    Network Working Group                                             B. Ray
    Request for Comments: 3705                        PESA Switching Systems
    Category: Standards Track                                        R. Abbi
                                                                     Alcatel
                                                               February 2004

            High Capacity Textual Conventions for MIB Modules Using
                Performance History Based on 15 Minute Intervals

    Status of this Memo

       This document specifies an Internet standards track protocol for the
       Internet community, and requests discussion and suggestions for
       improvements.  Please refer to the current edition of the "Internet
       Official Protocol Standards" (STD 1) for the standardization state
       and status of this protocol.  Distribution of this memo is unlimited.

    Copyright Notice

       Copyright (C) The Internet Society (2004).  All Rights Reserved.

    Abstract

       This document presents a set of High Capacity Textual Conventions for
       use in MIB modules which require performance history based upon 15
       minute intervals.  The Textual Conventions defined in this document
       extend the conventions presented in RFC 3593 to 64 bit resolution
       using the conventions presented in RFC 2856.

    Table of Contents

       1.  The Internet-Standard Management Framework . . . . . . . . . .  2
       2.  Overview . . . . . . . . . . . . . . . . . . . . . . . . . . .  2
       3.  Definitions. . . . . . . . . . . . . . . . . . . . . . . . . .  3
       4.  Intellectual Property Statement. . . . . . . . . . . . . . . .  8
       5.  References . . . . . . . . . . . . . . . . . . . . . . . . . .  8
           5.1.  Normative References . . . . . . . . . . . . . . . . . .  8
           5.2.  Informative References . . . . . . . . . . . . . . . . .  9
       6.  Security Considerations. . . . . . . . . . . . . . . . . . . . 10
       7.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
       8.  Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 10
       9.  Full Copyright Statement . . . . . . . . . . . . . . . . . . . 11

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    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].

       The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
       "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
       document are to be interpreted as described in [RFC2119].

    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 module that represents the managed
       equipment, including:

       -  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.

       -  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 [RFC3592], ADSL [RFC2662], HDLS2 and SHDSL
       [RFC3276] interface types.  These MIB modules use a common set of
       textual conventions defined in [RFC3593].

       A need has arisen to define 64-bit versions of the textual
       conventions in [RFC3593].  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

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       presented in [RFC2856], but that is not possible either since SMIv2
       allows only base types to be used in defining 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.

       -  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.

       Use of the textual conventions presented in this memo assumes the
       following:

       -  The agent supports 15 minute based history counters.

       -  The agent is capable of keeping a history of 96 intervals of 15
          minute performance data.

       -  The agent may optionally support performance data aggregating the
          history intervals.

       -  The agent will keep separate tables for the current interval, the
          history intervals, and the total aggregates.

    3.  Definitions

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

       IMPORTS
           MODULE-IDENTITY,
           Counter64,
           Unsigned32,
           Integer32,
           mib-2                FROM SNMPv2-SMI
           TEXTUAL-CONVENTION   FROM SNMPv2-TC;

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       hcPerfHistTCMIB MODULE-IDENTITY
          LAST-UPDATED "200402030000Z" -- February 3, 2004
          ORGANIZATION "ADSLMIB Working Group"
          CONTACT-INFO "WG-email:  adslmib@ietf.org
               Info:      https://www1.ietf.org/mailman/listinfo/adslmib

               Chair:     Mike Sneed
                          Sand Channel Systems
               Postal:    P.O.  Box 37324
                          Raleigh NC 27627-7324
                          USA
               Email:     sneedmike@hotmail.com
               Phone:     +1 206 600 7022

               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:    2301 Sugar Bush Road
                          Raleigh, NC 27612-3339
                          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.

                Copyright (C) The Internet Society (2004).  This version
                of this MIB module is part of RFC 3705: see the RFC
                itself for full legal notices."

               REVISION "200402030000Z" -- February 3, 2004
               DESCRIPTION "Initial version, published as RFC 3705."

