Network Working Group                                       L. Andersson
Internet-Draft                                                  Ericsson
Intended status: Informational BCP                                     H. van Helvoort
Expires: December 26, 2010 March 31, 2011                              Huawei Technologies
                                                               R. Bonica
                                                        Juniper Networks
                                                            D. Romascanu
                                                                   Avaya
                                                            S. Mansfield
                                                                Ericsson
                                                           June 24,
                                                      September 27, 2010

                         "The

        "Guidelines for the use of the OAM Acronym Soup"
                draft-ietf-opsawg-mpls-tp-oam-def-06.txt acronym in the IETF"
                draft-ietf-opsawg-mpls-tp-oam-def-07.txt

Abstract

   At first glance the acronym "OAM" seems to be well known and well
   understood.  Looking at the acronym a bit more closely reveals a set
   of recurring problems that are revisited time and again.

   This document provides a definition of the acronym OAM (Operations,
   Administration, and Maintenance) for use in all future IETF documents
   that refer to OAM.  In particular, it  There are other definitions and acronyms that
   will be applied in all MPLS
   Transport Profile (MPLS-TP) documents.

   This document is a product of a joint Internet Engineering Task Force
   (IETF) / International Telecommunication Union Telecommunication
   Standardization Sector (ITU-T) effort to include an MPLS Transport
   Profile within the IETF MPLS and PWE3 architectures to support discussed while exploring the
   capabilities and functionalities definition of a packet transport network.

   This Informational Internet-Draft is aimed at achieving IETF
   Consensus before publication as an RFC and will be subject to an IETF
   Last Call.

   [RFC Editor, please remove this note before publication as an RFC and
   insert the correct Streams Boilerplate to indicate that constituent
   parts of the published
   RFC has IETF Consensus.] OAM term.

Status of this Memo

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   This Internet-Draft will expire on December 26, 2010. March 31, 2011.

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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  4  3
   2.  OAM and O, A and M . . . . . . . . . . . . . . . . . . . . . .  6  5
     2.1.  OAM as a Functional Unit . . . . . . . . . . . . . . . . .  6  5
     2.2.  The Acronym Broken Up  . . . . . . . . . . . . . . . . . .  6  5
       2.2.1.  O in OAM . . . . . . . . . . . . . . . . . . . . . . .  6  5
       2.2.2.  A in OAM . . . . . . . . . . . . . . . . . . . . . . .  6  5
       2.2.3.  M in OAM . . . . . . . . . . . . . . . . . . . . . . .  7  6
   3.  Use  Recommendations on the use of the OAM Acronym in the MPLS-TP effort  . . . . . . . . .  8  7
   4.  Recommended Acronyms for the MPLS-TP effort . . . . . . . . . . . . . . . 10 . . . . . .  9
   5.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 11 10
   6.  Security Considerations  . . . . . . . . . . . . . . . . . . . 12 11
   7.  Acknowledgments  . . . . . . . . . . . . . . . . . . . . . . . 13 12
   8.  Informative references . . . . . . . . . . . . . . . . . . . . 14 13
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 14

1.  Introduction

   The main purpose of this document is to provide a definition of the
   OAM acronym such that it is useful for MPLS.  However, the
   information in this document is not specific to MPLS, so broader
   applicability of the OAM definitions provided is appropriate. IETF.

   The acronym OAM is frequently used in the data and telecommunication
   industry.  One would assume that something that is so widely used is
   very clearly defined.  However a closer look reveals some points that
   need to be clarified.

   The examples below show a number of different ways that the OAM
   acronym has been expanded in previous documents.  The examples come
   from many sources including some of the early MPLS-TP I-Ds.

   o  OAM = Operation, Administration, Maintenance

   o  OAM = Operations, Administration, Maintenance

   o  OAM = Operations, Administration, and Maintenance

   o  OAM = Operations, Administration, Management

   o  OAM = Operations and Maintenance

   o  OAM = Operations and Management

   o  O&M = Operations and Maintenance

   o  O&M = Operations and Management

   o  O&M = OAM and Management

   Sometimes there is a fourth letter added to the acronym:

   o  OAM and P = Operations, Administration, Maintenance and
      Provisioning

   If such an important piece of our technology is so poorly defined, or
   if there are dialects of the technology with different understandings
   of such a key concept, this will eventually cause problems.

   Trying to understand the use of an acronym that is as "content-rich"
   as OAM reveals two levels of complexity.  First, each letter in the
   acronym represents an integrated piece of functionality; secondly the
   acronym as such represents something that is more than just the sum
   of its parts.

   There is also the issue of how each piece of the acronym is defined.
   This document provides an analysis of how each piece of the acronym
   is defined and provides possible interpretations of the acronym.
   Finally a recommendation for the interpretation of the OAM acronym to use for the MPLS-TP
   effort based on the agreement reached in the JWT (Joint Working Team)
   report [1] is
   provided.

