< draft-ietf-atommib-rfc2493bis-00.txt		draft-ietf-atommib-rfc2493bis-01.txt >
			A new Request for Comments is now available in online RFC libraries.
	draft 15 Minute Based Performance History TCs 2/18/2002		RFC 3593
	Textual Conventions for MIB Modules Using Performance History
	Based on 15 Minute Intervals
	February 18, 2002
	Kaj Tesink
	Telcordia Technologies
	kaj@research.telcordia.com
	<draft-ietf-atommib-rfc2493bis-00.txt>
	1. 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 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 2/18/2002
	2. Introduction
	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. See [3][4][5] for examples. In particular, for
	this equipment it is common that history data is maintained by
	the agent in terms of fifteen minute intervals.
	This memo does not attempt to compare the relative merits of
	different strategies to obtain history data. Differences may
	include polling policy, the amount of management traffic
	between manager and agent, agent simplicity, and 'data
	currentness' of the data obtained by the manager. MIB
	designers should consider these aspects when choosing a
	particular strategy in a MIB design. Instead, this memo
	provides definitions that can be used in MIB modules that
	require history data based on fifteen minute intervals.
	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 RFC 2579 [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].
	draft 15 Minute Based Performance History TCs 2/18/2002
	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 may result in
	some intervals in the interval table being unavailable.
	4. Note on xyzTimeElapsed
	While xyzTimeElapsed is defined as having a maximum there may
	be cases (e.g., an adjustment in the system's time-of-day
	clock) where the actual value of the current interval would
	exceed this maximum value.
	Suppose that an agent which aligns its 15-minute measurement
	intervals to 15-minute time-of-day ("wall clock") boundaries
	has a time-of-day clock that systematically gains time, and
	that a manager periodically corrects the clock by setting it
	back.
	It is assumed that the agent's time-of-day clock is reasonably
	accurate, say within a few seconds per day. Thus, the
	manager's periodic clock adjustments will normally be small,
	and if done frequently enough, need not ever exceed 10
	seconds. In this case all interval durations will be within
	the allowed tolerance and none need be marked invalid, _if_
	the ANSI procedure of ending measurement intervals at 15-
	minute time-of-day boundaries is followed [6].
	If the time-of-day clock is systematically adjusted in small
	increments, then always ending measurement intervals at 15-
	minute time-of-day boundaries will result in the long term in
	the correct number of intervals with the correct average
	duration, irrespective of whether the clock is moved ahead or
	moved back. Thus, if, for some reason, such as an adjustment
	draft 15 Minute Based Performance History TCs 2/18/2002
	in the system's time-of-day clock, the current interval
	exceeds the maximum value, it is considered acceptable that
	the agent will return the maximum value.
	5. Note on xyzValidIntervals
	The overall constraint on <n> is 1 =< n =< 96. Any additional
	constraints on n must be defined in the DESCRIPTION clause
	(e.g., see [5]).
	draft 15 Minute Based Performance History TCs 2/18/2002
	6. 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 "200202180742Z"
	ORGANIZATION "IETF AToMMIB WG"
	CONTACT-INFO "AToMMIB WG:
	http://www.ietf.org/html.charters/atommib-charter.html
	Kaj Tesink
	Postal: Telcordia Technologies
	331 Newman Springs Road
	Red Bank, NJ 07701
	USA
	Tel: +1 732 758 5254
	E-mail: kaj@research.telcordia.com"
	DESCRIPTION
	"This MIB Module provides Textual Conventions
	to be used by systems supporting 15 minute
	based performance history counts."
	REVISION "200202180742Z"
	DESCRIPTION
	"Contact information and references updated.
	No technical changes have been applied."
	REVISION "9811071100Z"
	DESCRIPTION
	"The RFC2493 version of this MIB module."
	::= { mib-2 58 }
	-- The Textual Conventions defined below are organized
	-- alphabetically
	draft 15 Minute Based Performance History TCs 2/18/2002
	-- 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.
	-- 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).
	--
	-- 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.
	-- If, for some reason, such as an adjustment in the
	-- system's time-of-day clock, the current interval
	-- exceeds the maximum value, the agent will return
	-- the maximum value."
	-- ::= { xxx }
	-- xyzValidIntervals OBJECT-TYPE
	-- SYNTAX INTEGER (0..<n>)
	-- MAX-ACCESS read-only
	-- STATUS current
	-- DESCRIPTION
	-- "The number of previous near end intervals
	-- for which data was collected.
	-- [ The overall constraint on <n> is 1 =< n =< 96; ]
	-- [ Define any additional constraints on <n> here. ]
	-- The value will be <n> unless the measurement was
	-- (re-)started within the last (<n>*15) minutes, in which
	-- case the value will be the number of complete 15
	draft 15 Minute Based Performance History TCs 2/18/2002
	-- 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."
	-- ::= { xxx }
	-- xyzInvalidIntervals OBJECT-TYPE
	-- SYNTAX INTEGER (0..<n>)
	-- MAX-ACCESS read-only
	-- STATUS current
	-- DESCRIPTION
	-- "The number of intervals in the range from
	-- 0 to xyzValidIntervals 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)."
