draft-ietf-mpls-tp-identifiers-05.txt   draft-ietf-mpls-tp-identifiers-06.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: December 16, 2011 Cisco Expires: December 26, 2011 Cisco
E. Gray E. Gray
Ericsson Ericsson
June 14, 2011 June 24, 2011
MPLS-TP Identifiers MPLS-TP Identifiers
draft-ietf-mpls-tp-identifiers-05 draft-ietf-mpls-tp-identifiers-06
Abstract Abstract
This document specifies identifiers for MPLS-TP objects. Included This document specifies an initial set of identifiers to be used in
are identifiers conformant to existing ITU conventions and the Transport Profile of Multiprotocol Label Switching (MPLS-TP).
identifiers which are compatible with existing IP, MPLS, GMPLS, and The MPLS-TP requirements (RFC 5654) require that the elements and
Pseudowire definitions. objects in an MPLS-TP environment are able to be configured and
managed without a control plane. In such an environment many
conventions for defining identifiers are possible. This document
defines identifiers for MPLS-TP management and OAM functions suitable
to IP/MPLS conventions.
This document is a product of a joint Internet Engineering Task Force This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication (IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge
(PWE3) architectures to support the capabilities and functionalities (PWE3) architectures to support the capabilities and functionalities
of a packet transport network as defined by the ITU-T. of a packet transport network as defined by the ITU-T.
Status of this Memo Status of this Memo
skipping to change at page 1, line 43 skipping to change at page 1, line 47
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 December 16, 2011. This Internet-Draft will expire on December 26, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 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
skipping to change at page 2, line 17 skipping to change at page 2, line 19
(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 . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Requirements Language . . . . . . . . . . . . . . . . . . 5 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.3. Notational Conventions . . . . . . . . . . . . . . . . . . 5 1.3. Notational Conventions . . . . . . . . . . . . . . . . . . 4
2. Named Entities . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Named Entities . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Uniquely Identifying an Operator . . . . . . . . . . . . . . . 6 3. Uniquely Identifying an Operator - the Global_ID . . . . . . . 5
3.1. The Global ID . . . . . . . . . . . . . . . . . . . . . . 7 4. Node and Interface Identifiers . . . . . . . . . . . . . . . . 6
3.2. ITU Carrier Code . . . . . . . . . . . . . . . . . . . . . 7 5. MPLS-TP Tunnel and LSP Identifiers . . . . . . . . . . . . . . 7
4. Node and Interface Identifiers . . . . . . . . . . . . . . . . 8 5.1. MPLS-TP Point to Point Tunnel Identifiers . . . . . . . . 8
5. MPLS-TP Tunnel and LSP Identifiers . . . . . . . . . . . . . . 9 5.2. MPLS-TP LSP Identifiers . . . . . . . . . . . . . . . . . 8
5.1. MPLS-TP Point to Point Tunnel Identifiers . . . . . . . . 9 5.2.1. MPLS-TP Co-Routed Bidirectional LSP Identifiers . . . 8
5.2. MPLS-TP LSP Identifiers . . . . . . . . . . . . . . . . . 10 5.2.2. MPLS-TP Associated Bidirectional LSP Identifiers . . . 9
5.2.1. MPLS-TP Co-Routed Bidirectional LSP Identifiers . . . 10 5.3. Mapping to RSVP Signaling . . . . . . . . . . . . . . . . 9
5.2.2. MPLS-TP Associated Bidirectional LSP Identifiers . . . 11 6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 11
5.3. Mapping to RSVP Signaling . . . . . . . . . . . . . . . . 12 7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 12
6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 13 7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 12
7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 14 7.1.1. MPLS-TP Section MEG_IDs . . . . . . . . . . . . . . . 12
7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 14 7.1.2. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . . . 12
7.1.1. ICC-based MEG Identifiers . . . . . . . . . . . . . . 14 7.1.3. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . . . 13
7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 14 7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1.2.1. MPLS-TP Section MEG_IDs . . . . . . . . . . . . . 14 7.2.1. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . . . 13
7.1.2.2. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 15 7.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . . . 14
7.1.2.3. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 15 7.3. Pseudowire Segment Endpoint IDs . . . . . . . . . . . . . 14
7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 15 7.4. MIP Identifiers . . . . . . . . . . . . . . . . . . . . . 15
7.2.1. ICC-based MEP Identifiers . . . . . . . . . . . . . . 15 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7.2.2. IP based MEP_IDs . . . . . . . . . . . . . . . . . . . 15 9. Security Considerations . . . . . . . . . . . . . . . . . . . 15
7.2.2.1. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7.2.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . 16 10.1. Normative References . . . . . . . . . . . . . . . . . . . 16
7.2.2.3. Pseudowire Segments Endpoint IDs . . . . . . . . . 16 10.2. Informative References . . . . . . . . . . . . . . . . . . 16
7.3. MIP Identifiers . . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 17
9. Security Considerations . . . . . . . . . . . . . . . . . . . 18
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10.1. Normative References . . . . . . . . . . . . . . . . . . . 18
10.2. Informative References . . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
1. Introduction 1. Introduction
This document specifies identifiers to be used in the Transport This document specifies an initial set of identifiers to be used in
Profile of Multiprotocol Label Switching (MPLS-TP). The MPLS-TP the Transport Profile of Multiprotocol Label Switching (MPLS-TP).