   Another useful document to make the OAM term understandable in a
   wider scope is found in An Overview of Operations, Administration,
   and Maintenance (OAM) Mechanisms [2].

   This document is a product of a joint Internet Engineering Task Force
   (IETF) / International Telecommunication Union Telecommunication
   Standardization Sector (ITU-T) effort to include an MPLS Transport
   Profile within the IETF MPLS and PWE3 architectures to support the
   capabilities and functionalities of a packet transport network. [I-D.ietf-opsawg-oam-overview].

2.  OAM and O, A and M

2.1.  OAM as a Functional Unit

   Operations And Maintenance (OAM): A group of network management
   functions that provide network fault indication, performance
   information, and data and diagnosis functions.  ATM OAM ITU-T I.610
   [4]
   [ITU-T I.610] is an example specification that uses this expansion of
   the OAM acronym.

   Operations, Administration, and Maintenance (OAM): A group of network
   management functions that provide network fault indication, fault
   localization, performance information, and data and diagnosis
   functions.  Examples where this acronym is used are Clause 57 of IEEE
   802.3-2008 [3] [IEEE.802.3-2008] and ITU-T Y.1731 [8]. [ITU-T Y.1731].

   The ITU-T M.3010 [7] [ITU-T M.3010] Recommendation defines operations
   systems function as a function block that processes information
   related to the telecommunications management for the purpose of monitoring/
   coordinating
   monitoring/coordinating and/or controlling telecommunication
   functions including management functions (i.e. (i.e., the TMN
   (Telecommunications Management Network) itself).

   The Metro Ethernet Forum refers to OAM as the tools and utilities to
   install, monitor and troubleshoot a network, helping carriers run
   their networks more effectively MEF 17 [9]. [MEF 17].

2.2.  The Acronym Broken Up

2.2.1.  O in OAM

   The O in the OAM acronym invariably stands for "Operations".

   However there is some ambivalence in the definition and scope of the
   term "Operation".

   Examples of tools related to "operations" are performance monitoring
   tools used for service level agreement (SLA) measurement, fault
   management tools used to monitor the health of nodes and links in the
   network, and network provisioning tools.

2.2.2.  A in OAM

   The A in the OAM acronym stands for "Administration".

   Examples of "administration" tools are network discovery and planning
   tools.

2.2.3.  M in OAM

   In the list above the M in the OAM acronym stands for "Maintenance"
   or "Management".

   Maintenance and Management may have different interpretations.
   Maintenance is defined further in Section 3, while Management is a
   broader term applicable to many functions applied to the network as
   described in Section 3.

   Since these terms have different interpretations, it is not a good
   idea to use them interchangeably.  This document defines the "M" in
   the OAM acronym to mean Maintenance.

   Examples of "maintenance" tools are implementations of connectivity
   check, loopback, link trace, and other tools that can be used to
   monitor and diagnose failures in a network or network element.

   The Recommendation ITU-T M.20 [5] [ITU-T M.20] defines maintenance as the
   whole of operations required for setting up and maintaining, within
   prescribed limits, any element involved in the setting up of a
   connection (see the ITU-T M.60 [6] [ITU-T M.60] Recommendation).  The
   purpose is to properly plan and program the maintenance operations
   required to establish and maintain a network.

   A major aim of the concept of maintenance is to minimize both the
   occurrence and the impact of failures and to ensure that in case of a
   failure the correct actions are taken.  The ITU-T documents also
   clearly define a maintenance philosophy.

3.  Use  Recommendations on the use of the OAM Acronym in the MPLS-TP effort

   In Section 4 the recommended acronyms as they will be used in the MPLS-TP effort are listed.  This section gives
   some background on the definitions provided.

   "Mgt"

   "Mgmt" will be used if an abbreviation for "Management" is needed.
   This draft does not define Management.  It is noted, however, that an
   important part of management functionality relates to tools to report
   the state of the network.

   In MPLS-TP documents, the

   The OAM acronym is to be used for "Operations, Administration, and
   Maintenance", i.e. excluding provisioning.

   OAM tools and protocols, and the "Management space" are complementary
   in nature.  Management focuses on FCAPS (Fault, Configuration,
   Accounting, Provisioning, Performance, and Security) functionality and on manager
   (or NOC (Network Operations Center)) to device (or network)
   interaction.

   From an architecture point of view OAM protocols and tools deployed
   in the data plane tend to be "horizontal", i.e., network element to
   network element.  The management protocols tend to be "vertical",
   i.e., between management stations and network elements.

   From an architecture point of view OAM protocols and tools deployed
   in the data plane tend to be "horizontal" i.e. network element to
   network element while the management protocols tend to be "vertical".

