draft-ietf-mpls-tp-identifiers-02.txt   draft-ietf-mpls-tp-identifiers-03.txt 
MPLS Working Group M. Bocci MPLS Working Group M. Bocci
Internet-Draft Alcatel-Lucent Internet-Draft Alcatel-Lucent
Intended status: Standards Track G. Swallow Intended status: Standards Track G. Swallow
Expires: January 13, 2011 Cisco Expires: April 28, 2011 Cisco
July 12, 2010 E. Gray
Ericsson
October 25, 2010
MPLS-TP Identifiers MPLS-TP Identifiers
draft-ietf-mpls-tp-identifiers-02 draft-ietf-mpls-tp-identifiers-03
Abstract Abstract
This document specifies identifiers for MPLS-TP objects. Included This document specifies identifiers for MPLS-TP objects. Included
are identifiers conformant to existing ITU conventions and are identifiers conformant to existing ITU conventions and
identifiers which are compatible with existing IP, MPLS, GMPLS, and identifiers which are compatible with existing IP, MPLS, GMPLS, and
Pseudowire definitions. Pseudowire definitions.
Status of this Memo Status of this Memo
skipping to change at page 1, line 34 skipping to change at page 1, line 36
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 13, 2011. This Internet-Draft will expire on April 28, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.3. Notational Conventions in Backus-Naur Form . . . . . . . . 4
2. Named Entities . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Named Entities . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Uniquely Identifying an Operator . . . . . . . . . . . . . . . 5 3. Uniquely Identifying an Operator . . . . . . . . . . . . . . . 5
3.1. The Global ID . . . . . . . . . . . . . . . . . . . . . . 5 3.1. The Global ID . . . . . . . . . . . . . . . . . . . . . . 5
3.2. ITU Carrier Code . . . . . . . . . . . . . . . . . . . . . 5 3.2. ITU Carrier Code . . . . . . . . . . . . . . . . . . . . . 6
4. Node and Interface Identifiers . . . . . . . . . . . . . . . . 6 4. Node and Interface Identifiers . . . . . . . . . . . . . . . . 6
5. MPLS-TP Tunnel and LSP Identifiers . . . . . . . . . . . . . . 7 5. MPLS-TP Tunnel and LSP Identifiers . . . . . . . . . . . . . . 7
5.1. MPLS-TP Point to Point Tunnel Identifiers . . . . . . . . 7 5.1. MPLS-TP Point to Point Tunnel Identifiers . . . . . . . . 8
5.2. MPLS-TP LSP Identifiers . . . . . . . . . . . . . . . . . 8 5.2. MPLS-TP LSP Identifiers . . . . . . . . . . . . . . . . . 8
5.3. Mapping to GMPLS Signalling . . . . . . . . . . . . . . . 8 5.3. Mapping to GMPLS Signalling . . . . . . . . . . . . . . . 9
6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 9 6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 9
7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 9 7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 10
7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 10 7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 10
7.1.1. ICC based MEG_IDs . . . . . . . . . . . . . . . . . . 10 7.1.1. ICC-based MEG Identifiers . . . . . . . . . . . . . . 10
7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 10 7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 11
7.1.2.1. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 10 7.1.2.1. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 11
7.1.2.2. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 10 7.1.2.2. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 11
7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.2.1. ICC based MEP_IDs . . . . . . . . . . . . . . . . . . 11 7.2.1. ICC-based MEP Identifiers . . . . . . . . . . . . . . 11
7.2.2. IP based MEP_IDs . . . . . . . . . . . . . . . . . . . 11 7.2.2. IP based MEP_IDs . . . . . . . . . . . . . . . . . . . 12
7.2.2.1. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . 11 7.2.2.1. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . 12
7.2.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . 11 7.2.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . 12
7.2.2.3. Endpoint IDs for Pseudowire Segments . . . . . . . 12 7.2.2.3. Endpoint IDs Pseudowire Segments . . . . . . . . . 12
7.3. MIP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 12 7.3. MIP Identifiers . . . . . . . . . . . . . . . . . . . . . 13
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13 9. Security Considerations . . . . . . . . . . . . . . . . . . . 14
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
10.1. Normative References . . . . . . . . . . . . . . . . . . . 13 10.1. Normative References . . . . . . . . . . . . . . . . . . . 14
10.2. Informative References . . . . . . . . . . . . . . . . . . 14 10.2. Informative References . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction 1. Introduction
This document specifies identifiers to be used in within the This document specifies identifiers to be used in within the
Transport Profile of Multiprotocol Label Switching (MPLS-TP). The Transport Profile of Multiprotocol Label Switching (MPLS-TP). The
MPLS-TP requirements [12] require that the elements and objects in an MPLS-TP requirements (RFC 5654) [12] require that the elements and
MPLS-TP environment are able to be configured and managed without a objects in an MPLS-TP environment are able to be configured and
control plane. In such an environment many conventions for defining managed without a control plane. In such an environment many
identifiers are possible. This document defines identifiers for conventions for defining identifiers are possible. This document
MPLS-TP management and OAM functions suitable to ITU conventions and defines identifiers for MPLS-TP management and OAM functions suitable
to IP/MPLS conventions. Applicability of the different identifier to ITU conventions and to IP/MPLS conventions. Applicability of the
schemas to different applications are outside the scope of this different identifier schemas to different applications are outside
document. the scope of this document.
