Network Working Group                                            B. Ray
Category: Internet Draft                         PESA Switching Systems
                                                                R. Abbi
                                                                Alcatel
                                                         September 2002

         High Capacity Textual Conventions for MIB Modules Using
             Performance History Based on 15 Minute Intervals
                     draft-ietf-adslmib-hc-tc-02.txt

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
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   Internet-Drafts are draft documents valid for a maximum of six
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Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document presents a set of Textual Conventions for MIB modules
   which extends the conventions presented in RFC2493 to 64 bit
   resolution using the conventions presented in RFC2856.

















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Table of Contents

1.  The SNMP Management Framework ...................................  2
2.  Overview ........................................................  3
3.  Definitions .....................................................  4
    References ......................................................  8
    Security Considerations ......................................... 10
    IANA Considerations ............................................. 10
    Acknowledgements ................................................ 10
    Intellectual Property Notice .................................... 10
    Authors' Addresses .............................................. 11
    Full Copyright Statement ........................................ 11

1.  The SNMP Management Framework

   The SNMP Management Framework presently consists of five major
   components:

   o   An overall architecture, described in RFC 2571 [RFC2571].

   o   Mechanisms for describing and naming objects and events for the
       purpose of management. The first version of this Structure of
       Management Information (SMI) is called SMIv1 and described in STD
       16, RFC 1155 [RFC1155], STD 16, RFC 1212 [RFC1212] and RFC 1215
       [RFC1215].  The second version, called SMIv2, is described in STD
       58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58,
       RFC 2580 [RFC2580].

   o   Message protocols for transferring management information. The
       first version of the SNMP message protocol is called SNMPv1 and
       described in STD 15, RFC 1157 [RFC1157].  A second version of the
       SNMP message protocol, which is not an Internet standards track
       protocol, is called SNMPv2c and described in RFC 1901 [RFC1901]
       and RFC 1906 [RFC1906].  The third version of the message
       protocol is called SNMPv3 and described in RFC 1906 [RFC1906],
       RFC 2572 [RFC2572] and RFC 2574 [RFC2574].

   o   Protocol operations for accessing management information. The
       first set of protocol operations and associated PDU formats is
       described in STD 15, RFC 1157 [RFC1157].  A second set of
       protocol operations and associated PDU formats is described in
       RFC 1905 [RFC1905].

   o   A set of fundamental applications described in RFC 2573 [RFC2573]
       and the view-based access control mechanism described in RFC 2575
       [RFC2575].

   A more detailed introduction to the current SNMP Management Framework
   can be found in RFC 2570 [RFC2570].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  Objects in the MIB are

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   defined using the mechanisms defined in the SMI.

   This memo specifies a MIB module that is compliant to the SMIv2.  The
   textual conventions defined in this MIB module cannot be translated
   to SMIv1 since the Counter64 type does not exist in SMIv1.

2.  Overview

   In cases where a manager must obtain performance history data about
   the behavior of equipment it manages several strategies can be
   followed in the design of a MIB that represents the managed
   equipment, including:

   0    The agent counts events on a continuous basis and,
        whenever desired, the manager obtains the value of the event
        counter and adjusts its understanding of the history of events
        at the agent.

   0    The agent allocates events to 'buckets' where each bucket
        represents an interval of time.

   Telecommunications equipment often makes use of the latter strategy.
   For such equipment the standard practice is that history data is
   maintained by the agent in terms of 15-minute intervals [T1.231].

   MIB modules for collecting performance history based on 15-minute
   intervals have been defined for the DS1/E1 [RFC2495], DS3/E3
   [RFC2496], SONET/SDH [RFC2558], and ADSL [RFC2622] interface types.
   These MIB modules use a common set of textual conventions defined in
   [RFC2493].  Those textual conventions are based on the Gauge32
   data type.

   A need has arisen in connection with recent work on a VDSL MIB
   [VDSL-MIB] to define 64-bit versions of the textual conventions
   in [RFC2493].  Ideally, these high-capacity textual conventions would
   be based on a Gauge64 or Unsigned64 data type, but unfortunately no
   such types exist in SMIv2.  The next best choice would be to base
   them on the CounterBasedGauge64 textual convention presented in
   [RFC2856], but that is not possible either since SMIv2 allows only
   base types to be used textual conventions.  Therefore the textual
   conventions presented in this memo are based directly on the
   Counter64 type, like those in [RFC2856].  They are subject to the
   following limitations:

   -  The MAX-ACCESS of objects defined using these textual conventions
      must be read-only, because the MAX-ACCESS of the underlying
      Counter64 type is read-only.

   -  No sub-range can be specified in object definitions using these
      textual conventions, because sub-ranges are not allowed on
      Counter64 objects.


