE
               SYNTAX  Dsx1FracEntry
               MAX-ACCESS  not-accessible
               STATUS  deprecated
               DESCRIPTION
                  "An entry in the DS1 Fractional table."
              INDEX   { dsx1FracIndex, dsx1FracNumber }
              ::= { dsx1FracTable 1 }

          Dsx1FracEntry ::=
              SEQUENCE {
                  dsx1FracIndex        INTEGER,
                  dsx1FracNumber       INTEGER,
                  dsx1FracIfIndex      INTEGER
              }

          dsx1FracIndex OBJECT-TYPE
              SYNTAX  INTEGER (1..'7fffffff'h)
              MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
              STATUS  deprecated
              DESCRIPTION
                 "The index value which uniquely identifies  the
                 DS1  interface  to which this entry is applicable
                 The interface identified by a  particular
                 value  of  this  index is the same interface as

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                 identified by the same value  an  dsx1LineIndex
                 object instance."
             ::= { dsx1FracEntry 1 }

          dsx1FracNumber OBJECT-TYPE
              SYNTAX  INTEGER (1..31)
              MAX-ACCESS  read-only  -- read-only since originally an
                                      -- SMIv1 index
              STATUS  deprecated
              DESCRIPTION
                 "The channel number for this entry."
             ::= { dsx1FracEntry 2 }

          dsx1FracIfIndex OBJECT-TYPE
              SYNTAX  INTEGER (0..'7fffffff'h)
              MAX-ACCESS  read-write
              STATUS  deprecated
              DESCRIPTION
                 "An index value that uniquely identifies an
                 interface.  The interface identified by a particular
                 value of this index is the same  interface
                 as  identified by the same value an ifIndex
                 object instance. If no interface is currently using
                 a channel, the value should be zero.  If a
                 single interface occupies more  than  one  time
                 slot,  that ifIndex value will be found in multiple
                 time slots."
             ::= { dsx1FracEntry 3 }

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           -- DS1 TRAPS

          ds1Traps OBJECT IDENTIFIER ::= { ds1 15 }

          dsx1LineStatusChange NOTIFICATION-TYPE
              OBJECTS { dsx1LineStatus,
                        dsx1LineStatusLastChange }
              STATUS  current
              DESCRIPTION
                      "A dsx1LineStatusChange trap is sent when the
                      value of an instance dsx1LineStatus changes. It
                      can be utilized by an NMS to trigger polls.  When
                      the line status change results from a higher level
                      line status change (i.e. ds3), then no traps for
                      the ds1 are sent."
               ::= { ds1Traps 0 1 }

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          -- conformance information
          ds1Conformance OBJECT IDENTIFIER ::= { ds1 14 }

          ds1Groups      OBJECT IDENTIFIER ::= { ds1Conformance 1 }
          ds1Compliances OBJECT IDENTIFIER ::= { ds1Conformance 2 }

          -- compliance statements

          ds1Compliance MODULE-COMPLIANCE
              STATUS  deprecated
              DESCRIPTION
                      "The compliance statement for T1 and E1
                      interfaces."
              MODULE  -- this module
                  MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                     ds1NearEndStatisticsGroup }

                  GROUP       ds1FarEndGroup
                  DESCRIPTION
                      "Implementation of this group is optional for all
                      systems that attach to a DS1 Interface."

                  GROUP       ds1NearEndOptionalConfigGroup
                  DESCRIPTION
                      "Implementation of this group is optional for all
                      systems that attach to a DS1 Interface."

                  GROUP       ds1DS2Group
                  DESCRIPTION
                      "Implementation of this group is mandatory for all
                      systems that attach to a DS2 Interface."

                  GROUP       ds1TransStatsGroup
                  DESCRIPTION
                      "This group is the set of statistics appropriate
                      for all systems which attach to a DS1 Interface
                      running transparent or unFramed lineType."

                  GROUP       ds1ChanMappingGroup
                  DESCRIPTION
                      "This group is the set of objects for mapping a
                      DS3 Channel (ds1ChannelNumber) to ifIndex.

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                      Implementation of this group is mandatory for
                      systems which support the channelization of DS3s
                      into DS1s."

                  OBJECT dsx1LineType
                           SYNTAX  INTEGER {
                                     other(1),
                                     dsx1ESF(2),
                                     dsx1D4(3),
                                     dsx1E1(4),
                                     dsx1E1CRC(5),
                                     dsx1E1MF(6),
                                     dsx1E1CRCMF(7),
                                     dsx1Unframed(8),
                                     dsx1E1Unframed(9),
                                     dsx1DS2M12(10),
                                     dsx1E2(11)
                                   }
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line type is not
                      required."

                  OBJECT dsx1LineCoding
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line coding is not
                      required."

                  OBJECT dsx1SendCode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the send code is not
                      required."

                  OBJECT dsx1LoopbackConfig
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set loopbacks is not required."

                  OBJECT dsx1SignalMode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the signal mode is not
                      required."

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                  OBJECT dsx1TransmitClockSource
                          SYNTAX  INTEGER {
                                      loopTiming(1),
                                      localTiming(2),
                                      throughTiming(3)
                                    }
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the transmit clock source is
                      not required."

                  OBJECT dsx1Fdl
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the FDL is not required."

                  OBJECT dsx1LineLength
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line length is not
                      required."

                  OBJECT dsx1Channelization
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the channelization is not
                      required."