requirements (RFC 5654) [7] require that the elements and objects in The MPLS-TP requirements (RFC 5654) [7] require that the elements and
an MPLS-TP environment are able to be configured and managed without objects in an MPLS-TP environment are able to be configured and
a control plane. In such an environment many conventions for managed without a control plane. In such an environment many
defining identifiers are possible. This document defines identifiers conventions for defining identifiers are possible. This document
for MPLS-TP management and OAM functions suitable to ITU conventions defines identifiers for MPLS-TP management and OAM functions suitable
and to IP/MPLS conventions. Applicability of the different to IP/MPLS conventions. The identifiers have been chosen to be
identifier schemas to different applications is outside the scope of compatible with existing IP, MPLS, GMPLS, and Pseudowire definitions.
this document.
This document is a product of a joint Internet Engineering Task Force This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication (IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge Profile within the IETF MPLS and Pseudowire Emulation Edge-to-Edge
(PWE3) architectures to support the capabilities and functionalities (PWE3) architectures to support the capabilities and functionalities
of a packet transport network as defined by the ITU-T. of a packet transport network as defined by the ITU-T.
1.1. Terminology 1.1. Terminology
AII: Attachment Interface Identifier AII: Attachment Interface Identifier
ASN: Autonomous System Number ASN: Autonomous System Number
EGP: Exterior Gateway Protocol EGP: Exterior Gateway Protocol
FEC: Forwarding Equivalence Class FEC: Forwarding Equivalence Class
GMPLS: Generalized Multi-Protocol Label Switching GMPLS: Generalized Multi-Protocol Label Switching
ICC: ITU Carrier Code
IGP: Interior Gateway Protocol IGP: Interior Gateway Protocol
LSP: Label Switched Path LSP: Label Switched Path
LSR: Label Switching Router LSR: Label Switching Router
ME: Maintenance Entity
MEG: Maintenance Entity Group MEG: Maintenance Entity Group
MEP: Maintenance Entity Group End Point MEP: Maintenance Entity Group End Point
MIP: Maintenance Entity Group Intermediate Point MIP: Maintenance Entity Group Intermediate Point
MPLS: Multi-Protocol Label Switching MPLS: Multi-Protocol Label Switching
NNI: Network-to-Network Interface NNI: Network-to-Network Interface
OAM: Operations, Administration and Maintenance OAM: Operations, Administration and Maintenance
P2MP: Point to Multi-Point
P2P: Point to Point P2P: Point to Point
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
skipping to change at page 6, line 5 skipping to change at page 4, line 45
Specifically the designation A1 is used to indicate the lower sort Specifically the designation A1 is used to indicate the lower sort
order of a field or set of fields and Z9 is used to indicated the order of a field or set of fields and Z9 is used to indicated the
higher sort order of the same. The sort is either alphanumeric or higher sort order of the same. The sort is either alphanumeric or
numeric depending on the field's definition. Where the sort applies numeric depending on the field's definition. Where the sort applies
to a group of fields, those fields are grouped with {...}. to a group of fields, those fields are grouped with {...}.