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   -  No DEFVAL clause can be specified in object definitions using
      these textual conventions, because DEFVALs are not allowed on
      Counter64 objects.

   -  Objects defined using these textual conventions cannot be used
      in an INDEX clause, because there is no INDEX clause mapping
      defined for objects of type Counter64.

3.  Definitions

    HC-PerfHist-TC-MIB DEFINITIONS ::= BEGIN

    IMPORTS
        MODULE-IDENTITY,
        Counter64,
        Unsigned32,
        mib-2                FROM SNMPv2-SMI
        TEXTUAL-CONVENTION   FROM SNMPv2-TC;

    hcPerfHistTCMIB MODULE-IDENTITY
       LAST-UPDATED "200206160000Z" -- June 16, 2002
       ORGANIZATION "ADSLMIB Working Group"
       CONTACT-INFO "WG-email:  adslmib@ietf.org
                  Info:      https://www1.ietf.org/mailman/listinfo/adslmib

                  Chair:     Mike Sneed
                  Postal:    P.O. Box 37324
                             Raleigh NC 27627-7324
                  Email:     sneedmike@hotmail.com

                  Co-editor: Bob Ray
                             PESA Switching Systems, Inc.
                  Postal:    330-A Wynn Drive
                             Huntsville, AL 35805 USA
                  Email:     rray@pesa.com
                  Phone:     +1 256 726 9200 ext. 142

                  Co-editor: Rajesh Abbi
                             Alcatel USA
                  Postal:    2912 Wake Forest Road
                             Raleigh, NC 27609-7860 USA
                  Email:     Rajesh.Abbi@alcatel.com
                  Phone:     +1 919 850 6194
            "
        DESCRIPTION
            "This MIB Module provides Textual Conventions to be
             used by systems supporting 15 minute based performance
             history counts that require high-capacity counts."

        REVISION "200206160000Z" -- June 16, 2002
        DESCRIPTION "Corrected addresses and references."

        REVISION "200209230000Z" -- September 23, 2002

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        DESCRIPTION "Added HCPerfValidIntervals, HCPerfInvalidIntervals,
             HCPerfTimeElapsed, and HCPerfIntervalThreshold."

        ::= { mib-2 xxx }  -- to be assigned by IANA

    -- The Textual Conventions defined below are organized
    -- alphabetically
    -- Use of these TCs assumes the following:
    -- 0  The agent supports 15 minute based history
    --    counters.
    -- 0  The agent is capable of keeping a history of 96
    --    intervals of 15 minute performance data.
    -- 0  The agent may optionally support performance
    --    data aggregating the history intervals.
    -- 0  The agent will keep separate tables for the
    --    current interval, the history intervals, and
    --    the total aggregates.
    -- 0  The agent will keep the following objects.
    --    If performance data is kept for multiple instances
    --    of a measured entity, then
    --    these objects are applied to each instance of
    --    the measured entity (e.g., interfaces).

    HCPerfValidIntervals ::= TEXTUAL-CONVENTION
        STATUS  current
        DESCRIPTION
           "The number of previous near end intervals for which
           data was collected.  The value will be 96 unless the
           measurement was (re-)started within the last 900 minutes,
           in which case the value will be the number of complete 15
           minute intervals for which the agent has at least some
           data. In certain cases (e.g., 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."
        SYNTAX   INTEGER (0..96)

    HCPerfInvalidIntervals ::= TEXTUAL-CONVENTION
        STATUS  current
        DESCRIPTION
           "The number of previous intervals 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)."
        SYNTAX   INTEGER (0..96)

    HCPerfTimeElapsed ::= TEXTUAL-CONVENTION
        STATUS  current
        DESCRIPTION
           "The number of seconds that have elapsed since the beginning
           of the current measurement period.  If, for some reason, such
           as an adjustment in the system's time-of-day clock or the

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           addition of a leap second, the current interval exceeds the
           maximum value, the agent will return the maximum value.

           For 15 minute intervals, the range is limited to (0..899).
           For 24 hour intervals, the range is limited to (0..86399)."
        SYNTAX   Unsigned32 (0..86399)

    HCPerfIntervalThreshold ::= TEXTUAL-CONVENTION
        STATUS   current
        DESCRIPTION
            "This convention defines a range of values that may be set
            in a fault threshold alarm control.  As the number of seconds
            in a 15-minute interval numbers at most 900, objects of this
            type may have a range of 0...900, where the value of 0 disables
            the alarm."
        SYNTAX   Unsigned32 (0..900)

    HCPerfCurrentCount ::= TEXTUAL-CONVENTION
        STATUS  current
        DESCRIPTION
            "A counter associated with a performance measurement in a
             current 15 minute measurement interval. The value of this
             counter starts from zero and is increased when associated
             events occur, until the end of the 15 minute interval.
             At that time the value of the counter is stored in the
             first 15 minute history interval, and the CurrentCount is
             restarted at zero. In the case where the agent has no valid
             data available for the current interval the corresponding
             object instance is not available and upon a retrieval
             request a corresponding error message shall be returned to
             indicate that this instance does not exist.