              ::= { ds1Compliances 1 }

          ds1MibT1PriCompliance MODULE-COMPLIANCE
              STATUS deprecated
              DESCRIPTION
                      "Compliance statement for using this MIB for ISDN
                      Primary Rate interfaces on T1 lines."
              MODULE
                  MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                     ds1NearEndStatisticsGroup }
                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                          dsx1ESF(2)   -- Intl Spec would be G704(2)
                                       -- or I.431(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION

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                          "Line type for T1 ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1LineCoding
                      SYNTAX INTEGER {
                          dsx1B8ZS(2)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Type of Zero Code Suppression for
                           T1 ISDN Primary Rate interfaces."

                  OBJECT dsx1SignalMode
                      SYNTAX INTEGER {
                          none(1), -- if there is no signaling channel
                          messageOriented(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Possible signaling modes for
                           T1 ISDN Primary Rate interfaces."

                  OBJECT dsx1TransmitClockSource
                      SYNTAX INTEGER {
                          loopTiming(1)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The transmit clock is derived from
                           received clock on ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1Fdl
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Facilities Data Link usage on T1 ISDN
                           Primary Rate interfaces.
                           Note: Eventually dsx1Att-54016(4) is to be
                                 used here since the line type is ESF."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the channelization
                           is not required."

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              ::= { ds1Compliances 2 }

          ds1MibE1PriCompliance MODULE-COMPLIANCE
              STATUS deprecated
              DESCRIPTION
                      "Compliance statement for using this MIB for ISDN
                      Primary Rate interfaces on E1 lines."
              MODULE
                  MANDATORY-GROUPS { ds1NearEndConfigGroup,
                                     ds1NearEndStatisticsGroup }
                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                          dsx1E1CRC(5)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Line type for E1 ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1LineCoding
                      SYNTAX INTEGER {
                          dsx1HDB3(3)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Type of Zero Code Suppression for
                           E1 ISDN Primary Rate interfaces."

                  OBJECT dsx1SignalMode
                      SYNTAX INTEGER {
                          messageOriented(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Signaling on E1 ISDN Primary Rate interfaces
                           is always message oriented."

                  OBJECT dsx1TransmitClockSource
                      SYNTAX INTEGER {
                          loopTiming(1)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The transmit clock is derived from received

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                           clock on ISDN Primary Rate interfaces."

                  OBJECT dsx1Fdl
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Facilities Data Link usage on E1 ISDN
                           Primary Rate interfaces.
                           Note: There is a 'M-Channel' in E1,
                                 using National Bit Sa4 (G704,
                                 Table 4a). It is used to implement
                                 management features between ET
                                 and NT.  This is different to
                                 FDL in T1, which is used to carry
                                 control signals and performance
                                 data.  In E1, control and status
                                 signals are carried using National
                                 Bits Sa5, Sa6 and A (RAI Ind.).
                           This indicates that only the other(1) or
                           eventually the dsx1Fdl-none(8) bits should
                           be set in this object for E1 PRI."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                      "The ability to set the channelization is not
                      required."
              ::= { ds1Compliances 3 }

          ds1Ds2Compliance MODULE-COMPLIANCE
              STATUS current
              DESCRIPTION
                      "Compliance statement for using this MIB for DS2
                      interfaces."
              MODULE
                  MANDATORY-GROUPS { ds1DS2Group }

                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                                               dsx1DS2M12(10),
                                               dsx1E2(11)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Line type for DS2, E2

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                           interfaces."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                      "The ability to set the channelization is not
                      required."
              ::= { ds1Compliances 4 }

          ds1NCompliance MODULE-COMPLIANCE
              STATUS  current
              DESCRIPTION
                      "The compliance statement for T1 and E1
                      interfaces."
              MODULE  -- this module
                  MANDATORY-GROUPS { ds1NearEndConfigurationGroup,
                                     ds1NearEndStatisticsGroup }

                  GROUP       ds1FarEndGroup
                  DESCRIPTION
                      "Implementation of this group is optional for all
                      systems that attach to a DS1 Interface."

                  GROUP       ds1NearEndOptionalTrapGroup
                  DESCRIPTION
                      "Implementation of this group is optional for all
                      systems that attach to a DS1 Interface.  If it is
                      implemented then ds1NearEndOptionalConfigGroup
                      should also be implemented."

                  GROUP       ds1NearEndOptionalConfigGroup
                  DESCRIPTION
                      "Implementation of this group is recommended for
                      all systems that attach to a DS1 Interface and
                      implement ds1NearEndOptionalTrapGroup."

                  GROUP       ds1DS2Group
                  DESCRIPTION
                      "Implementation of this group is mandatory for all
                      systems that attach to a DS2 Interface."

                  GROUP       ds1TransStatsGroup
                  DESCRIPTION
                      "This group is the set of statistics appropriate
                      for all systems which attach to a DS1 Interface
                      running transparent or unFramed lineType."

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                  GROUP       ds1ChanMappingGroup
                  DESCRIPTION
                      "This group is the set of objects for mapping a
                      DS3 Channel (ds1ChannelNumber) to ifIndex.
                      Implementation of this group is mandatory for
                      systems which support the channelization of DS3s
                      into DS1s."

                  OBJECT dsx1LineType
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line type is not
                      required."

                  OBJECT dsx1LineCoding
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line coding is not
                      required."

                  OBJECT dsx1SendCode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the send code is not
                      required."

