Network Working Group B. Ray Category: Internet Draft PESA Switching Systems R. Abbi Alcatel December 2002 High Capacity Textual Conventions for MIB Modules Using Performance History Based on 15 Minute Intervals draft-ietf-adslmib-hc-tc-03.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 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 (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. Expires June 30, 2003 [Page 1] INTERNET-DRAFT High Capacity TC MIB December 2002 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 .................................... 11 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 Expires June 30, 2003 [Page 2] INTERNET-DRAFT High Capacity TC MIB December 2002 the Management Information Base or MIB. Objects in the MIB are 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 Expires June 30, 2003 [Page 3] INTERNET-DRAFT High Capacity TC MIB December 2002 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. 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 "200212300000Z" -- December 30, 2002 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 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: 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 Expires June 30, 2003 [Page 4] INTERNET-DRAFT High Capacity TC MIB December 2002 history counts that require high-capacity counts." REVISION "200206160000Z" -- June 16, 2002 DESCRIPTION "Corrected addresses and references." REVISION "200209230000Z" -- September 23, 2002 DESCRIPTION "Added HCPerfValidIntervals, HCPerfInvalidIntervals, HCPerfTimeElapsed, and HCPerfIntervalThreshold." REVISION "200212300000Z" -- December 30, 2002 DESCRIPTION "Updated contact info for chair." ::= { 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 Expires June 30, 2003 [Page 5] INTERNET-DRAFT High Capacity TC MIB December 2002 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 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. Expires June 30, 2003 [Page 6] INTERNET-DRAFT High Capacity TC MIB December 2002 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 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 Expires June 30, 2003 [Page 7] INTERNET-DRAFT High Capacity TC MIB December 2002 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 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. Expires June 30, 2003 [Page 8] INTERNET-DRAFT High Capacity TC MIB December 2002 [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, 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 Expires June 30, 2003 [Page 9] INTERNET-DRAFT High Capacity TC MIB December 2002 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. [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]. Expires June 30, 2003 [Page 10] INTERNET-DRAFT High Capacity TC MIB December 2002 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 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. 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