Note, however, that the uniqueness of an identifier does not depend Note, however, that the uniqueness of an identifier does not depend
on the ordering, but rather, upon the uniqueness and scoping of the on the ordering, but rather, upon the uniqueness and scoping of the
fields that compose the identifier. Further the preferred ordering fields that compose the identifier. Further the preferred ordering
is not intended to constrain protocol designs by dictating a is not intended to constrain protocol designs by dictating a
particular field sequence or even what fields appear in which particular field sequence (for example see Section 5.2.1) or even
objects. For example see Section 5.3. what fields appear in which objects (for example see Section 5.3).
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 following entities are defined identification. Identifiers for the following entities are defined
in this document: in this document:
* Operator * Global_ID
+ Global_ID * Node
+ ICC * Interface
* LSR * Tunnel
* LSP * LSP
* PW * PW
* Interface
* MEG * MEG
* MEP * MEP
* MIP * MIP
* Tunnel
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 logical [2] where it is used to describe an entity that provides a logical
association between a source and destination LSR. The tunnel in turn association between a source and destination LSR. The tunnel in turn
is instantiated by one or more LSPs, where the additional LSPs are is instantiated by one or more LSPs, where the additional LSPs are
used for protection or re-grooming of the tunnel. used for protection or re-grooming of the tunnel.
3. Uniquely Identifying an Operator 3. Uniquely Identifying an Operator - the Global_ID
An operator is uniquely identified by an identifier which may take
one of two formats. One format is compatible with IP operational
practice, and is called a Global_ID. The other format is compatible
with ITU practice and is called ICC. An operator MAY use either the
Global_ID or ICC format.
3.1. The Global ID
RFC 5003 [3] defines a globally unique Attachment Interface The Global_ID is defined to uniquely identify an operator. RFC 5003
Identifier (AII). That AII is composed of three parts, a Global_ID [3] defines a globally unique Attachment Interface Identifier (AII).
which uniquely identifies an operator, a prefix, and finally, an That AII is composed of three parts, a Global_ID which uniquely
attachment circuit identifier. We have chosen to use that Global ID identifies an operator, a prefix, and finally, an attachment circuit
for MPLS-TP. Quoting from RFC 5003, section 3.2, "The global ID can identifier. We have chosen to use that Global ID for MPLS-TP.
contain the 2-octet or 4-octet value of the operator's Autonomous Quoting from RFC 5003, section 3.2, "The global ID can contain the
System Number (ASN). It is expected that the global ID will be 2-octet or 4-octet value of the operator's Autonomous System Number
derived from the globally unique ASN of the autonomous system hosting (ASN). It is expected that the global ID will be derived from the
the PEs containing the actual AIIs. The presence of a global ID globally unique ASN of the autonomous system hosting the PEs
based on the operator's ASN ensures that the AII will be globally containing the actual AIIs. The presence of a global ID based on the
unique." operator's ASN ensures that the AII will be globally unique."
A Global_ID must be derived from a 4-octet AS number assigned to the A Global_ID must be derived from a 4-octet AS number assigned to the
operator. Note that 2-octet AS numbers have been incorporated in the operator. Note that 2-octet AS numbers have been incorporated in the
4-octet by placing the 2-octet AS number, in the low-order octets and 4-octet by placing the 2-octet AS number, in the low-order octets and
setting the two high-order octets to zero. setting the two high-order octets to zero.
ASN 0 is reserved and cannot be assigned. A Global_ID of zero means ASN 0 is reserved and cannot be assigned. A Global_ID of zero means
that no Global_ID is specified. Note that a Global_ID of zero is that no Global_ID is specified. Note that a Global_ID of zero is
limited to entities contained within a single operator and MUST NOT limited to entities contained within a single operator and MUST NOT
be used across an NNI. be used across an NNI.
The Global_ID is used solely to provide a globally unique context for The Global_ID is used solely to provide a globally unique context for
other MPLS-TP identifiers. While the AS Number used in the Global_ID other MPLS-TP identifiers. While the AS Number used in the Global_ID
MUST be one which the operator is entitles to use, the use of the MUST be one which the operator is entitled to use, the use of the
Global_ID is not related to the use of the ASN in protocols such as Global_ID is not related to the use of the ASN in protocols such as
BGP. BGP.
3.2. ITU Carrier Code
M.1400 defines the ITU Carrier Code (ICC) assigned to a network
operator/service provider and maintained by the ITU-T
Telecommunication Standardization Bureau (TSB): www.itu.int/ITU-T/
inr/icc/index.html.