                  OBJECT dsx1LoopbackConfig
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set loopbacks is not required."

                  OBJECT dsx1SignalMode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the signal mode is not
                      required."

                  OBJECT dsx1TransmitClockSource
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the transmit clock source is
                      not required."

                  OBJECT dsx1Fdl
                  MIN-ACCESS read-only

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                  DESCRIPTION
                      "The ability to set the FDL is not required."

                  OBJECT dsx1LineLength
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the line length is not
                      required."

                  OBJECT dsx1Channelization
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the channelization is not
                      required."

                  OBJECT dsx1LineMode
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the Line Mode is not
                      required."

                  OBJECT dsx1LineBuildOut
                  MIN-ACCESS read-only
                  DESCRIPTION
                      "The ability to set the Line build out is not
                      required."
              ::= { ds1Compliances 5 }

          ds1MibT1PriNCompliance MODULE-COMPLIANCE
              STATUS current
              DESCRIPTION
                      "Compliance statement for using this MIB for ISDN
                      Primary Rate interfaces on T1 lines."
              MODULE
                  MANDATORY-GROUPS { ds1NearEndConfigurationGroup,
                                     ds1NearEndStatisticsGroup }

                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                          dsx1ESF(2)   -- Intl Spec would be G704(2)
                                       -- or I.431(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Line type for T1 ISDN Primary Rate

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                           interfaces."

                  OBJECT dsx1LineCoding
                      SYNTAX INTEGER {
                          dsx1B8ZS(2)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Type of Zero Code Suppression for
                           T1 ISDN Primary Rate interfaces."

                  OBJECT dsx1SignalMode
                      SYNTAX INTEGER {
                          none(1), -- if there is no signaling channel
                          messageOriented(4)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Possible signaling modes for
                           T1 ISDN Primary Rate interfaces."

                  OBJECT dsx1TransmitClockSource
                      SYNTAX INTEGER {
                          loopTiming(1)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The transmit clock is derived from
                           received clock on ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1Fdl
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Facilities Data Link usage on T1 ISDN
                           Primary Rate interfaces.
                           Note: Eventually dsx1Att-54016(4) is to be
                                 used here since the line type is ESF."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the channelization
                           is not required."
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                  OBJECT dsx1LineMode
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the Line Mode is not
                           required."

                  OBJECT dsx1LineBuildOut
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the Line build out is not
                           required."
              ::= { ds1Compliances 6 }

          ds1MibE1PriNCompliance MODULE-COMPLIANCE
              STATUS current
              DESCRIPTION
                      "Compliance statement for using this MIB for ISDN
                      Primary Rate interfaces on E1 lines."
              MODULE
                  MANDATORY-GROUPS { ds1NearEndConfigurationGroup,
                                     ds1NearEndStatisticsGroup }

                  OBJECT dsx1LineType
                      SYNTAX INTEGER {
                          dsx1E1CRC(5)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Line type for E1 ISDN Primary Rate
                           interfaces."

                  OBJECT dsx1LineCoding
                      SYNTAX INTEGER {
                          dsx1HDB3(3)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Type of Zero Code Suppression for
                           E1 ISDN Primary Rate interfaces."

                  OBJECT dsx1SignalMode
                      SYNTAX INTEGER {
                          messageOriented(4)
                      }

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                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Signaling on E1 ISDN Primary Rate interfaces
                           is always message oriented."

                  OBJECT dsx1TransmitClockSource
                      SYNTAX INTEGER {
                          loopTiming(1)
                      }
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The transmit clock is derived from received
                           clock on ISDN Primary Rate interfaces."

                  OBJECT dsx1Fdl
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "Facilities Data Link usage on E1 ISDN
                           Primary Rate interfaces.
                           Note: There is a 'M-Channel' in E1,
                                 using National Bit Sa4 (G704,
                                 Table 4a). It is used to implement
                                 management features between ET
                                 and NT.  This is different to
                                 FDL in T1, which is used to carry
                                 control signals and performance
                                 data.  In E1, control and status
                                 signals are carried using National
                                 Bits Sa5, Sa6 and A (RAI Ind.).
                           This indicates that only the other(1) or
                           eventually the dsx1Fdl-none(8) bits should
                           be set in this object for E1 PRI."

                  OBJECT dsx1Channelization
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the channelization is not
                           required."

                  OBJECT dsx1LineMode
                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the Line Mode is not required."

                  OBJECT dsx1LineBuildOut

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                      MIN-ACCESS read-only
                      DESCRIPTION
                          "The ability to set the Line build out is not
                           required."
              ::= { ds1Compliances 7 }

          -- units of conformance

          ds1NearEndConfigGroup  OBJECT-GROUP
              OBJECTS { dsx1LineIndex,
                        dsx1TimeElapsed,
                        dsx1ValidIntervals,
                        dsx1LineType,
                        dsx1LineCoding,
                        dsx1SendCode,
                        dsx1CircuitIdentifier,
                        dsx1LoopbackConfig,
                        dsx1LineStatus,
                        dsx1SignalMode,
                        dsx1TransmitClockSource,
                        dsx1Fdl,
                        dsx1InvalidIntervals,
                        dsx1LineLength,
                        dsx1LoopbackStatus,
                        dsx1Ds1ChannelNumber,
                        dsx1Channelization                      }
              STATUS  deprecated
              DESCRIPTION
                      "A collection of objects providing configuration
                      information applicable to all DS1 interfaces."
              ::= { ds1Groups 1 }

          ds1NearEndStatisticsGroup OBJECT-GROUP
              OBJECTS { dsx1CurrentIndex,
                        dsx1CurrentESs,
                        dsx1CurrentSESs,
                        dsx1CurrentSEFSs,
                        dsx1CurrentUASs,
                        dsx1CurrentCSSs,
                        dsx1CurrentPCVs,
                        dsx1CurrentLESs,
                        dsx1CurrentBESs,
                        dsx1CurrentDMs,
                        dsx1CurrentLCVs,