               ::= { mib-2 107 }

       HCPerfValidIntervals ::= TEXTUAL-CONVENTION
           STATUS  current
           DESCRIPTION
              "The number of near end intervals for which data was

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              collected.  The value of an object with an
              HCPerfValidIntervals syntax will be 96 unless the
              measurement was (re-)started within the last 1440 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   Integer32 (0..96)

       HCPerfInvalidIntervals ::= TEXTUAL-CONVENTION
           STATUS  current
           DESCRIPTION
              "The number of near end intervals for which no data is
              available.  The value of an object with an
              HCPerfInvalidIntervals syntax will typically be zero except
              in cases where the data for some intervals are not available
              (e.g., in proxy situations)."
           SYNTAX   Integer32 (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 addition of a leap second, the duration of 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   Integer32 (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

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               "A gauge associated with a performance measurement in a
                current 15 minute measurement interval.  The value of an
                object with an HCPerfCurrentCount syntax 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 gauge is stored in the first 15 minute history
                interval, and the gauge 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 non-negative integer, which
                may increase or decrease, but shall never exceed 2^64-1
                (18446744073709551615 decimal), nor fall below 0.  The
                value of an object with HCPerfCurrentCount syntax
                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 object's value 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

       HCPerfIntervalCount ::= TEXTUAL-CONVENTION
           STATUS  current
           DESCRIPTION
               "A gauge 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.

                Let X be an object with HCPerfIntervalCount syntax.

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                Let Y be an object with HCPerfCurrentCount syntax.
                Let Z be an object with HCPerfTotalCount syntax.
                Then, in a system supporting a history of n intervals with
                X(1) and X(n) the most and least recent intervals
                respectively, the following applies at the end of a 15
                minute interval:

                   - discard the value of X(n)
                   - the value of X(i) becomes that of X(i-1)
                     for n >= i > 1
                   - the value of X(1) becomes that of Y.
                   - the value of Z, if supported, is adjusted.

                This count represents a non-negative integer, which
                may increase or decrease, but shall never exceed 2^64-1
                (18446744073709551615 decimal), nor fall below 0.  The
                value of an object with HCPerfIntervalCount syntax
                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 value of the 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
               "A gauge representing the aggregate of previous valid 15
                minute measurement intervals.  Intervals for which no
                valid data was available are not counted.

                This count represents a non-negative integer, which
                may increase or decrease, but shall never exceed 2^64-1
                (18446744073709551615 decimal), nor fall below 0.  The
                value of an object with HCPerfTotalCount syntax
                assumes its maximum value whenever the underlying count

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                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 object's value 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

    4. Intellectual Property Statement

       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.

    5.  References

    5.1.  Normative References

       [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
                 Requirement Levels", BCP 14, RFC 2119, March 1997.

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    RFC 3705             High Capacity Perfhist TC MIB         February 2004

       [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.

    5.2.  Informative References

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

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

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

       [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.

       [RFC3592] Tesink, K., "Definitions of Managed Objects for the
                 Synchronous Optical Network/Synchronous Digital Hierarchy
                 (SONET/SDH) Interface Type", RFC 3592, November 2003.

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

       [RFC2856] Bierman, A., McCloghrie, K.  and R. Presuhn, "Textual
                 Conventions for Additional High Capacity Data Types", RFC
                 2856, June 2000.

       [RFC3276] Ray, B. and R. Abbi, "Definitions of Managed Objects for
                 High Bit-rate DSL - 2nd Generation (HDSL2) and Single-Pair
                 High-Speed Digital Subscriber Line (SHDSL) Lines", RFC
                 3276, May 2002.

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

    6. 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 MIB
       modules that define management objects.  This document has therefore
       no impact on the security of the Internet.

    7. Acknowledgements

       This document borrows tremendously from [RFC3593] and [RFC2856].  As
       such, any credit for the text found within should be fully attributed
       to the authors of those documents.

    8. 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
       2301 Sugar Bush Road
       Raleigh, NC 27612-3339
       USA

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

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    9.  Full Copyright Statement

       Copyright (C) The Internet Society (2004).  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.

       The limited permissions granted above are perpetual and will not be
       revoked by the Internet Society or its successors or assignees.

       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.

    Acknowledgement

       Funding for the RFC Editor function is currently provided by the
       Internet Society.

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