ICCs can be assigned both to ITU-T and non-ITU-T members and the
referenced local ICC website may contain ICCs of operators of both
kinds.
The ICC is a string of one to six characters, each character being
either alphabetic (i.e. A-Z) or numeric (i.e. 0-9) characters.
Alphabetic characters in the ICC SHOULD be represented with upper
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 attachment point to a server interfaces. An interface is the attachment point to a server
(sub-)layer, e.g., MPLS-TP section or MPLS-TP tunnel. (sub-)layer, e.g., 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 value assigned by the (Node_ID). The Node_ID is a unique 32-bit value assigned by the
operator within the scope of a Global_ID or ICC. The structure of operator within the scope of a Global_ID. The structure of the
the Node_ID is operator specific and is outside the scope of this Node_ID is operator specific and is outside the scope of this
document. However, the value zero is reserved and MUST NOT be used. document. However, the value zero is reserved and MUST NOT be used.
Where IPv4 addresses are used, it may be convenient to use the Node's Where IPv4 addresses are used, it may be convenient to use the Node's
IPv4 loopback address as the Node_ID, however the Node_ID does not IPv4 loopback address as the Node_ID, however the Node_ID does not
need to have any association with the IPv4 address space used in the need to have any association with the IPv4 address space used in the
operator's IGP or EGP. Where IPv6 addresses are used exclusively, a operator's IGP or EGP. Where IPv6 addresses are used exclusively, a
32-bit value unique within the scope of a Global_ID or ICC is 32-bit value unique within the scope of a Global_ID is assigned.
assigned.
An LSR can support multiple layers (e.g. hierarchical LSPs) and the An LSR can support multiple layers (e.g. hierarchical LSPs) and the
Node_ID belongs to the multiple layer context i.e. it is applicable Node_ID belongs to the multiple layer context i.e. it is applicable
to all LSPs or PWs that originate on, have a intermediate point on, to all LSPs or PWs that originate on, have a intermediate point on,
or terminate on the node. or terminate on the node.
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 or ICC. Global_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 (IF_Num). The associated with an interface an Interface Number (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 7.3, MIP Identifiers) and MUST NOT be special meaning (see Section 7.4, MIP Identifiers) and MUST NOT be
used to identify an MPLS-TP interface. used to identify an MPLS-TP interface.
An Interface Identifier (IF_ID) identifies an interface uniquely An Interface Identifier (IF_ID) identifies an interface uniquely
within the context of a Global_ID or ICC. It is formed by within the context of a Global_ID. It is formed by concatenating the
concatenating the Node_ID with the IF_Num. That is an IF_ID is a 64- Node_ID with the IF_Num. That is, an IF_ID is a 64-bit identifier
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. The
signaling [4] requires interface identification. GMPLS allows three GMPLS signaling functional description [4] requires interface
formats for the Interface_ID. The third format consists of an IPv4 identification. GMPLS allows three formats for the Interface_ID.
Address plus a 32-bit unsigned integer for the specific interface. The third format consists of an IPv4 Address plus a 32-bit unsigned
The format defined for MPLS-TP is consistent with this format, but integer for the specific interface. The format defined for MPLS-TP
uses the Node_ID instead of an IPv4 Address. is consistent with this format, but uses the Node_ID instead of an
IPv4 Address.
If an IF_ID needs to be globally unique, this is accomplished by If an IF_ID needs to be globally unique, this is accomplished by
prefixing the identifier with the operator's Global_ID or ICC. prefixing the identifier with the operator's Global_ID.
The attachment point to an MPLS-TP Tunnel (see Section 5.1) also The attachment point to an MPLS-TP Tunnel (see Section 5.1) also
needs an interface identifier. Note that MPLS-TP supports needs an interface identifier. Note that MPLS-TP supports
hierarchical tunnels. The attachment point to a MPLS-TP Tunnel at hierarchical tunnels. The attachment point to a MPLS-TP Tunnel at
any (sub-)layer requires a node-unique IF_Num. any (sub-)layer requires a node-unique IF_Num.
5. MPLS-TP Tunnel and LSP Identifiers 5. MPLS-TP Tunnel and LSP Identifiers
In MPLS the actual transport of packets is provided by label switched In MPLS the actual transport of packets is provided by label switched
paths (LSPs). A transport service may be composed of multiple LSPs. paths (LSPs). A transport service may be composed of multiple LSPs.