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                        dsx1IntervalIndex,
                        dsx1IntervalNumber,
                        dsx1IntervalESs,
                        dsx1IntervalSESs,
                        dsx1IntervalSEFSs,
                        dsx1IntervalUASs,
                        dsx1IntervalCSSs,
                        dsx1IntervalPCVs,
                        dsx1IntervalLESs,
                        dsx1IntervalBESs,
                        dsx1IntervalDMs,
                        dsx1IntervalLCVs,
                        dsx1IntervalValidData,
                        dsx1TotalIndex,
                        dsx1TotalESs,
                        dsx1TotalSESs,
                        dsx1TotalSEFSs,
                        dsx1TotalUASs,
                        dsx1TotalCSSs,
                        dsx1TotalPCVs,
                        dsx1TotalLESs,
                        dsx1TotalBESs,
                        dsx1TotalDMs,
                        dsx1TotalLCVs }
              STATUS  current
              DESCRIPTION
                      "A collection of objects providing statistics
                      information applicable to all DS1 interfaces."
              ::= { ds1Groups 2 }

          ds1FarEndGroup  OBJECT-GROUP
              OBJECTS { dsx1FarEndCurrentIndex,
                        dsx1FarEndTimeElapsed,
                        dsx1FarEndValidIntervals,
                        dsx1FarEndCurrentESs,
                        dsx1FarEndCurrentSESs,
                        dsx1FarEndCurrentSEFSs,
                        dsx1FarEndCurrentUASs,
                        dsx1FarEndCurrentCSSs,
                        dsx1FarEndCurrentLESs,
                        dsx1FarEndCurrentPCVs,
                        dsx1FarEndCurrentBESs,
                        dsx1FarEndCurrentDMs,
                        dsx1FarEndInvalidIntervals,
                        dsx1FarEndIntervalIndex,

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                        dsx1FarEndIntervalNumber,
                        dsx1FarEndIntervalESs,
                        dsx1FarEndIntervalSESs,
                        dsx1FarEndIntervalSEFSs,
                        dsx1FarEndIntervalUASs,
                        dsx1FarEndIntervalCSSs,
                        dsx1FarEndIntervalLESs,
                        dsx1FarEndIntervalPCVs,
                        dsx1FarEndIntervalBESs,
                        dsx1FarEndIntervalDMs,
                        dsx1FarEndIntervalValidData,
                        dsx1FarEndTotalIndex,
                        dsx1FarEndTotalESs,
                        dsx1FarEndTotalSESs,
                        dsx1FarEndTotalSEFSs,
                        dsx1FarEndTotalUASs,
                        dsx1FarEndTotalCSSs,
                        dsx1FarEndTotalLESs,
                        dsx1FarEndTotalPCVs,
                        dsx1FarEndTotalBESs,
                        dsx1FarEndTotalDMs }
              STATUS  current
              DESCRIPTION
                      "A collection of objects providing remote
                      configuration and statistics information."
              ::= { ds1Groups 3 }

          ds1DeprecatedGroup OBJECT-GROUP
              OBJECTS { dsx1IfIndex,
                        dsx1FracIndex,
                        dsx1FracNumber,
                        dsx1FracIfIndex }
              STATUS  deprecated
              DESCRIPTION
                      "A collection of obsolete objects that may be
                      implemented for backwards compatibility."
              ::= { ds1Groups 4 }

          ds1NearEndOptionalConfigGroup OBJECT-GROUP
              OBJECTS { dsx1LineStatusLastChange,
                        dsx1LineStatusChangeTrapEnable }

              STATUS    current
              DESCRIPTION
                      "A collection of objects that may be implemented

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                      on DS1 and DS2 interfaces."
              ::= { ds1Groups 5 }

          ds1DS2Group OBJECT-GROUP
              OBJECTS { dsx1LineIndex,
                        dsx1LineType,
                        dsx1LineCoding,
                        dsx1SendCode,
                        dsx1LineStatus,
                        dsx1SignalMode,
                        dsx1TransmitClockSource,
                        dsx1Channelization }
              STATUS   current
              DESCRIPTION
                      "A collection of objects providing information
                      about DS2 (6,312 kbps) and E2 (8,448 kbps)
                      systems."
              ::= { ds1Groups 6 }

          ds1TransStatsGroup OBJECT-GROUP
              OBJECTS { dsx1CurrentESs,
                        dsx1CurrentSESs,
                        dsx1CurrentUASs,
                        dsx1IntervalESs,
                        dsx1IntervalSESs,
                        dsx1IntervalUASs,
                        dsx1TotalESs,
                        dsx1TotalSESs,
                        dsx1TotalUASs }
              STATUS   current
              DESCRIPTION
                           "A collection of objects which are the
                      statistics which can be collected from a ds1
                      interface that is running transparent or unframed
                      lineType.  Statistics not in this list should
                      return noSuchInstance."
              ::= { ds1Groups 7 }

          ds1NearEndOptionalTrapGroup NOTIFICATION-GROUP
              NOTIFICATIONS { dsx1LineStatusChange }
              STATUS    current
              DESCRIPTION
                      "A collection of notifications that may be
                      implemented on DS1 and DS2 interfaces."
              ::= { ds1Groups 8 }