1.1. Terminology 1.1. Terminology
AII: Attachment Interface Identifier AII: Attachment Interface Identifier
AP: Attachment Point AP: Attachment Point
ASN: Autonomous System Number ASN: Autonomous System Number
FEC: Forwarding Equivalence Class FEC: Forwarding Equivalence Class
skipping to change at page 4, line 12 skipping to change at page 4, line 12
PW: Pseudowire PW: Pseudowire
RSVP: Resource Reservation Protocol RSVP: Resource Reservation Protocol
RSVP-TE: RSVP Traffic Engineering RSVP-TE: RSVP Traffic Engineering
S-PE: Switching Provider Edge S-PE: Switching Provider Edge
T-PE: Terminating Provider Edge T-PE: Terminating Provider Edge
Requirements Language 1.2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [1]. document are to be interpreted as described in RFC 2119 [1].
Notational Conventions in Backus-Naur Form 1.3. Notational Conventions in Backus-Naur Form
All multiple-word atomic identifiers use underscores (_) between the All multiple-word atomic identifiers use underscores (_) between the
words to join the words. Many of the identifiers are composed of a words to join the words. Many of the identifiers are composed of a
concatenation of other identifiers, these are expressed using Backus- concatenation of other identifiers. These are expressed using
Naur Form. Where the same identifier is used multiple times in a Backus-Naur Form (using double-colon - "::" - notation).
concatenation, they are qualified by a prefix joining it to the
Where the same identifier type is used multiple times in a
concatenation, they are qualified by a prefix joined to the
identifier by a dash (-). For example Src-Node_ID is the Node_ID of identifier by a dash (-). For example Src-Node_ID is the Node_ID of
a node referred to as Src (short for source). a node referred to as Src (where "Src" is short for "source" in this
example).
The notation does not define an implicit ordering of the information
elements involved in a concatenated identifier.
2. Named Entities 2. Named Entities
In order to configure, operate and manage a transport network based In order to configure, operate and manage a transport network based
on the MPLS Transport Profile, a number of entities require on the MPLS Transport Profile, a number of entities require
identification. Identifiers for the follow entities are defined in identification. Identifiers for the follow entities are defined in
this document: this document:
o Operator o Operator
skipping to change at page 5, line 20 skipping to change at page 5, line 26
Note that we have borrowed the term tunnel from RSVP-TE (RFC 3209) Note that we have borrowed the term tunnel from RSVP-TE (RFC 3209)
[2] where it is used to describe an entity that provides a connection [2] where it is used to describe an entity that provides a connection
between a source and destination LSR. The tunnel in turn is between a source and destination LSR. The tunnel in turn is
instantiated by one or more LSPs, where the additional LSPs are used instantiated by one or more LSPs, where the additional LSPs are used
for protection or re-grooming of the tunnel. for protection or re-grooming of the tunnel.
3. Uniquely Identifying an Operator 3. Uniquely Identifying an Operator
Two forms of identification are defined, one that is compatible with Two forms of identification are defined, one that is compatible with
IP operational practice called a Global_ID and one compatible with IP operational practice called a Global_ID and one compatible with
ITU practice, the ICC. An Operator MAY be identified either by its ITU practice, the ICC. An Operator MAY be identified either by
Global_ID or by its ICC. Global_ID or by ICC.
