Textual Conventions for MIB Modules Using Performance History Based on 15 Minute Intervals August 15, 1998 Kaj Tesink (editor) Bellcore kaj@cc.bellcore.com 1. Status of this Memo This document is an Internet-Draft. 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.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet- Drafts Shadow Directories on ftp.ietf.org (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). Copyright Notice Copyright (C) The Internet Society (1998). All Rights Reserved. Abstract This document defines a set of Textual Conventions for MIB modules which make use of performance history data based on 15 minute intervals. draft 15 Minute Based Performance History TCs 8/15/1998 2. Introduction When designing a MIB module, it is often useful to define new types similar to those defined in the SMI [2]. In comparison to a type defined in the SMI, each of these new types has a different name, a similar syntax, but a more precise semantics. These newly defined types are termed textual conventions, and are used for the convenience of humans reading the MIB module. This is done through Textual Conventions as defined in RFC1903[1]. It is the purpose of this document to define the set of textual conventions to be used when performance history based on 15 minute intervals is kept. See for example the Trunk MIB modules [3][4][5]. 3. Note on Invalid Data and Proxy In this document, the word proxy is meant to indicate an application which receives SNMP messages and replies to them on behalf of the devices where the actual implementation resides, e.g., DS3/E3 interfaces. The proxy will have already collected the information about the DS3/E3 interfaces into its local database and may not necessarily forward requests to the actual DS3/E3 interface. It is expected in such an application that there are periods of time where the proxy is not communicating with the DS3/E3 interfaces. In these instances the proxy will not necessarily have up-to-date configuration information and will most likely have missed the collection of some data. Missed data collection will result in invalid data in the interval table. Expires 2/15/1999 [Page 2] draft 15 Minute Based Performance History TCs 8/15/1998 4. Definitions PerfHist-TC-MIB DEFINITIONS ::= BEGIN IMPORTS MODULE-IDENTITY, Gauge32, mib-2 FROM SNMPv2-SMI TEXTUAL-CONVENTION FROM SNMPv2-TC; perfHistTCMIB MODULE-IDENTITY LAST-UPDATED "9808151100Z" ORGANIZATION "IETF AToMMIB and TrunkMIB WGs" CONTACT-INFO "Kaj Tesink Postal: Bellcore 331 Newman Springs Road Red Bank, NJ 07701 USA Tel: +1 732 758 5254 Fax: +1 732 758 2269 E-mail: kaj@cc.bellcore.com" DESCRIPTION "This MIB Module provides Textual Conventions to be used by systems supporting 15 minute based performance history counts." ::= { mib-2 xxx } -- to be filled in 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 n -- intervals of 15 minute performance data. The -- value of n is defined by the specific MIB -- module but shall be 0 < n =< 96. -- 0 The agent may optionally support performance -- data aggregating the history intervals. Expires 2/15/1999 [Page 3] draft 15 Minute Based Performance History TCs 8/15/1998 -- 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). -- Missed data collection (for whatever reason) -- will result in invalid data in the interval table. -- -- xyzTimeElapsed OBJECT-TYPE -- SYNTAX INTEGER (0..899) -- MAX-ACCESS read-only -- STATUS current -- DESCRIPTION -- "The number of seconds that have elapsed since -- the beginning of the current measurement -- period." -- ::= { xxx } -- xyzValidIntervals OBJECT-TYPE -- SYNTAX INTEGER (0..) -- -- 1 =< n =< 96 -- MAX-ACCESS read-only -- STATUS current -- DESCRIPTION -- "The number of previous near end intervals -- for which valid data was collected. The value -- will be unless the measurement was (re-)started -- within the last (*15) minutes, in which -- case the value will be the number of complete 15 -- minute intervals for which the agent has at least -- some valid 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 valid data is available." -- ::= { xxx } -- xyzInvalidIntervals OBJECT-TYPE -- SYNTAX INTEGER (0..) -- MAX-ACCESS read-only Expires 2/15/1999 [Page 4] draft 15 Minute Based Performance History TCs 8/15/1998 -- STATUS current -- DESCRIPTION -- "The number of intervals in the range from -- 0 to xyzValidIntervals for which no valid -- 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)." -- ::= { xxx } PerfCurrentCount ::= 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 (for example, a noSuchName error for SNMPv1 and a noSuchInstance for SNMPv2 GET operation)." SYNTAX Gauge32 PerfIntervalCount ::= 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 Expires 2/15/1999 [Page 5] draft 15 Minute Based Performance History TCs 8/15/1998 returned to indicate that this instance does not exist (for example, a noSuchName error for SNMPv1 and a noSuchInstance for SNMPv2 GET operation). 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." SYNTAX Gauge32 PerfTotalCount ::= 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)" SYNTAX Gauge32 END Expires 2/15/1999 [Page 6] draft 15 Minute Based Performance History TCs 8/15/1998 5. Acknowledgments This document is a product of the AToMMIB and TrunkMIB Working Groups. Expires 2/15/1999 [Page 7] draft 15 Minute Based Performance History TCs 8/15/1998 6. References [1] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Textual Conventions for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC1903, SNMP Research,Inc., Cisco Systems, Inc., Dover Beach Consulting, Inc., International Network Services, January 1996. [2] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)", RFC1902, SNMP Research,Inc., Cisco Systems, Inc., Dover Beach Consulting, Inc., International Network Services, January 1996. [3] Fowler, D., "Definitions of Managed Objects for the DS1, E1, DS2 and E2 Interface Types", RFCxxxx, Newbridge Networks, ????? 1998. [4] Fowler, D., "Definitions of Managed Objects for the DS3/E3 Interface Type", RFCxxxx, Newbridge Networks, ???? 1998. [5] Tesink, K., "Definitions of Managed Objects for the SONET/SDH Interface Type", RFCxxxx, Bellcore, ???? 1998. Expires 2/15/1999 [Page 8] draft 15 Minute Based Performance History TCs 8/15/1998 7. Security Considerations This memo defines textual conventions for use in other MIB modules. Security issues for these MIB modules are addressed in the memos defining those modules. 8. IANA Considerations Prior to publication of this memo as an RFC, IANA is requested to make a suitable OBJECT IDENTIFIER assignment and update the following line in the MIB: ::= { mib-2 xxx } -- to be filled in by IANA 9. Author's Address Kaj Tesink Bellcore 331 Newman Springs Road P.O. Box 7020 Red Bank, NJ 07701-7020 Phone: (732) 758-5254 EMail: kaj@cc.bellcore.com Expires 2/15/1999 [Page 9] draft 15 Minute Based Performance History TCs 8/15/1998 10. Full Copyright Statement Copyright (C) The Internet Society (1998). All Rights Reserved. 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Expires 2/15/1999 [Page 10] draft 15 Minute Based Performance History TCs 8/15/1998 Table of Contents 1 Status of this Memo ................................... 1 2 Introduction .......................................... 2 3 Note on Invalid Data and Proxy ........................ 2 4 Definitions ........................................... 3 5 Acknowledgments ....................................... 7 6 References ............................................ 8 7 Security Considerations ............................... 9 8 IANA Considerations ................................... 9 9 Author's Address ...................................... 9 10 Full Copyright Statement ............................. 10 Expires 2/15/1999 [Page 11]