             This count represents a a non-negative integer, which
             may increase or decrease, but shall never exceed 2^64-1
             (18446744073709551615 decimal), nor fall below 0.  The
             The value of a HCPerfCurrentCount object assumes its
             maximum value whenever the underlying count exceeds
             2^64-1.  If the underlying count subsequently decreases
             below 2^64-1 (due, e.g., to a retroactive adjustment as a
             result of entering or exiting unavailable time), then the
             HCPerfCurrentCount object also decreases.

             Note that this TC is not strictly supported in SMIv2,
             because the 'always increasing' and 'counter wrap'
             semantics associated with the Counter64 base type are not
             preserved.  It is possible that management applications
             which rely solely upon the (Counter64) ASN.1 tag to
             determine object semantics will mistakenly operate upon
             objects of this type as they would for Counter64 objects.

             This textual convention represents a limited and short-term
             solution, and may be deprecated as a long term solution is

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             defined and deployed to replace it."
        SYNTAX  Counter64

    HCPerfIntervalCount ::= TEXTUAL-CONVENTION
        STATUS  current
        DESCRIPTION
            "A counter associated with a performance measurement in
             a previous 15 minute measurement interval. In the case
             where the agent has no valid data available for a
             particular interval the corresponding object instance is
             not available and upon a retrieval request a corresponding
             error message shall be returned to indicate that this
             instance does not exist.

             In a system supporting a history of n intervals with
             IntervalCount(1) and IntervalCount(n) the most and least
             recent intervals respectively, the following applies at
             the end of a 15 minute interval:

                - discard the value of IntervalCount(n)
                - the value of IntervalCount(i) becomes that
                    of IntervalCount(i-1) for n >= i > 1
                - the value of IntervalCount(1) becomes that
                    of CurrentCount
                - the TotalCount, if supported, is adjusted.

             This count represents a a non-negative integer, which
             may increase or decrease, but shall never exceed 2^64-1
             (18446744073709551615 decimal), nor fall below 0.  The
             The value of a HCPerfIntervalCount object assumes its
             maximum value whenever the underlying count exceeds
             2^64-1.  If the underlying count subsequently decreases
             below 2^64-1 (due, e.g., to a retroactive adjustment as a
             result of entering or exiting unavailable time), then the
             HCPerfIntervalCount object also decreases.

             Note that this TC is not strictly supported in SMIv2,
             because the 'always increasing' and 'counter wrap'
             semantics associated with the Counter64 base type are not
             preserved.  It is possible that management applications
             which rely solely upon the (Counter64) ASN.1 tag to
             determine object semantics will mistakenly operate upon
             objects of this type as they would for Counter64 objects.

             This textual convention represents a limited and short-term
             solution, and may be deprecated as a long term solution is
             defined and deployed to replace it."
        SYNTAX  Counter64

    HCPerfTotalCount ::= TEXTUAL-CONVENTION
        STATUS  current
        DESCRIPTION

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            "A counter associated with a performance measurements
             aggregating the previous valid 15 minute measurement
             intervals. Intervals for which no valid data was
             available are not counted.

             This count represents a a non-negative integer, which
             may increase or decrease, but shall never exceed 2^64-1
             (18446744073709551615 decimal), nor fall below 0.  The
             The value of a HCPerfTotalCount object assumes its
             maximum value whenever the underlying count exceeds
             2^64-1.  If the underlying count subsequently decreases
             below 2^64-1 (due, e.g., to a retroactive adjustment as a
             result of entering or exiting unavailable time), then the
             HCPerfTotalCount object also decreases.

             Note that this TC is not strictly supported in SMIv2,
             because the 'always increasing' and 'counter wrap'
             semantics associated with the Counter64 base type are not
             preserved.  It is possible that management applications
             which rely solely upon the (Counter64) ASN.1 tag to
             determine object semantics will mistakenly operate upon
             objects of this type as they would for Counter64 objects.

             This textual convention represents a limited and short-term
             solution, and may be deprecated as a long term solution is
             defined and deployed to replace it."
        SYNTAX  Counter64
    END

Informative References

   [T1.231]    American National Standard for Telecommunications -
               Digital Hierarchy - Layer 1 In-Service Digital
               Transmission Performance Monitoring, ANSI T1.231-1997,
               September 1997.