3.1. The Global ID 3.1. The Global ID
RFC 5003 [3] defines a globally unique Attachment Interface RFC 5003 [3] defines a globally unique Attachment Interface
Identifier (AII). That AII is composed of three parts, a Global_ID Identifier (AII). That AII is composed of three parts, a Global_ID
which uniquely identifies a operator, a prefix, and finally and which uniquely identifies a operator, a prefix, and finally and
attachment circuit identifier. We have chosen to use that Global ID attachment circuit identifier. We have chosen to use that Global ID
for MPLS-TP. Quoting from RFC 5003, section 3.2, "The global ID can for MPLS-TP. Quoting from RFC 5003, section 3.2, "The global ID can
contain the 2-octet or 4-octet value of the operator's Autonomous contain the 2-octet or 4-octet value of the operator's Autonomous
System Number (ASN). It is expected that the global ID will be System Number (ASN). It is expected that the global ID will be
skipping to change at page 6, line 21 skipping to change at page 6, line 28
Alphabetic characters in the ICC SHOULD be represented with upper Alphabetic characters in the ICC SHOULD be represented with upper
case letters. case letters.
4. Node and Interface Identifiers 4. Node and Interface Identifiers
An LSR requires identification of the node itself and of its An LSR requires identification of the node itself and of its
interfaces. An interface is the Access Point (AP) to a server layer interfaces. An interface is the Access Point (AP) to a server layer
MPLS-TP section or MPLS-TP tunnel. MPLS-TP section or MPLS-TP tunnel.
We call the identifier associated with a node a Node Identifier We call the identifier associated with a node a Node Identifier
(Node_ID). The Node_ID is a unique 32-bit unsigned integer assigned (Node_ID). The Node_ID is a unique 32-bit value assigned by the
by the operator within the scope of the Global_ID. The value 0 (or operator within the scope of the Global_ID. The value zero is
0.0.0.0 in dotted decimal notation) is reserved MUST NOT be used. reserved and MUST NOT be used. Where IPv4 addresses are used, it is
The Node_ID is not an IPv4 address. However, it was chosen to be 32- convenient to use the Node's IPv4 loopback address as the Node_ID,
bits to allow compatibility with existing MPLS deployments. In however the Node_ID does not need to have any association with the
existing MPLS deployments LSRs are generally identified by an IPv4 IPv4 address space used in the operator's IGP or BGP. Where IPv6
loopback address. Where IPv4 addresses are in use the Node_ID MAY be addresses are used exclusively, a domain unique 32- bit value is
automatically mapped to the LSR's /32 IPv4 loopback address. Note assigned
that, when IP reachability is not needed, the 32-bit Node_ID is not
required to have any association with the IPv4 address space used in
the operator's IGP or BGP.
In situations where a Node_ID needs to be globally unique, this is In situations where a Node_ID needs to be globally unique, this is
accomplished by prefixing the identifier with the operator's accomplished by prefixing the identifier with the operator's
Global_ID. The combination of Global_ID::Node_ID we call an Global Global_ID. The combination of Global_ID::Node_ID we call an Global
Node ID or Global_Node_ID. Node ID or Global_Node_ID.
Within the context of a particular node, we call the identifier Within the context of a particular node, we call the identifier
associated with an interface an Interface Number or IF_Num. The associated with an interface an Interface Number or IF_Num. The
IF_Num is a 32-bit unsigned integer assigned by the operator and MUST IF_Num is a 32-bit unsigned integer assigned by the operator and MUST
be unique within the scope of a Node_ID. The IF_Num value 0 has be unique within the scope of a Node_ID. The IF_Num value 0 has
special meaning (see section Section 7.3 and must not be used as the special meaning and MUST NOT be used as the IF_Num in an MPLS-TP
IF_Num in an MPLS-TP IF_ID. IF_ID.
An Interface Identifier or IF_ID identifies an interface uniquely An Interface Identifier or IF_ID identifies an interface uniquely
within the context of a Global_ID. It is formed by concatenating the within the context of a Global_ID. It is formed by concatenating the
Node_ID with the IF_Num. That is an IF_ID is a 64-bit identifier Node_ID with the IF_Num. That is an IF_ID is a 64-bit identifier
formed as Node_ID::IF_Num. formed as Node_ID::IF_Num.
