wdiff draft-ietf-opsawg-mpls-tp-oam-def-03.txt draft-ietf-opsawg-mpls-tp-oam-def-04.txt

Network Working Group L. Andersson
Internet-Draft Ericsson
Intended status: Informational H. van Helvoort
Expires: August 16, November 1, 2010 Huawei Technologies
R. Bonica
Juniper Networks
D. Romascanu
Avaya
S. Mansfield
Ericsson
February 12,
April 30, 2010

"The use of the OAM Acronym Soup"
draft-ietf-opsawg-mpls-tp-oam-def-03.txt in MPLS-TP"
draft-ietf-opsawg-mpls-tp-oam-def-04.txt

Abstract

At first glance the acronym "OAM" seems to be well known and well
understood. Looking at it the acronym a bit more closely reveals a set
of recurring problems that are revisited time and again. This document
has one primary and one secondary goal. The primary goal of
this document is to find an understanding of the OAM acronym that is
useful for the MPLS Transport Profile (MPLS-TP) effort. The secondary goal is to make this understanding
applicable in a wider scope.

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.

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 the published
RFC has IETF Consensus.]

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. OAM and O, A and M . . . . . . . . . . . . . . . . . . . . . . 6
2.1. OAM as a functional unit . . . . . . . . . . . . . . . . . 6
2.2. The acronym broken up . . . . . . . . . . . . . . . . . . 6
2.2.1. O in OAM . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.2. A in OAM . . . . . . . . . . . . . . . . . . . . . . . 6
2.2.3. M in OAM . . . . . . . . . . . . . . . . . . . . . . . 7
3. Use of the OAM acronym Acronym in the MPLS-TP effort . . . . . . . . . . . . 8
4. Acronyms for the MPLS-TP effort . . . . . . . . . . . . . . . 10
5. IANA considerations . . . . . . . . . . . . . . . . . . . . . 11
6. Security considerations . . . . . . . . . . . . . . . . . . . 12
7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 13
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8.1. Normative Informative references . . . . . . . . . . . . . . . . . . . 14
8.2. Informative references . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15

1. Introduction

The state purpose of this work is very much "work in progress" and the
discussion is ongoing. The reason to publish the draft at this stage document is that some of the relevant MPLS-TP drafts are getting close to
working group last call and some provide a definition of the definitions in this document
are needed for consistency within OAM
acronym such that group of drafts. it is useful for MPLS-TP. 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 come mainly from the first set of MPLS-TP IDs. In
the IDs there were show a number of examples of how different ways that the OAM
acronym could be used expanded and there were a number understood. The examples come from
many sources including some of ways to expand and understand the
acronym e.g.: early MPLS-TP I-Ds.

o OAM = Operation, Administration, Maintenance

o OAM = Operations, Administration, 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

The examples above were taken from drafts that later were corrected

o O&M = OAM and aligned with what is proposed in this document. 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 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.

The immediate target is to

Another useful document the use of to make the OAM acronym such
that it term understandable in a
wider scope is useful for MPLS-TP. However, broader applicability of the
definitions found in this document may also come to light. An Overview of Operations, Administration,
and Maintenance (OAM) Mechanisms [2].

2. OAM and O, A and M

2.1. OAM as a functional unit

Operations and 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
[3]
[4] 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 [2] [3] and ITU-T Y.1731 [7]. [8].

The ITU-T M.3010 [6] recommendation [7] Recommendation defines operations systems
function as a function block that processes information related to
the telecommunications management for the purpose of monitoring/
coordinating and/or controlling telecommunication functions including
management functions (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 efficiently.

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 mostly stands for "Administration", though
in a few cases it seems like "Accounting" is also used. For the
purpose of this document it is assumed that "Administration" is the
correct expansion of "A".

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".

Since Maintenance and Management are defined as two different
activities it does not seem to be a good idea to use them
interchangeably. The concept behind OAM is management, so it makes
more sense to use maintenance as the expansion of the "M" in the
acronym.

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 Recommendation ITU-T M.20 [4] [5] 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 [5] recommendation). [6] 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 defines define a maintenance philosophy.

3. Use of the OAM acronym Acronym in the MPLS-TP effort

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

"Mgt" 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 drafts, documents, 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, and Security) functionality and on manager
(or NOC) 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 while the management protocols tend to be "vertical".

Where each part

The components of the OAM acronym and provisioning is (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." 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 efficiently, e.g. adjusting device
configuration and parameters.

Even though "Provisioning" is not included in this document, 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 for
providing 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. Acronyms for the MPLS-TP effort

OAM - Operations, Administration and Maintenance

O&M - Operations, Administration, Maintenance OAM and Management

"Mgt" - Management

5. IANA considerations

This memo includes no request to IANA.

6. Security considerations

Security is a significant requirement of MPLS-TP. However, this
informational document is intended only to provide guidance on the
use of the OAM acronym, and the security concerns are, therefore, out
of scope.

7. Acknowledgments

Malcolm Betts from M. C. Betts Consulting Ltd. significantly
contributed to this document.

8. References

8.1. Normative references

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

[3] 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.

[3]

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

[4]

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

[5]

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

[6]

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

[7]

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

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