Further the LSPs providing a service may change over time due to Further the LSPs providing a service may change over time due to
protection and restoration events. In order to clearly identify the protection and restoration events. In order to clearly identify the
service we use the term "MPLS-TP Tunnel" or simply "tunnel" for a service we use the term "MPLS-TP Tunnel" or simply "tunnel" for a
service provided by (for example) a working LSP and protected by a service provided by (for example) a working LSP and protected by a
protection LSP. The Tunnel_ID identifies the transport service and protection LSP. The Tunnel_ID identifies the transport service and
provides a stable binding to the client in the face of changes in the provides a stable binding to the client in the face of changes in the
the data plane LSPs used to provide the service due to protection or the data plane LSPs used to provide the service due to protection or
restoration events. This section defines an MPLS-TP Tunnel_ID to restoration events. This section defines an MPLS-TP Tunnel_ID to
uniquely identify a tunnel and MPLS-TP LSP_IDs within the context of uniquely identify a tunnel, and an MPLS-TP LSP_ID to uniquely
that tunnel. identify an LSP associated with a tunnel.
For the case where multiple LSPs (for example) are used to support a 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 single service with a common set of end-points, using the Tunnel_ID
allows for a trivial mapping between the server and client layers, allows for a trivial mapping between the server and client layers,
providing a common service identifier which may be either defined by, providing a common service identifier which may be either defined by,
or used by, the client. or used by, the client.
Note that this usage is not intended to constrain protection schemes, Note that this usage is not intended to constrain protection schemes,
and may be used to identify any service (protected or unprotected) and may be used to identify any service (protected or unprotected)
that may appear to the client as a single service attachment point. that may appear to the client as a single service attachment point.
Keeping the Tunnel_ID consistent across working and protection LSPs Keeping the Tunnel_ID consistent across working and protection LSPs
is a useful construct currently employed within GMPLS. The Tunnel_ID is a useful construct currently employed within GMPLS. However, the
for a protection LSP MAY differ from that used by its corresponding Tunnel_ID for a protection LSP MAY differ from that used by its
working LSP. corresponding 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_ID. The motivation for each endpoint having its own tunnel the Node_ID. The motivation for each endpoint having its own tunnel
number is to allow a compact form for the MEP-ID. See number is to allow a compact form for the MEP-ID. See Section 7.2.1.
Section 7.2.2.1.
Having two tunnel numbers also serves to simplify other signaling Having two tunnel numbers also serves to simplify other signaling
(e.g., setup of associated bidirectional tunnels as described in (e.g., setup of associated bidirectional tunnels as described in
Section 5.3). Section 5.3).
The concatenation of the two endpoint identifiers serves as the full The concatenation of the two endpoint identifiers serves as the full
identifier. Using the A1 / Z9 convention the format of a Tunnel_ID identifier. Using the A1/Z9 convention the format of a Tunnel_ID is:
is:
A1-{Node_ID::Tunnel_Num}::Z9-{Node_ID::Tunnel_Num} A1-{Node_ID::Tunnel_Num}::Z9-{Node_ID::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
by using globally unique Node_IDs as defined above. Thus a globally by using globally unique Node_IDs as defined above. Thus a globally
unique Tunnel_ID becomes: unique Tunnel_ID becomes:
A1-{Global_ID::Node_ID::Tunnel_Num}::Z9-{Global_Id::Node_ID:: A1-{Global_ID::Node_ID::Tunnel_Num}::Z9-{Global_Id::Node_ID::
Tunnel_Num} Tunnel_Num}
The corresponding ICC-based version of this identifier would be:
A1-{ICC::Node_ID::Tunnel_Num}::Z9-{ICC::Node_ID::Tunnel_Num}
When an MPLS-TP Tunnel is configured, it MUST be assigned a unique When an MPLS-TP Tunnel is configured, it MUST be assigned a unique
IF_ID at each endpoint. As usual, the IF_ID is composed of the local IF_ID at each endpoint. As usual, the IF_ID is composed of the local
Node_ID concatenated with a 32-bit IF_Num. Node_ID concatenated with a 32-bit IF_Num.