This convention was chosen to allow compatibility with GMPLS. GMPLS This convention was chosen to allow compatibility with GMPLS. GMPLS
signaling [4] requires interface identification. GMPLS allows three signaling [4] requires interface identification. GMPLS allows three
formats for the Interface_ID. The third format consists of an IPv4 formats for the Interface_ID. The third format consists of an IPv4
Address plus a 32-bit unsigned integer for the specific interface. Address plus a 32-bit unsigned integer for the specific interface.
skipping to change at page 7, line 20 skipping to change at page 7, line 24
prefixing the identifier with the operator's Global_ID. The prefixing the identifier with the operator's Global_ID. The
combination of Global_ID::Node_ID::IF_Num we call an Global Interface combination of Global_ID::Node_ID::IF_Num we call an Global Interface
ID or Global_IF_ID. ID or Global_IF_ID.
The attachment point to an MPLS-TP Tunnel (see section Section 5.1 The attachment point to an MPLS-TP Tunnel (see section Section 5.1
also needs an interface identifier. A procedure for automatically also needs an interface identifier. A procedure for automatically
generating these is contained in that section. generating these is contained in that section.
5. MPLS-TP Tunnel and LSP Identifiers 5. MPLS-TP Tunnel and LSP Identifiers
A important construct within MPLS_TP is a connection which is An important construct within MPLS_TP is a service that may be
provided across a working and a protection LSP. Within this document identified by the server to a client, ideally using a single
we will use the term MPLS-TP Tunnel or simply tunnel for the identifier. Such a service may be provided across a working and a
connection provided by the working and protect LSPs. This section protection LSP, both of which should be similarly identified. Within
defines an MPLS-TP Tunnel_ID to uniquely identify a tunnel and this document we will use the term "MPLS-TP Tunnel" or simply
MPLS-TP LSP_IDs within the context of a tunnel. "tunnel" for a service provided by (for example) a working and
protection LSPs. This section defines an MPLS-TP Tunnel_ID to
uniquely identify a tunnel and MPLS-TP LSP_IDs within the context of
that tunnel.
For the case where multiple LSPs (for example) are used to support a
single service with a common set of end-points, using this identifier
allows for a trivial mapping between the server and client layers to
a common service identifier which may be either defined by, or used
by, the client.
Note that this usage is not intended to constrain protection schemes,
and may be used to identify any service (protected or un-protected)
that may appear to the client as a single service attachment point.
Keeping the tunnel number consistent across working and protection
LSPs is a useful construct currently employed within GMPLS. However
there is no requirement that a protection LSP use the same tunnel
number as the working LSP.
5.1. MPLS-TP Point to Point Tunnel Identifiers 5.1. MPLS-TP Point to Point Tunnel Identifiers
At each endpoint a tunnel is uniquely identified by the endpoint's At each endpoint a tunnel is uniquely identified by the endpoint's
Node_ID and a locally assigned tunnel number. Specifically a Node_ID and a locally assigned tunnel number. Specifically a
Tunnel_Num is a 16-bit unsigned integer unique within the context of Tunnel_Num is a 16-bit unsigned integer unique within the context of
the node. The motivation for each endpoint having its own tunnel the node. The motivation for each endpoint having its own tunnel
number is to allow a compact form for the MEP-ID. See section number is to allow a compact form for the MEP-ID. See section
Section 7.1.2.1. Section 7.1.2.1.
Having two tunnel-ids also serves to simplify other signaling. For Having two tunnel-ids also serves to simplify other signaling. For
instance an associated bi-directional tunnel could be setup using two instance an associated bi-directional tunnel could be setup using two
unidirectional tunnels signaled via RSVP. unidirectional tunnels signaled via RSVP.
