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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
Ray & Abbi Standards Track [Page 1]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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 Ray & Abbi Standards Track [Page 2]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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; Ray & Abbi Standards Track [Page 3]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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 Ray & Abbi Standards Track [Page 4]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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 Ray & Abbi Standards Track [Page 5]
RFC 3705 High Capacity Perfhist TC MIB February 2004 "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. Ray & Abbi Standards Track [Page 6]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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 Ray & Abbi Standards Track [Page 7]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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. Ray & Abbi Standards Track [Page 8]
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. Ray & Abbi Standards Track [Page 9]
RFC 3705 High Capacity Perfhist TC MIB February 2004 [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 Ray & Abbi Standards Track [Page 10]
RFC 3705 High Capacity Perfhist TC MIB February 2004 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. Ray & Abbi Standards Track [Page 11]