5.2. MPLS-TP LSP Identifiers 5.2. MPLS-TP LSP Identifiers
5.2.1. MPLS-TP Co-Routed Bidirectional LSP Identifiers 5.2.1. MPLS-TP Co-Routed Bidirectional LSP Identifiers
A co-routed bidirectional LSP can be uniquely identified by a single A co-routed bidirectional LSP can be uniquely identified by a single
LSP number within the scope of an MPLS-TP Tunnel_ID. Specifically an LSP number within the scope of an MPLS-TP Tunnel_ID. Specifically an
LSP_Num is a 16-bit unsigned integer unique within the Tunnel_ID. LSP_Num is a 16-bit unsigned integer unique within the Tunnel_ID.
Thus the format of an MPLS-TP co-routed bidirectional LSP_ID is: Thus the format of an MPLS-TP co-routed bidirectional LSP_ID is:
A1-{Node_ID::Tunnel_Num}::Z9-{Node_ID::Tunnel_Num}::LSP_Num A1-{Node_ID::Tunnel_Num}::Z9-{Node_ID::Tunnel_Num}::LSP_Num
Note that the uniqueness of identifiers does not depend on the A1 / Note that the uniqueness of identifiers does not depend on the A1/Z9
Z9 sort ordering. Thus the identifier, sort ordering. Thus the identifier
Z9-{Node_ID::Tunnel_Num}::A1-{Node_ID::Tunnel_Num}::LSP_Num Z9-{Node_ID::Tunnel_Num}::A1-{Node_ID::Tunnel_Num}::LSP_Num
is synonymous with the one above. is synonymous with the one above.
At the dataplane level, a co-routed bidirectional LSP is composed of At the dataplane level, a co-routed bidirectional LSP is composed of
two unidirectional LSPs traversing the same links in opposite two unidirectional LSPs traversing the same links in opposite
directions. Since a co-routed bidirectional LSP is provisioned or directions. Since a co-routed bidirectional LSP is provisioned or
signaled as a single entity, a single LSP_Num is used for both signaled as a single entity, a single LSP_Num is used for both
unidirectional LSPs. The unidirectional LSPs can be referenced by unidirectional LSPs. The unidirectional LSPs can be referenced by
the identifiers: the identifiers:
Z9-Node_ID::Z9-Tunnel_Num::LSP_Num::A1-Node_ID and A1-Node_ID::A1-Tunnel_Num::LSP_Num::Z9-Node_ID and
A1-Node_ID::A1-Tunnel_Num::LSP_Num::Z9-Node_ID respectively.
Z9-Node_ID::Z9-Tunnel_Num::LSP_Num::A1-Node_ID respectively.
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 LSP_ID becomes: unique LSP_ID becomes:
A1-{Global_ID::Node_ID::Tunnel_Num}::Z9-{Global_Id:: A1-{Global_ID::Node_ID::Tunnel_Num}::Z9-{Global_Id::
Node_ID::Tunnel_Num}::LSP_Num Node_ID::Tunnel_Num}::LSP_Num
The corresponding ICC-based version of this identifier would be:
A1-{ICC::Node_ID::Tunnel_Num}::Z9-{ICC::Node_ID::Tunnel_Num}::
LSP_Num
5.2.2. MPLS-TP Associated Bidirectional LSP Identifiers 5.2.2. MPLS-TP Associated Bidirectional LSP Identifiers
For an associated bidirectional LSP each of the unidirectional LSPs For an associated bidirectional LSP each of the unidirectional LSPs
from A1 to Z9 and Z9 to A1 require LSP_Nums. Each LSP is uniquely from A1 to Z9 and Z9 to A1 require LSP_Nums. Each unidirectional LSP
identified by a single LSP number within the scope of the ingress's is uniquely identified by a single LSP number within the scope of the
Tunnel_Num. Specifically an LSP_Num is a 16-bit unsigned integer ingress's Tunnel_Num. Specifically an LSP_Num is a 16-bit unsigned
unique within the Tunnel_Num. Thus the format of an MPLS-TP integer unique within the scope of the ingress's Tunnel_Num. Thus the
associated bidirectional LSP_ID is: format of an MPLS-TP associated bidirectional LSP_ID is:
A1-{Node_ID::Tunnel_Num::LSP_Num}:: A1-{Node_ID::Tunnel_Num::LSP_Num}::
Z9-{Node_ID::Tunnel_Num::LSP_Num} Z9-{Node_ID::Tunnel_Num::LSP_Num}
At the dataplane level, an associated bidirectional LSP is composed At the dataplane level, an associated bidirectional LSP is composed
of two unidirectional LSPs between two nodes in opposite directions. of two unidirectional LSPs between two nodes in opposite directions.