The concatenation of the two endpoint identifier servers as the full The concatenation of the two endpoint identifiers serves as the full
identifier. In a signaled situation, the node originating the identifier. In a signaled situation, the node originating the
signaling exchange is called the source and the target node is called signaling exchange is called the source and the target node is called
the destination. In a configured environment the endpoints could the destination. In a configured environment the endpoints could
equally be called East and West. Using the signaled convention and equally be called East and West. Using the signaled convention and
abbreviating the endpoint qualifiers to Src and Dst respectively, the abbreviating the endpoint qualifiers to Src and Dst respectively, the
format of the format of a Tunnel_ID is: format of the format of a Tunnel_ID is:
Src-Node_ID::Src-Tunnel_Num::Dst-Node_ID::Dst-Tunnel_Num Src-Node_ID::Src-Tunnel_Num::Dst-Node_ID::Dst-Tunnel_Num
Where the Tunnel_ID needs to be globally unique, this is accomplished Where the Tunnel_ID needs to be globally unique, this is accomplished
skipping to change at page 8, line 32 skipping to change at page 9, line 8
Src-Node_ID::Src-Tunnel_Num::Dst-Node_ID::Dst-Tunnel_Num::LSP_Num Src-Node_ID::Src-Tunnel_Num::Dst-Node_ID::Dst-Tunnel_Num::LSP_Num
Where the LSP_ID needs to be globally unique, this is accomplished by Where the LSP_ID needs to be globally unique, this is accomplished by
using globally unique Node_IDs as defined above. Thus a globally using globally unique Node_IDs as defined above. Thus a globally
unique Tunnel_ID becomes: unique Tunnel_ID becomes:
Src-Global_Node_ID::Src-Tunnel_Num::Dst-Global_Node_ID:: Src-Global_Node_ID::Src-Tunnel_Num::Dst-Global_Node_ID::
Dst-Tunnel_Num::LSP_Num Dst-Tunnel_Num::LSP_Num
The corresponding ICC-based version of this identifier would be:
Src-ICC::Src-Tunnel_Num::Dst-ICC::Dst-Tunnel_Num::LSP_Num
5.3. Mapping to GMPLS Signalling 5.3. Mapping to GMPLS Signalling
This section defines the mapping from an MPLS-TP LSP_ID to GMPLS. At This section defines the mapping from an MPLS-TP LSP_ID to GMPLS. At
this time, GMPLS has yet to be extended to accommodate Global_IDs. this time, GMPLS has yet to be extended to accommodate Global_IDs.
Thus a mapping is only made for the network unique form of the Thus a mapping is only made for the network unique form of the
LSP_ID. LSP_ID.
GMPLS signaling [5] uses a 5-tuple to uniquely identify an LSP within GMPLS signaling [5] uses a 5-tuple to uniquely identify an LSP within
a operator's network. This tuple is composed of a Tunnel Endpoint a operator's network. This tuple is composed of a Tunnel Endpoint
Address, Tunnel_ID, Extended Tunnel ID, and Tunnel Sender Address and Address, Tunnel_ID, Extended Tunnel ID, and Tunnel Sender Address and
skipping to change at page 9, line 37 skipping to change at page 10, line 16
Identifier (AGI). That field is exactly as specified in RFC 4447. Identifier (AGI). That field is exactly as specified in RFC 4447.
FEC 129 has a notion of Source AII (SAII) and Target AII (TAII). FEC 129 has a notion of Source AII (SAII) and Target AII (TAII).
These terms are used relative to the direction of the signaling. In These terms are used relative to the direction of the signaling. In
a purely configured environment when referring to the entire PW, this a purely configured environment when referring to the entire PW, this
distinction is not critical. That is a FEC 129 of AGIa::AIIb::AIIc distinction is not critical. That is a FEC 129 of AGIa::AIIb::AIIc
is equivalent to AGIa::AIIc::AIIb. We note that in a signaled is equivalent to AGIa::AIIc::AIIb. We note that in a signaled
environment, the required convention in RFC 4447 is that at a environment, the required convention in RFC 4447 is that at a
particular endpoint, the AII associated with that endpoint comes particular endpoint, the AII associated with that endpoint comes
first. The complete PW_Path_Id is: first. The complete PW_Path_Id is:
AGI:Src-Global_ID::Src-Node_ID::Src-AC_ID::Dst-Global_ID:: AGI::Src-Global_ID::Src-Node_ID::Src-AC_ID::Dst-Global_ID::
Dst-Node_ID::Dst-AC_ID. Dst-Node_ID::Dst-AC_ID.
The corresponding ICC-based version for this identifier would be:
AGI::Src-ICC::Src-Node_ID::Src-AC_ID::Dst-ICC::Dst-Node_ID::
Dst-AC_ID
7. Maintenance Identifiers 7. Maintenance Identifiers
In MPLS-TP a Maintenance Entity Group (MEG) represents an Entity that In MPLS-TP a Maintenance Entity Group (MEG) represents an Entity that
requires management and defines a relationship between a set of requires management and defines a relationship between a set of
maintenance points. A maintenance point is either Maintenance Entity maintenance points. A maintenance point is either Maintenance Entity
Group End-point (MEP) or a Maintenance Entity Group Intermediate Group End-point (MEP) or a Maintenance Entity Group Intermediate
Point (MIP). Maintenance points are uniquely associated with a MEG. Point (MIP). Maintenance points are uniquely associated with a MEG.
