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
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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
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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
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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
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TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
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