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          ds1ChanMappingGroup OBJECT-GROUP
              OBJECTS { dsx1ChanMappedIfIndex }
              STATUS    current
              DESCRIPTION
                      "A collection of objects that give an mapping of
                      DS3 Channel (ds1ChannelNumber) to ifIndex."
              ::= { ds1Groups 9 }

          ds1NearEndConfigurationGroup  OBJECT-GROUP
              OBJECTS { dsx1LineIndex,
                        dsx1TimeElapsed,
                        dsx1ValidIntervals,
                        dsx1LineType,
                        dsx1LineCoding,
                        dsx1SendCode,
                        dsx1CircuitIdentifier,
                        dsx1LoopbackConfig,
                        dsx1LineStatus,
                        dsx1SignalMode,
                        dsx1TransmitClockSource,
                        dsx1Fdl,
                        dsx1InvalidIntervals,
                        dsx1LineLength,
                        dsx1LoopbackStatus,
                        dsx1Ds1ChannelNumber,
                        dsx1Channelization,
                        dsx1LineMode,
                        dsx1LineBuildOut                      }
              STATUS  current
              DESCRIPTION
                      "A collection of objects providing configuration
                      information applicable to all DS1 interfaces."
              ::= { ds1Groups 10 }

          END

4.  Appendix A - Use of dsx1IfIndex and dsx1LineIndex

   This Appendix exists to document the previous use if dsx1IfIndex and
   dsx1LineIndex and to clarify the relationship of dsx1LineIndex as
   defined in rfc1406 with the dsx1LineIndex as defined in this
   document.

   The following shows the old and new definitions and the relationship:
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   [New Definition]: "This object should be made equal to ifIndex.  The
   next paragraph describes its previous usage.  Making the object equal
   to ifIndex allows proper use of ifStackTable and ds0/ds0bundle mibs.

   [Old Definition]: "This object is the identifier of a DS1 Interface
   on a managed device.  If there is an ifEntry that is directly
   associated with this and only this DS1 interface, it should have the
   same value as ifIndex.  Otherwise, number the dsx1LineIndices with an
   unique identifier following the rules of choosing a number that is
   greater than ifNumber and numbering the inside interfaces (e.g.,
   equipment side) with even numbers and outside interfaces (e.g,
   network side) with odd numbers."

   When the "Old Definition" was created, it was described this way to
   allow a manager to treat the value _as if_ it were and ifIndex, i.e.
   the value would either be:  1) an ifIndex value or 2) a value that
   was guaranteed to be different from all valid ifIndex values.

   The new definition is a subset of that definition, i.e., the value is
   always an ifIndex value.

   The following is Section 3.1 from RFC1406:

   Different physical configurations for the support of SNMP with DS1
   equipment exist. To accommodate these scenarios, two different
   indices for DS1 interfaces are introduced in this MIB.  These indices
   are dsx1IfIndex and dsx1LineIndex.

   External interface scenario: the SNMP Agent represents all managed
   DS1 lines as external interfaces (for example, an Agent residing on
   the device supporting DS1 interfaces directly):

   For this scenario, all interfaces are assigned an integer value equal
   to ifIndex, and the following applies:

      ifIndex=dsx1IfIndex=dsx1LineIndex for all interfaces.

   The dsx1IfIndex column of the DS1 Configuration table relates each
   DS1 interface to its corresponding interface (ifIndex) in the
   Internet-standard MIB (MIB-II STD 17, RFC1213).

   External&Internal interface scenario: the SNMP Agents resides on an
   host external from the device supporting DS1 interfaces (e.g., a
   router). The Agent represents both the host and the DS1 device.  The
   index dsx1LineIndex is used to not only represent the DS1 interfaces

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   external from the host/DS1-device combination, but also the DS1
   interfaces connecting the host and the DS1 device.  The index
   dsx1IfIndex is always equal to ifIndex.

   Example:

   A shelf full of CSUs connected to a Router. An SNMP Agent residing on
   the router proxies for itself and the CSU. The router has also an
   Ethernet interface:

         +-----+
   |     |     |
   |     |     |               +---------------------+
   |E    |     |  1.544  MBPS  |              Line#A | DS1 Link
   |t    |  R  |---------------+ - - - - -  - - -  - +------>
   |h    |     |               |                     |
   |e    |  O  |  1.544  MBPS  |              Line#B | DS1 Link
   |r    |     |---------------+ - - - - - - - - - - +------>
   |n    |  U  |               |  CSU Shelf          |
   |e    |     |  1.544  MBPS  |              Line#C | DS1 Link
   |t    |  T  |---------------+ - - - -- -- - - - - +------>
   |     |     |               |                     |
   |-----|  E  |  1.544  MBPS  |              Line#D | DS1 Link
   |     |     |---------------+ -  - - - -- - - - - +------>
   |     |  R  |               |_____________________|
   |     |     |
   |     +-----+