Within the context of a MEG, MEPs and MIPs must be uniquely Within the context of a MEG, MEPs and MIPs must be uniquely
identified. This section defines a means of uniquely identifying identified. This section defines a means of uniquely identifying
Maintenance Entity Groups, Maintenance Entities and uniquely defining Maintenance Entity Groups, Maintenance Entities and uniquely defining
skipping to change at page 10, line 18 skipping to change at page 10, line 48
either explicitly using the MEG_IDs described above or implicitly by either explicitly using the MEG_IDs described above or implicitly by
the label of the received OAM message. the label of the received OAM message.
7.1. Maintenance Entity Group Identifiers 7.1. Maintenance Entity Group Identifiers
Maintenance Entity Group Identifiers (MEG_IDs) are required for Maintenance Entity Group Identifiers (MEG_IDs) are required for
MPLS-TP LSPs and Pseudowires. Two classes of MEG_IDs are defined, MPLS-TP LSPs and Pseudowires. Two classes of MEG_IDs are defined,
one that follows the IP compatible identifier defined above as well one that follows the IP compatible identifier defined above as well
as the ICC-format. as the ICC-format.
7.1.1. ICC based MEG_IDs 7.1.1. ICC-based MEG Identifiers
MEG_ID for MPLS-TP LSPs and Pseudowires MAY use the globally unique MEG_ID for MPLS-TP LSPs and Pseudowires MAY use the globally unique
ICC-based format. ICC-based format.
In this case, the MEG_ID is a string of up to thirteen characters, In this case, the MEG_ID is a string of up to thirteen characters,
each character being either alphabetic (i.e. A-Z) or numeric (i.e. each character being either alphabetic (i.e. A-Z) or numeric (i.e.
0-9) characters. It consists of two subfields: the ICC (as defined 0-9) characters. It consists of two subfields: the ICC (as defined
in section 3) followed by a unique MEG code (UMC). The UMC MUST be in section 3) followed by a unique MEG code (UMC). The UMC MUST be
unique within the organization identified by the ICC. unique within the organization identified by the ICC.
skipping to change at page 11, line 10 skipping to change at page 11, line 40
For Pseudowires a MEG pertains to a single PW. The IP compatible For Pseudowires a MEG pertains to a single PW. The IP compatible
MEG_ID for a PW is simply the corresponding PW_Path_ID. We note that MEG_ID for a PW is simply the corresponding PW_Path_ID. We note that
while the two identifiers are syntactically identical, they have while the two identifiers are syntactically identical, they have
different semantics. This semantic difference needs to be made different semantics. This semantic difference needs to be made
clear. For instance if both a PW_Path_ID and a PW_MEG_ID is to be clear. For instance if both a PW_Path_ID and a PW_MEG_ID is to be
encoded in TLVs different types need to be assigned for these two encoded in TLVs different types need to be assigned for these two
identifiers. identifiers.
7.2. MEP_IDs 7.2. MEP_IDs
7.2.1. ICC based MEP_IDs 7.2.1. ICC-based MEP Identifiers
ICC-based MEP_IDs for MPLS-TP LSPs and Pseudowires are formed by ICC-based MEP_IDs for MPLS-TP LSPs and Pseudowires are formed by
appending a unique number to the MEG_ID defined in section appending a unique number to the MEG_ID defined in section
Section 7.1.1 above. Within the context of a particular MEG, we call Section 7.1.1 above. Within the context of a particular MEG, we call
the identifier associated with a MEP the MEP Index (MEP_Index). The the identifier associated with a MEP the MEP Index (MEP_Index). The
MEP_Index is administratively assigned. It is encoded as a 16-bit MEP_Index is administratively assigned. It is encoded as a 16-bit
unsigned integer and MUST be unique within the MEG. An ICC-based unsigned integer and MUST be unique within the MEG. An ICC-based
MEP_ID is: MEP_ID is:
MEG_ID::MEP_Index MEG_ID::MEP_Index
skipping to change at page 12, line 4 skipping to change at page 12, line 33
In situations where global uniqueness is required this becomes: In situations where global uniqueness is required this becomes:
Src-Global_ID::Src-Node_ID::Src-Tunnel_Num::LSP_Num Src-Global_ID::Src-Node_ID::Src-Tunnel_Num::LSP_Num
7.2.2.2. MEP_IDs for Pseudowires 7.2.2.2. MEP_IDs for Pseudowires
Like MPLS-TP LSPs, Pseudowire endpoints (T-PEs) require MEP_IDs. In Like MPLS-TP LSPs, Pseudowire endpoints (T-PEs) require MEP_IDs. In
order to automatically generate MEP_IDs for PWs, we simply use the order to automatically generate MEP_IDs for PWs, we simply use the
AGI plus the AII associated with that end of the PW. Thus a MEP_ID AGI plus the AII associated with that end of the PW. Thus a MEP_ID
used in end-to-end for an Pseudowire T-PE takes the form used in end-to-end for an Pseudowire T-PE takes the form
AGI:Src-Global_ID::Src-Node_ID::Src-AC_ID, AGI:Src-Global_ID::Src-Node_ID::Src-AC_ID,
where the Node_ID is the node in which the MEP is located and where the Node_ID is the node in which the MEP is located and
Tunnel_Num is the tunnel number unique to that node. Tunnel_Num is the tunnel number unique to that node.
