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MPLS-TP Identifiers Following ITU-T Conventions

The information below is for an old version of the document.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 6923.
Authors Eric Gray , Huub van Helvoort , Malcolm Betts , Rolf Winter
Last updated 2011-10-31 (Latest revision 2011-10-28)
Replaces draft-win-mpls-tp-itu-t-identifiers
RFC stream Internet Engineering Task Force (IETF)
Additional resources Mailing list discussion
Stream WG state WG Document
Document shepherd (None)
IESG IESG state Became RFC 6923 (Proposed Standard)
Consensus boilerplate Unknown
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Network Working Group                                     R. Winter, Ed.
Internet-Draft                                                       NEC
Intended status: Standards Track                            E. Gray, Ed.
Expires: May 3, 2012                                            Ericsson
                                                         H. van Helvoort
                                           Huawei Technologies Co., Ltd.
                                                                M. Betts
                                                        October 31, 2011

            MPLS-TP Identifiers Following ITU-T Conventions


   This document specifies an extension to the identifiers to be used in
   the Transport Profile of Multiprotocol Label Switching (MPLS-TP).
   Identifiers that follow IP/MPLS conventions have already been
   defined.  This memo augments that set of identifiers for MPLS-TP
   management and OAM functions to include identifier information in a
   format typically used by the ITU-T.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at

   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."

   This Internet-Draft will expire on May 3, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   ( in effect on the date of

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   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.2.  Requirements notation . . . . . . . . . . . . . . . . . . . 4
   2.  Uniquely Identifying an Operator - the ICC_Operator_ID  . . . . 4
   3.  Use of the ICC_Operator_ID  . . . . . . . . . . . . . . . . . . 4
   4.  ICC_Operator_ID-based MEG Identifiers . . . . . . . . . . . . . 5
   5.  ICC_Operator_ID-based MEP Identifiers . . . . . . . . . . . . . 5
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 6
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . . 6
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 7

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1.  Introduction

   This document augments the initial set of identifiers to be used in
   the Transport Profile of Multiprotocol Label Switching (MPLS-TP)
   specified in RFC 6370 [RFC6370].

   RFC 6370 [RFC6370] defines a set of MPLS-TP transport and management
   entity identifiers to support bidirectional (co-routed and
   associated) point-to-point MPLS-TP LSPs, including PWs and Sections
   which follow the IP/MPLS conventions.

   This document specifies an alternative way to uniquely identify an
   operator/service provider based on ITU-T conventions and specifies
   how this operator/service provider identifier can be used to make the
   existing set of MPLS-TP transport and management entity identifiers,
   defined by RFC 6370 [RFC6370], globally unique.

   This document solely defines those identifiers.  Their use and
   possible protocols extensions to carry them is out of scope in this

   In this document, we follow the notational convention laid out in RFC
   6370 [RFC6370].

1.1.  Terminology

   CC: Country Code

   ICC: ITU-T Carrier Code

   ITU-T: International Telecommunication Union Telecommunication
   Standardization Sector

   LSP: Label Switched Path

   MEG: Maintenance Entity Group

   MEP: Maintenance Entity Group End Point

   MPLS: Multi-Protocol Label Switching

   PW: Pseudowire

   TSB: (ITU-T) Telecommunication Standardization Bureau

   UMC: Unique MEG ID Code

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1.2.  Requirements notation

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in RFC 2119 [RFC2119].

2.  Uniquely Identifying an Operator - the ICC_Operator_ID

   In RFC 6370 [RFC6370] an operator is uniquely identified by the
   Global_ID which is based on the AS number of the operator.  The ITU-T
   however traditionally identifies operators/service providers based on
   the ITU-T Carrier Code (ICC) as specified in [M1400].

   The ITU-T Telecommunication Standardization Bureau (TSB) maintains a
   list of assigned ICCs [ICC-list].  Note that ICCs can be assigned to
   both, ITU-T members as well as non-members, all of which are
   referenced at [ICC-list].  The national regulatory authorities act as
   an intermediary between the ITU/TSB and operators/service providers.
   Amongst the things that the national authorities are responsible for
   in the process of assigning an ICC is to ensure that the Carrier
   Codes are unique within their country.

   The ICC itself is a string of one to six characters, each character
   being either alphabetic (i.e.  A-Z) or numeric (i.e. 0-9).
   Alphabetic characters in the ICC SHOULD be represented with upper
   case letters.