   The assignment of the index values could for example be:

           ifIndex (= dsx1IfIndex)                     dsx1LineIndex
                   1                   NA                  NA (Ethernet)
                   2      Line#A   Router Side             6
                   2      Line#A   Network Side            7
                   3      Line#B   Router Side             8
                   3      Line#B   Network Side            9
                   4      Line#C   Router Side            10
                   4      Line#C   Network Side           11
                   5      Line#D   Router Side            12
                   5      Line#D   Network Side           13

   For this example, ifNumber is equal to 5.  Note the following
   description of dsx1LineIndex:  the dsx1LineIndex identifies a DS1
   Interface on a managed device.  If there is an ifEntry that is

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   directly associated with this and only this DS1 interface, it should
   have the same value as ifIndex.  Otherwise, number the
   dsx1LineIndices with an unique identifier following the rules of
   choosing a number greater than ifNumber and numbering inside
   interfaces (e.g., equipment side) with even numbers and outside
   interfaces (e.g., network side) with odd numbers.

   If the CSU shelf is managed by itself by a local SNMP Agent, the
   situation would be:

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           ifIndex (= dsx1IfIndex)                      dsx1LineIndex
                   1      Line#A     Network Side            1
                   2      Line#A     RouterSide              2
                   3      Line#B     Network Side            3
                   4      Line#B     RouterSide              4
                   5      Line#C     Network Side            5
                   6      Line#C     Router Side             6
                   7      Line#D     Network Side            7
                   8      Line#D     Router Side             8

5.  Appendix B - The delay approach to Unavailable Seconds.

   This procedure is illustrated below for a DS1 ESF interface.  Similar
   rules would apply for other DS1, DS2, and E1 interface variants.  The
   procedure guarantees that the statistical counters are correctly
   updated at all times, although they lag real time by 10 seconds.  At
   the end of each 15 minutes interval the current interval counts are
   transferred to the  most recent interval entry and each interval is
   shifted up by one position, with the oldest being discarded if
   necessary in order to make room.  The current interval counts then
   start over from zero.  Note, however, that the signal state
   calculation does not start afresh at each interval boundary;  rather,
   signal state information is retained across interval boundaries.

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+---------------------------------------------------------------------+
|               READ COUNTERS & STATUS INFO FROM HARDWARE             |
|                                                                     |
| BPV EXZ LOS FE CRC CS AIS SEF OOF LOF       RAI G1-G6 SE FE LV SL   |
+---------------------------------------------------------------------+
   |   |   |   |  |   |  |   |   |   |         |    |    |  |  |  |
   |   |   |   |  |   |  |   |   |   |         |    |    |  |  |  |
   V   V   V   V  V   V  V   V   V   V         V    V    V  V  V  V
+---------------------------------------------------------------------+
|    ACCUM ONE-SEC STATS, CHK ERR THRESHOLDS, & UPDT SIGNAL STATE     |
|                                                                     |
|  |<---------- NEAR END ----------->|    |<-------- FAR END ------>| |
|                                                                     |
|  LCV LES PCV ES CSS BES SES SEFS A/U    PCV ES CSS BES SES SEFS A/U |
+---------------------------------------------------------------------+
    |   |   |  |   |   |   |   |    |      |  |   |   |   |   |    |
    |   |   |  |   |   |   |   |    |      |  |   |   |   |   |    |
    V   V   V  V   V   V   V   V    |      V  V   V   V   V   V    |
 +------------------------------+   |    +----------------------+  |
 |         ONE-SEC DELAY        |   |    |    ONE-SEC DELAY     |  |
 |           (1 OF 10)          |   |    |      (1 OF 10)       |  |
 +------------------------------+   |    +----------------------+  |
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   /   /   /  /   /   /   /   /     /      /  /   /   /   /   /    /
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   V   V   V  V   V   V   V   V     |      V  V   V   V   V   V    |
 +------------------------------+   |    +----------------------+  |
 |         ONE-SEC DELAY        |   |    |    ONE-SEC DELAY     |  |
 |           (10 OF 10)         |   |    |      (10 OF 10)      |  |
 +------------------------------+   |    +----------------------+  |
   |   |   |  |   |   |   |   |     |      |  |   |   |   |   |    |
   V   V   V  V   V   V   V   V     V      V  V   V   V   V   V    V
+---------------------------------------------------------------------+
|                    UPDATE STATISTICS COUNTERS                       |
|                                                                     |
|<-------------- NEAR END ----------->| |<--------- FAR END --------->|
|                                                                     |
|LCV LES PCV ES CSS BES SES SEFS UAS DM PCV ES CSS BES SES SEFS UAS DM|
+---------------------------------------------------------------------+

   Note that if such a procedure is adopted there is no current interval
   data for the first ten seconds after a system comes up.
   noSuchInstance must be returned if a management station attempts to
   access the current interval counters during this time.

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   It is an implementation-specific matter whether an agent assumes that
   the initial state of the interface is available or unavailable.

6.  Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   intellectual property or other rights that might be claimed to
   pertain to the implementation or use of the technology described in
   this document or the extent to which any license under such rights
   might or might not be available; neither does it represent that it
   has made any effort to identify any such rights.  Information on the
   IETF's procedures with respect to rights in standards-track and
   standards-related documentation can be found in BCP-11.  Copies of
   claims of rights made available for publication and any assurances of
   licenses to be made available, or the result of an attempt made to
   obtain a general license or permission for the use of such
   proprietary rights by implementors or users of this specification can
   be obtained from the IETF Secretariat.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights which may cover technology that may be required to practice
   this standard.  Please address the information to the IETF Executive
   Director.