7.2.2.3. Endpoint IDs for Pseudowire Segments 7.2.2.3. Endpoint IDs Pseudowire Segments
In some OAM communications, messages are originated by the node at In some OAM communications, messages are originated by the node at
one end of a PW segment and relayed to the other end by setting the one end of a PW segment and relayed to the other end of that same
TTL of the PW label to one. segment by setting the TTL of the PW label to one (1). For a multi-
segment pseudowire, TTL could be set to any value that would cause
OAM messages to reach the target segment end-point (up to and
including 255).
The MEP_ID Is Formed by a combination of a PW MEP_ID and the The MEP_ID Is Formed by a combination of a PW MEP_ID and the
identification of the local node. At an S-PE, there are two PW identification of the local node. At an S-PE, there are two PW
segments. We distinguish the segments by using the MEP_ID which is segments. We distinguish the segments by using the MEP_ID which is
upstream of the PW segment in question. To complete the upstream of the PW segment in question. To complete the
identification we suffix this with the identification of the local identification we suffix this with the identification of the local
node. node.
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
| | | | | | | | | | | | | | | |
| A|---------|B C|---------|D E|---------|F | | A|---------|B C|---------|D E|---------|F |
| | | | | | | | | | | | | | | |
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
T-PE1 S-PE2 S-PE3 T-PE4 (T)PE1 (S)PE2 (S)PE3 (T)PE4
Pseudowire Maintenance Points Pseudowire Maintenance Points
For example, suppose that in the above figure all of the nodes have For example, suppose that in the above figure all of the nodes have
Global_ID GID1; the node are represented as named in the figure; and Global_ID GID1; the node are represented as named in the figure; and
The identification for the Pseudowire is: The identification for the Pseudowire is:
AGI = AGI1 AGI = AGI1
Src-Global_ID = GID1 Src-Global_ID = GID1
Src-Node_ID = T-PE1 Src-Node_ID = PE1
Src-AC_ID = AII1 Src-AC_ID = AII1
Dst-Global_ID = GID1 Dst-Global_ID = GID1
Dst-Node_ID = T-PE1 Dst-Node_ID = PE4
Dst-AC_ID = AII4 Dst-AC_ID = AII4
The PW segment endpoint at point A would be AGI1::GID1:T-PE1::AII1. The PW segment endpoint MEP_ID at point A would be -
The MP_ID at point C would be AGI1::GID1:T-PE1::AII1::GID1:S-PE2.
7.3. MIP_IDs AGI1::GID1::PE1::AII1
At a cross connect point, in order to automatically generate MIP_IDs The MP_ID at point C would be -
AGI1::GID1::PE1::AII1::GID1::PE2
7.3. MIP Identifiers
At a cross-connect point, in order to automatically generate MIP_IDs
for MPLS-TP, we simply use the IF_IDs of the two interfaces which are for MPLS-TP, we simply use the IF_IDs of the two interfaces which are
cross connected via the label bindings of the MPLS-TP LSP. If only cross-connected via the label bindings of the MPLS-TP LSP. If only
one MIP is configured, then the MIP_ID is formed using the Node_ID one MIP is configured, then the MIP_ID is formed using the Node_ID
and an IF_Num of 0. In some contexts, such as LSP Ping[13], the and an IF_Num of 0. In some contexts, such as LSP Ping[13], the
Node_ID alone may be used as the MIP_ID. Node_ID alone may be used as the MIP_ID.
8. IANA Considerations 8. IANA Considerations
There are no IANA actions resulting from this document.