	-- ::= { 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
	draft 15 Minute Based Performance History TCs 2/18/2002
	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
	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
	draft 15 Minute Based Performance History TCs 2/18/2002
	7. Acknowledgments
	This document is a product of the AToMMIB Working Group.
	draft 15 Minute Based Performance History TCs 2/18/2002
	8. References
	[1] McCloghrie, K., Perkins, D., Schoenwaelder, J., Case, J.,
	Rose, M., and S. Waldbusser, "Textual Conventions for
	SMIv2", STD 58, RFC 2579, April 1999.
	[2] 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.
	[3] Nicklass, O., "Definitions of Managed Objects for the
	DS1, E1, DS2 and E2 Interface Types", <draft-ietf-
	atommib-rfc2495bis-00.txt>, work in progress.
	[4] Nicklass, O., "Definitions of Managed Objects for the
	DS3/E3 Interface Type", <draft-ietf-atommib-rfc2496bis-
	00.txt>, work in progress.
	[5] Tesink, K., "Definitions of Managed Objects for the
	SONET/SDH Interface Type", <draft-ietf-atommib-
	rfc2558bis-00.txt>, work in progress.
	[6] American National Standard for Telecommunications -
	Digital Hierarchy - Layer 1 In-Service Digital
	Transmission Performance Monitoring, ANSI T1.231-1997,
	September 1997.
	draft 15 Minute Based Performance History TCs 2/18/2002
	9. 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.
	10. Author's Address
	Kaj Tesink
	Telcordia Technologies
	331 Newman Springs Road
	P.O. Box 7020
	Red Bank, NJ 07701-7020
	Phone: +1 732 758 5254
	E-mail: kaj@research.telcordia.com
	draft 15 Minute Based Performance History TCs 2/18/2002		Title: Textual Conventions for MIB Modules Using
			Performance History Based on 15 Minute Intervals
			Author(s): K. Tesink, Ed.
			Status: Standards Track
			Date: September 2003
			Mailbox: kaj@research.telcordia.com
			Pages: 10
			Characters: 20363
			Obsoletes: 2493
	11. Intellectual Property		I-D Tag: draft-ietf-atommib-rfc2493bis-01.txt
	The IETF takes no position regarding the validity or scope of		URL: ftp://ftp.rfc-editor.org/in-notes/rfc3593.txt
	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		This document defines a set of Textual Conventions for MIB
	attention any copyrights, patents or patent applications, or		modules that make use of performance history data based on 15
	other proprietary rights which may cover technology that may		minute intervals.
	be required to practice this standard. Please address the
	information to the IETF Executive Director.
	draft 15 Minute Based Performance History TCs 2/18/2002		This memo replaces RFC 2493. Changes relative to RFC 2493 are
			summarized in the MIB module's REVISION clause.
	12. Full Copyright Statement		This document is a product of the AToM MIB Working Group of the IETF.
	Copyright (C) The Internet Society (2002). All Rights		This is now a Draft Standard Protocol.
	Reserved.
	This document and translations of it may be copied and		This document specifies an Internet standards track protocol for
	furnished to others, and derivative works that comment on or		the Internet community, and requests discussion and suggestions
	otherwise explain it or assist in its implementation may be		for improvements. Please refer to the current edition of the
	prepared, copied, published and distributed, in whole or in		"Internet Official Protocol Standards" (STD 1) for the
	part, without restriction of any kind, provided that the above		standardization state and status of this protocol. Distribution
	copyright notice and this paragraph are included on all such		of this memo is unlimited.
	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		This announcement is sent to the IETF list and the RFC-DIST list.
	not be revoked by the Internet Society or its successors or		Requests to be added to or deleted from the IETF distribution list
	assigns.		should be sent to IETF-REQUEST@IETF.ORG. Requests to be
			added to or deleted from the RFC-DIST distribution list should
			be sent to RFC-DIST-REQUEST@RFC-EDITOR.ORG.
	This document and the information contained herein is provided		Details on obtaining RFCs via FTP or EMAIL may be obtained by sending
	on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET		an EMAIL message to rfc-info@RFC-EDITOR.ORG with the message body
	ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR		help: ways_to_get_rfcs. For example:
	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.
	draft 15 Minute Based Performance History TCs 2/18/2002		To: rfc-info@RFC-EDITOR.ORG
			Subject: getting rfcs
	Table of Contents		help: ways_to_get_rfcs
	1 Status of this Memo ................................... 1		Requests for special distribution should be addressed to either the
	2 Introduction .......................................... 2		author of the RFC in question, or to RFC-Manager@RFC-EDITOR.ORG. Unless
	3 Note on Invalid Data and Proxy ........................ 3		specifically noted otherwise on the RFC itself, all RFCs are for
	4 Note on xyzTimeElapsed ................................ 3		unlimited distribution.echo
	5 Note on xyzValidIntervals ............................. 4		Submissions for Requests for Comments should be sent to
	6 Definitions ........................................... 5		RFC-EDITOR@RFC-EDITOR.ORG. Please consult RFC 2223, Instructions to RFC
	7 Acknowledgments ....................................... 9		Authors, for further information.
	8 References ............................................ 10
	9 Security Considerations ............................... 11
	10 Author's Address ..................................... 11
	11 Intellectual Property ................................ 12
	12 Full Copyright Statement ............................. 13
End of changes. 15 change blocks.
	431 lines changed or deleted		37 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/