7.  Full Copyright Statement

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.
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   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

8.  Acknowledgments

   This document was produced by the AToM MIB Working Group. The Editor
   would like to dedicate a special thanks to C. Mike Heard for
   providing a top notch doctor review and many helpful suggestions, and
   to acknowledge D. Fowler, Editor of RFC 2495, F. Baker and J. Watt
   Editors of RFC 1406.

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9.  References

9.1.  Normative References

[RFC2578]
     McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M.,
     and S. Waldbusser, "Structure of Management Information  Version 2
     (SMIv2)", STD 58 RFC 2578, April 1999.

[RFC2579]
     McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M.,
     and S. Waldbusser, "Textual Conventions for SMIv2", STD 58 RFC
     2579, April 1999.

[RFC2580]
     McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J., Rose, M.,
     and S. Waldbusser,"Conformance Statements for SMIv2", STD 58 RFC
     2580, April 1999.

[RFC2863]
     McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC
     2863,  June 2000.

[AT&T-TR-54016]
     AT&T Technical Reference, Requirements for Interfacing Digital
     Terminal Equipment to Services Employing the Extended Superframe
     Format, Publication 54016, May 1988.

[ANSI-T1.403]
     American National Standard for Telecommunications -- Carrier-to-
     Customer Installation - DS1 Metallic Interface, T1.403, February
     1989.

[CCITT-G.703]
     CCITT Specifications Volume III, Recommendation G.703,
     Physical/Electrical Characteristics of Hierarchical Digital
     Interfaces, April 1991.

[ITU-T-G.704]
     ITU-T G.704: Synchronous frame structures used at 1544, 6312, 2048,
     8488 and 44 736 kbit/s Hierarchical Levels, July 1995.

[ANSI-T1.231]
     American National Standard for Telecommunications -- Digital
     Hierarchy -- Layer 1 In-Service Digital Transmission Performace

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     Monitoring, T1.231, Sept 1993.

[CCITT-O.162]
     CCITT Specifications Volume IV, Recommendation O.162, Equipment To
     Perform In Service Monitoring On 2048 kbit/s Signals, July 1988.

[CCITT-G.821]
     CCITT Specifications Volume III, Recommendation G.821, Error
     Performance Of An International Digital Connection Forming Part Of
     An Integrated Services Digital Network, July 1988.

[AT&T-TR-62411]
     AT&T Technical Reference, Technical Reference 62411, ACCUNET T1.5
     Service Description And Interface Specification, December 1990.

[CCITT-G.706]
     CCITT Specifications Volume III, Recommendation G.706, Frame
     Alignment and Cyclic Redundancy Check (CRC) Procedures Relating to
     Basic Frame Structures Defined in Recommendation G.704, July 1988.

[CCITT-G.732]
     CCITT Specifications Volume III, Recommendation G.732,
     Characteristics Of Primary PCM Multiplex Equipment Operating at
     2048 kbit/s, July 1988.

[ITU-T-G.775]
     ITU-T G.775: Loss of signal (LOS) and alarm indication signal (AIS)
     defect detection and clearance criteria, May 1995.

[ITU-T-G.826]
     ITU-T G.826: Error performance parameters and objectives for
     international, constant bit rate digital paths at or above the
     primary rate, November 1993.

[ANSI-T1.107]
     American National Standard for Telecommunications -- Digital
     Hierarchy - Format Specifications, T1.107, August 1988.

[RFC3593]
     Tesink, K., "Textual Conventions for MIB Modules Using Performance
     History Based on 15 Minute Intervals", RFC 3593, September 2003.

[ITU-T-M.1400]
     ITU-T M.1400: Designation For Interconnections Among Network
     Operators, October 2001.

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9.2.  Informative References

[RFC1213]
     Rose M., Editor, "Management Information Base for Network
     Management of TCP/IP-based internets: MIB-II", RFC 1213,
     Performance Systems International, March 1991.

[RFC1406]
     F. Baker, J. Watt, "Definitions of Managed Objects for the DS1 and
     E1 Interface Types", RFC 1406, Advanced Computer Communications,
     Newbridge Networks Corporation, January 1993.

[AT&T-UM-305]
     AT&T Information Systems, AT&T ESF DS1 Channel Service Unit User's
     Manual, 999-100-305, February 1988.

[RFC2496]
     Fowler, D., "Definitions of Managed Objects for the DS3/E3
     Interface Types", RFC 2496, January 1999.
          ***********************************************************
          * NOTE TO RFC Editor (to be removed prior to publication):*
          * If <draft-ietf-atommib-rfc2496bis-05.txt> (or its       *
          * successor) is to be published as an RFC concurrently    *
          * with this document, please update this reference to     *
          * point to that RFC, instead of RFC 2496, and change      *
          * the reference tag [RFC2496] to match.                   *
          ***********************************************************

[RFC3592]
     Tesink, K., "Definitions of Managed Objects for the SONET/SDH
     Interface Type", RFC 3592, September 2003.

[RFC2494]
     Fowler, D., "Definitions of Managed Objects for the DS0 and
     DS0Bundle Interface Types", RFC 2494, January 1999.

[ANSI-T1.102]
     American National Standard for Telecommunications -- Digital
     Hierarchy - Electrical Interfaces, T1.102, December 1993.