   Global uniqueness is assured by concatenating the ICC with a Country
   Code (CC).  The Country Code (alpha-2) is a string of two alphabetic
   characters represented with upper case letters (i.e., A-Z).  The
   Country Code format is defined in ISO 3166-1 [ISO3166-1].  Together,
   the CC and the ICC form the ICC_Operator_ID as CC::ICC.

3.  Use of the ICC_Operator_ID

   The ICC_Operator_ID is used as a replacement for the Global_ID as
   specified in RFC 6370 [RFC6370], i.e. its purpose is to provide a
   globally unique context for other MPLS-TP identifiers.

   As an example, an Interface Identifier (IF_ID) in RFC 6370 [RFC6370]
   is specified as the concatenation of the Node_ID (a unique 32-bit
   value assigned by the operator) and the Interface Number (IF_Num, a
   32-bit unsigned integer assigned by the operator that is unique
   within the scope of a Node_ID).  To make this IF_ID globally unique
   the Global_ID is prefixed.  This memo specifies the ICC_Operator_ID
   as an alternative format which, just like the Global_ID, is prefixed

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   to the IF_ID.  Using the notation from RFC 6370 [RFC6370]:


   is functionally equivalent to:


   The same substitution procedure applies to all identifiers specified
   in RFC 6370 [RFC6370] except for the other alternatives mentioned in
   this document.

4.  ICC_Operator_ID-based MEG Identifiers

   The ITU-T format of MEG_IDs for MPLS-TP Sections, LSPs and
   Pseudowires is based on the globally unique ICC_Operator_ID.  In this
   case, the MEG_ID is a string of up to 15 characters.  It consists of
   three subfields: the Country Code (as described in Section 2), the
   ICC (as described in Section 2) which together form the
   ICC_Operator_ID, followed by a Unique MEG ID Code (UMC) as defined in

   The resulting MEG_ID therefore looks like the following:


   To avoid the potential for a short (i.e. less than 6 Character) ICC
   code in combination with a UMC not being unique the UMC MUST start
   with a special character that is not allowed in the ICC such as the
   "/" character.  A side effect of this is that the MEG_ID can be
   decomposed into its individual components by a receiver.

   The UMC MUST be unique within the organization identified by the
   combination of CC and ICC.

   The ICC_Operator_ID-based MEG_ID may be applied equally to a single
   MPLS-TP Section, LSP or Pseudowire.

5.  ICC_Operator_ID-based MEP Identifiers

   ICC_Operator_ID-based MEP_IDs for MPLS-TP LSPs and Pseudowires are
   formed by appending a 16-bit index to the MEG_ID defined in Section 4
   above.  Within the context of a particular MEG, we call the
   identifier associated with a MEP the MEP Index (MEP_Index).  The
   MEP_Index is administratively assigned.  It is encoded as a 16-bit
   unsigned integer and MUST be unique within the MEG.  An

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   ICC_Operator_ID-based MEP_ID is structured as:


   An ICC_Operator_ID-based MEP ID is globally unique by construction
   given the ICC_Operator_ID-based MEG_ID's global uniqueness.

6.  Security Considerations

   This document extends an existing information model and, as such,
   does in itself not introduce new security concerns.  But, as
   mentioned in the security considerations section of the document that
   is being augmented, protocol specifications that describe use of this
   information model may introduce security risks and concerns about
   authentication of participants.  For this reason, these protocol
   specifications need to describe security and authentication concerns
   that may be raised by the particular mechanisms defined and how those
   concerns may be addressed.

7.  IANA Considerations

   There are no IANA actions resulting from this document.

8.  References

8.1.  Normative References

              "Codes for the representation of names of countries and
              their subdivisions -- Part 1: Country codes", ISO 3166-1.

   [M1400]    "Designations for interconnections among operators'
              networks", ITU-T Recommendation M.1400, July 2006,

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC6370]  Bocci, M., Swallow, G., and E. Gray, "MPLS Transport
              Profile (MPLS-TP) Identifiers", RFC 6370, September 2011.

              "OAM functions and mechanisms for Ethernet based networks
              - Corrigendum 1", ITU-T Recommendation ITU-T G.8013/Y.1731
              (2011) Corrigendum 1.

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8.2.  Informative References

              "List of ITU Carrier Codes (ICCs)",

Authors' Addresses

   Rolf Winter (editor)


   Eric Gray (editor)


   Huub van Helvoort
   Huawei Technologies Co., Ltd.


   Malcolm Betts


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