   [RFC1155]   Rose, M. and K. McCloghrie, "Structure and Identification
               of Management Information for TCP/IP-based Internets",
               STD 16, RFC 1155, May 1990.

   [RFC1157]   Case, J., Fedor, M., Schoffstall, M. and J. Davin,
               "Simple Network Management Protocol", STD 15, RFC 1157,
               May 1990.

   [RFC1212]   Rose, M. and K. McCloghrie, "Concise MIB Definitions",
               STD 16, RFC 1212, March 1991.

   [RFC1215]   Rose, M., "A Convention for Defining Traps for use with
               the SNMP", RFC 1215, March 1991.

   [RFC1901]   Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
               "Introduction to Community-based SNMPv2", RFC 1901,

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               January 1996.

   [RFC1905]   Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
               "Protocol Operations for Version 2 of the Simple Network
               Management Protocol (SNMPv2)", RFC 1905, January 1996.

   [RFC1906]   Case, J., McCloghrie, K., Rose, M. and S. Waldbusser,
               "Transport Mappings for Version 2 of the Simple Network
               Management Protocol (SNMPv2)", RFC 1906, January 1996.

   [RFC2026]   Bradner, S., "The Internet Standards Process -- Revision
               3", BCP 9, RFC 2026, October 1996.

   [RFC2493]   Tesink, K., "Textual Conventions for MIB Modules Using
               Performance History Based on 15 Minute Intervals", RFC
               2493, January 1999.

   [RFC2495]   Fowler, D., "Definitions of Managed Objects for the DS1,
               E1, DS2 and E2 Interface Types", RFC 2495, January 1999.

   [RFC2496]   Fowler, D., "Definitions of Managed Objects for the
               DS3/E3 Interface Type", RFC 2496, January 1999.

   [RFC2558]   Tesink, K., "Definitions of Managed Objects for the
               SONET/SDH Interface Type", RFC 2558, March 1999.

   [RFC2662]   Bathrick, G. and F. Ly, "Definitions of Managed Objects
               for the ADSL Lines", RFC 2662, August 1999.

   [RFC2570]   Case, J., Mundy, R., Partain, D. and B. Stewart,
               "Introduction to Version 3 of the Internet-standard
               Network Management Framework", RFC 2570, April 1999.

   [RFC2571]   Harrington, D., Presuhn, R. and B. Wijnen, "An
               Architecture for Describing SNMP Management Frameworks",
               RFC 2571, April 1999.

   [RFC2572]   Case, J., Harrington D., Presuhn R. and B. Wijnen,
               "Message Processing and Dispatching for the Simple
               Network Management Protocol (SNMP)", RFC 2572, April
               1999.

   [RFC2573]   Levi, D., Meyer, P. and B. Stewart, "SNMPv3
               Applications", RFC 2573, April 1999.

   [RFC2574]   Blumenthal, U. and B. Wijnen, "User-based Security Model
               (USM) for version 3 of the Simple Network Management
               Protocol (SNMPv3)", RFC 2574, April 1999.

   [RFC2575]   Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based
               Access Control Model (VACM) for the Simple Network
               Management Protocol (SNMP)", RFC 2575, April 1999.

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   [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.

   [RFC2856]   Bierman, A., McCloghrie, K. and R. Presuhn, "Textual
               Conventions for Additional High Capacity Data Types",
               RFC2856, June 2000.

   [VDSL-MIB]  Ray, B. and R. Abbi, work in progress.


Security Considerations

   This module does not define any management objects. Instead, it
   defines a set of textual conventions which may be used by other MIB
   modules to define management objects.

   Meaningful security considerations can only be written in the modules
   that define management objects.

IANA Considerations

   Prior to publication of this memo as an RFC, IANA is requested to
   make a suitable OBJECT IDENTIFIER assignment.

Acknowledgements

   This document borrows tremendously from [RFC2493] and [RFC2856].
   As such, any credit for the text found within should be fully
   attributed to the authors of those documents.

Intellectual Property Notice

   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

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   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.

Authors' Addresses

   Bob Ray
   PESA Switching Systems, Inc.
   330-A Wynn Drive
   Huntsville, AL 35805 USA

   Phone: +1 256 726 9200 ext. 142
   Fax: +1 256 726 9271
   EMail: rray@pesa.com

   Rajesh Abbi
   Alcatel USA
   2912 Wake Forest Road
   Raleigh, NC 27609-7860 USA

   Phone: +1 919 850 6194
   EMail: Rajesh.Abbi@alcatel.com

Full Copyright Statement

   Copyright (C) The Internet Society (2002).  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
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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

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   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.

















































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