[RFC3410]
     Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction and
     Applicability Statements for Internet-Standard Management
     Framework", RFC 3410, December 2002.

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10.  Security Considerations

   There are a number of management objects defined in this MIB module
   with a MAX-ACCESS clause of read-write.  Such objects may be
   considered sensitive or vulnerable in some network environments.  The
   support for SET operations in a non-secure environment without proper
   protection can have a negative effect on network operations.  The
   specific objects and their sensitivities/vulnerabilities are as
   follows.

   Setting the following objects to incorrect values may result in
   traffic interruptions:

      dsx1LineType
      dsx1LineCoding
      dsx1SendCode
      dsx1LoopbackConfig
      dsx1SignalMode
      dsx1TransmitClockSource
      dsx1Fdl
      dsx1LineLength
      dsx1Channelization
      dsx1LineMode
      dsx1LineBuildOut

   In the case of dsx1LineType, for example, both ends of a DS1/E1 must
   have the same value in order for traffic to flow.  In the case of
   dsx1SendCode and dsx1LoopbackConfig, for another example, traffic may
   stop transmitting when particular loopbacks are applied.

   Setting the following object to an incorrect value will not harm the
   traffic, but it may cause a circuit to be mis-identified and thereby
   create difficulties for service personnel when attempting to
   troubleshoot a problem:

      dsx1CircuitIdentifier

   Setting the following object can cause an increase in the number of
   traps received by the network management station:

      dsx1LineStatusChangeTrapEnable

   The readable objects in this MIB module (i.e., the objects with a
   MAX-ACCESS other than not-accessible) may be considered sensitive

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   in some environments since, collectively, they provide extensive
   information about the performance of interfaces in DS1/E1/DS2/E2
   equipment or networks and can reveal some aspects of their
   configuration.  In such environments it is important to control
   even GET and NOTIFY access to these objects and possibly to
   encrypt the values of these objects when sending them over the
   network via SNMP.

   SNMP versions prior to SNMPv3 did not include adequate security.
   Even if the network itself is secure (for example by using IPSec),
   even then, there is no control as to who on the secure network
   is allowed to access and GET/SET (read/change/create/delete) the
   objects in this MIB module.

   It is RECOMMENDED that implementers consider the security features
   as provided by the SNMPv3 framework (see [RFC3410], section 8),
   including full support for the SNMPv3 cryptographic mechanisms
   (for authentication and privacy).

   Further, deployment of SNMP versions prior to SNMPv3 is NOT
   RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and to
   enable cryptographic security.  It is then a customer/operator
   responsibility to ensure that the SNMP entity giving access to
   an instance of this MIB module is properly configured to give
   access to the objects only to those principals (users) that have
   legitimate rights to indeed GET or SET (change/create/delete) them.

11.  Author's Address

      Orly Nicklass (editor)
      RAD Data Communications, Ltd.
      Ziv Tower, 24 Roul Walenberg
      Tel Aviv, Israel, 69719

      Phone: 9723-765-9969

      e-Mail: orly_n@rad.com

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   Table of Contents

   1 The Internet-Standard Management Framework ...................    2
   1.1 Changes from RFC2495 .......................................    2
   1.2 Changes from RFC1406 .......................................    3
   2 Overview .....................................................    5
   2.1 Use of ifTable for DS1 Layer ...............................    5
   2.2 Usage Guidelines ...........................................    6
   2.2.1 Usage of ifStackTable for Routers and DSUs ...............    6
   2.2.2 Usage of ifStackTable for DS1/E1 on DS2/E2 ...............    8
   2.2.3 Usage of Channelization for DS3, DS1, DS0 ................    9
   2.2.4 Usage of Channelization for DS3, DS2, DS1 ................   10
   2.2.5 Usage of Loopbacks .......................................   11
   2.3 Objectives of this MIB Module ..............................   12
   2.4 DS1 Terminology ............................................   12
   2.4.1 Error Events .............................................   12
   2.4.2 Performance Defects ......................................   13
   2.4.3 Performance Parameters ...................................   14
   2.4.4 Failure States ...........................................   18
   2.4.5 Other Terms ..............................................   22
   3 Object Definitions ...........................................   23
   5.1 The DS1 Near End Group .....................................   26
   5.1.1 The DS1 Configuration Table ..............................   26
   5.1.2 The DS1 Current Table ....................................   40
   5.1.3 The DS1 Interval Table ...................................   43
   5.1.4 The DS1 Total Table ......................................   47
   5.1.5 The DS1 Channel Table ....................................   51
   5.2 The DS1 Far End Group ......................................   53
   5.2.1 The DS1 Far End Current Table ............................   53
   5.2.2 The DS1 Far End Interval Table ...........................   56
   5.2.3 The DS1 Far End Total Table ..............................   61
   5.3 The DS1 Fractional Table ...................................   65
   5.4 The DS1 Trap Group .........................................   68
   5.5 Conformance Groups .........................................   69
   4 Appendix A - Use of dsx1IfIndex and dsx1LineIndex ............   85
   5 Appendix B - The delay approach to Unavailable Seconds.  .....   89
   6 Intellectual Property ........................................   91
   7 Full Copyright Statement .....................................   91
   8 Acknowledgments ..............................................   92
   9 References ...................................................   93
   9.1 Normative References .......................................   93
   9.2 Informative References .....................................   95
   10 Security Considerations .....................................   96
   11 Author's Address ............................................   97

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