9. Security Considerations 9. Security Considerations
This document describes an information model and, as such, does not
introduce security concerns. Protocol specifications that describe
use of this information model - however - may introduce security
risks and concerns about authentication of participants. For this
reason, the writers of protocol specifications for the purpose of
describing implementation of this information model need to describe
security and authentication concerns that may be raised by the
particular mechanisms defined and how those concerns may be
addressed.
10. References 10. References
10.1. Normative References 10.1. Normative References
[1] Bradner, S., "Key words for use in RFCs to Indicate Requirement [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[2] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and [2] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and
G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels",
RFC 3209, December 2001. RFC 3209, December 2001.
skipping to change at page 14, line 5 skipping to change at page 15, line 6
Unnumbered Links in CR-LDP (Constraint-Routing Label Unnumbered Links in CR-LDP (Constraint-Routing Label
Distribution Protocol)", RFC 3480, February 2003. Distribution Protocol)", RFC 3480, February 2003.
[8] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in [8] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in
MPLS Traffic Engineering (TE)", RFC 4201, October 2005. MPLS Traffic Engineering (TE)", RFC 4201, October 2005.
[9] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE [9] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
Extensions in Support of End-to-End Generalized Multi-Protocol Extensions in Support of End-to-End Generalized Multi-Protocol
Label Switching (GMPLS) Recovery", RFC 4872, May 2007. Label Switching (GMPLS) Recovery", RFC 4872, May 2007.
[10] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "BFD [10] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
For MPLS LSPs", draft-ietf-bfd-mpls-07 (work in progress), "Bidirectional Forwarding Detection (BFD) for MPLS Label
June 2008. Switched Paths (LSPs)", RFC 5884, June 2010.
[11] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding [11] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding
Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Detection (BFD) for the Pseudowire Virtual Circuit Connectivity
Verification (VCCV)", draft-ietf-pwe3-vccv-bfd-07 (work in Verification (VCCV)", RFC 5885, June 2010.
progress), July 2009.
10.2. Informative References 10.2. Informative References
[12] Vigoureux, M. and D. Ward, "Requirements for OAM in MPLS [12] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and
Transport Networks", draft-ietf-mpls-tp-oam-requirements-06 S. Ueno, "Requirements of an MPLS Transport Profile", RFC 5654,
(work in progress), March 2010. September 2009.
[13] Kompella, K. and G. Swallow, "Detecting Multi-Protocol Label [13] Kompella, K. and G. Swallow, "Detecting Multi-Protocol Label
Switched (MPLS) Data Plane Failures", RFC 4379, February 2006. Switched (MPLS) Data Plane Failures", RFC 4379, February 2006.
[14] Ohta, H., "Assignment of the 'OAM Alert Label' for [14] Ohta, H., "Assignment of the 'OAM Alert Label' for
Multiprotocol Label Switching Architecture (MPLS) Operation and Multiprotocol Label Switching Architecture (MPLS) Operation and
Maintenance (OAM) Functions", RFC 3429, November 2002. Maintenance (OAM) Functions", RFC 3429, November 2002.
[15] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and [15] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
S. Ueno, "MPLS-TP Requirements", Operations, Administration, and Maintenance (OAM) in MPLS
draft-ietf-mpls-tp-requirements-10 (work in progress), Transport Networks", RFC 5860, May 2010.
August 2009.
[16] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Berger, "A [16] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Berger, "A
Framework for MPLS in Transport Networks", Framework for MPLS in Transport Networks", RFC 5921, July 2010.
draft-ietf-mpls-tp-framework-12 (work in progress), May 2010.
Authors' Addresses Authors' Addresses
Matthew Bocci Matthew Bocci
Alcatel-Lucent Alcatel-Lucent
Voyager Place, Shoppenhangers Road Voyager Place, Shoppenhangers Road
Maidenhead, Berks SL6 2PJ Maidenhead, Berks SL6 2PJ
UK UK
Email: matthew.bocci@alcatel-lucent.com Email: matthew.bocci@alcatel-lucent.com
George Swallow George Swallow
Cisco Cisco
Email: swallow@cisco.com Email: swallow@cisco.com
Eric Gray
Ericsson
900 Chelmsford Street
Lowell, Massachussetts 01851-8100
Email: eric.gray@ericsson.com
 End of changes. 44 change blocks. 
87 lines changed or deleted 138 lines changed or added

This html diff was produced by rfcdiff 1.40. The latest version is available from http://tools.ietf.org/tools/rfcdiff/