   The components of the OAM acronym (and provisioning) are defined as
   follows:

   o  Operations - Operation activities are undertaken to keep the
      network (and the services that the network provides) up and
      running.  It includes monitoring the network and finding problems.
      Ideally these problems should be found before users are affected.

   o  Administration - Administration activities involve keeping track
      of resources in the network and how they are used.  It includes
      all the bookkeeping that is necessary to track networking
      resources and the network under control.

   o  Maintenance - Maintenance activities are focused on facilitating
      repairs and upgrades - for example, when equipment must be
      replaced, when a router needs a patch for an operating system
      image, or when a new switch is added to a network.  Maintenance
      also involves corrective and preventive measures to make the
      managed network run more effectively, e.g. e.g., adjusting device
      configuration and parameters.

   "Provisioning" is outside the scope of this document, but the
   following definition is provided for completeness.

   o  Provisioning - Provisioning activities involve configuring
      resources in the network to support the offered services.  This
      might include setting up the network so that a new customer can
      receive an Internet access service.

   In general, Provisioning is used to configure the network to provide
   new services, whereas OAM is used to keep the network in a state that
   it can support already existing services.

   Sometimes it is necessary to talk about the combination of functions
   and tools supplied by OAM and Management, it is preferred that this
   is spelled out as "OAM and Management".  In cases where an acronym is
   needed O&M should be used.

4.  Recommended Acronyms for the MPLS-TP effort

   OAM - Operations, Administration, and Maintenance

   O&M - OAM and Management

   "Mgt"

   "Mgmt" - Management

5.  IANA Considerations

   This memo includes no request to IANA.

6.  Security Considerations

   This document provides guidance for the use of the OAM acronym in
   other documents.  This document does not have direct security
   implications.

   Misunderstanding of an acronym may lead to incorrect specification or
   implementation which may, in turn, open up security concerns with
   protocols or deployed networks.  Clarifying the meaning of OAM is,
   therefore, a benefit for future stability of specifications.

7.  Acknowledgments

   The following individuals significantly contributed to this document.

   o  Malcolm Betts from M. C. Betts Consulting Ltd.

   o  Kam Lam from Alcatel Lucent

   o  Dieter Beller from Alcatel Lucent

   o  David Harrington from Huawei Technologies

   Thanks to the experts of ITU-T SG 15 for their review and comments.

8.  Informative references

   [1]  Bryant, S. and L. Andersson, "Joint Working Team (JWT) Report on
        MPLS Architectural Considerations for a Transport Profile",
        RFC 5317, February 2009.

   [2]

   [I-D.ietf-opsawg-oam-overview]
              Mizrahi, T., "An Overview of Operations, Administration,
              and Maintenance (OAM) Mechanisms", draft-ietf-opsawg-oam-overview-00
              draft-ietf-opsawg-oam-overview-01 (work in progress), January
              July 2010.

   [3]

   [IEEE.802.3-2008]
              IEEE, "Information technology - Telecommunications and
              information exchange between systems - Local and
              metropolitan area networks - Specific requirements - Part
              3: Carrier sense multiple access with collision detection
              (CSMA/CD) access method and physical layer
              specifications"", IEEE Standard 802.3, December 2008.

   [4]

   [ITU-T I.610]
              International Telecommunication Union, "B-ISDN operation
              and maintenance principles and functions", ITU-T ITU-
              T Recommendation I.610, February 1999.

   [5]

   [ITU-T M.20]
              International Telecommunication Union, "Maintenance
              philosophy for telecommunication networks", ITU-T ITU-
              T Recommendation M.20, October 1992.

   [6]  International Telecommunication Union, "Maintenance terminology
        and definitions", ITU-T Recommendation M.60, March 1993.

   [7]

   [ITU-T M.3010]
              International Telecommunication Union, "Principles for a
              telecommunications management network", ITU-T ITU-
              T Recommendation M.3010, February 2000.

   [8]

   [ITU-T M.60]
              International Telecommunication Union, "Maintenance
              terminology and definitions", ITU-T Recommendation M.60,
              March 1993.

   [ITU-T Y.1731]
              International Telecommunication Union, "OAM functions and
              mechanisms for Ethernet based networks", ITU-T ITU-
              T Recommendation Y.1731, February 2008.

   [9]

   [MEF 17]   Metro Ethernet Forum, "Service OAM Requirements &
              Framework - Phase 1", MEF Technical Specification MEF 17,
              April 2007.

Authors' Addresses

   Loa Andersson
   Ericsson

   Email: loa.andersson@ericsson.com

   Huub van Helvoort
   Huawei Technologies

   Email: hhelvoort@huawei.com

   Ron Bonica
   Juniper Networks

   Email: rbonica@juniper.net

   Dan Romascanu
   Avaya

   Email: dromasca@avaya.com

   Scott Mansfield
   Ericsson

   Email: scott.mansfield@ericsson.com