The unidirectional LSPs may be referenced by the identifiers: The unidirectional LSPs may be referenced by the identifiers:
A1-Node_ID::A1-Tunnel_Num::A1-LSP_Num::Z9-Node_ID and A1-Node_ID::A1-Tunnel_Num::A1-LSP_Num::Z9-Node_ID and
Z9-Node_ID::Z9-Tunnel_Num::Z9-LSP_Num::A1-Node_ID respectively. Z9-Node_ID::Z9-Tunnel_Num::Z9-LSP_Num::A1-Node_ID respectively.
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 LSP_ID becomes: unique LSP_ID becomes:
A1-{Global_ID::Node_ID::Tunnel_Num::LSP_Num}:: A1-{Global_ID::Node_ID::Tunnel_Num::LSP_Num}::
Z9-{Global_Id::Node_ID::Tunnel_Num::LSP_Num} Z9-{Global_Id::Node_ID::Tunnel_Num::LSP_Num}
The corresponding ICC-based version of this identifier would be:
A1-{ICC::Node_ID::Tunnel_Num::LSP_Num}::
Z9-{ICC::Node_ID::Tunnel_Num::LSP_Num}
5.3. Mapping to RSVP Signaling 5.3. Mapping to RSVP Signaling
This section is informative and exists to help understand the This section is informative and exists to help understand the
structure of the LSP IDs. structure of the LSP IDs.
Both GMPLS and RSVP-TE use RSVP signaling. This section defines the GMPLS [5] is based on RSVP-TE [2]. This section defines the mapping
mapping from an MPLS-TP LSP_ID to RSVP. At this time, RSVP has yet from an MPLS-TP LSP_ID to RSVP-TE. At this time, RSVP-TE has yet to
to be extended to accommodate Global_IDs. Thus a mapping is only be extended to accommodate Global_IDs. Thus a mapping is only made
made for the network unique form of the LSP_ID. for the network unique form of the LSP_ID.
RSVP signaling [5] uses a 5-tuple to uniquely identify an LSP within GMPLS and RSVP-TE signaling use a 5-tuple to uniquely identify an LSP
a operator's network. This tuple is composed of a Tunnel Endpoint within a operator's network. This tuple is composed of a Tunnel
Address, Tunnel_ID, Extended Tunnel ID, and Tunnel Sender Address and Endpoint Address, Tunnel_ID, Extended Tunnel ID, and Tunnel Sender
(RSVP) LSP_ID. Address and (RSVP) LSP_ID.
For a co-routed bidirectional LSP signaled from A1 to Z9, the mapping For a co-routed bidirectional LSP signaled from A1 to Z9, the mapping
to the GMPLS 5-tuple is as follows: to the GMPLS 5-tuple is as follows:
* Tunnel Endpoint Address = Z9-Node_ID * Tunnel Endpoint Address = Z9-Node_ID
* Tunnel_ID = A1-Tunnel_Num * Tunnel_ID = A1-Tunnel_Num
* Extended Tunnel_ID = A1-Node_ID * Extended Tunnel_ID = A1-Node_ID
* Tunnel Sender Address = A1-Node_ID * Tunnel Sender Address = A1-Node_ID
* (RSVP) LSP_ID = LSP_Num * (RSVP) LSP_ID = LSP_Num
An associated bidirectional LSP between two nodes A1 and Z9 consists An associated bidirectional LSP between two nodes A1 and Z9 consists
of two unidirectional LSPs, one from A1 to Z9 and one from Z9 to A1. of two unidirectional LSPs, one from A1 to Z9 and one from Z9 to A1.
In situations where a mapping to the RSVP 5-tuples is required, the In situations where a mapping to the RSVP-TE 5-tuples is required,
following mappings are used. For the A1 to Z9 LSP the mapping would the following mappings are used. For the A1 to Z9 LSP the mapping
be: would be:
* Tunnel Endpoint Address = Z9-Node_ID * Tunnel Endpoint Address = Z9-Node_ID
* Tunnel_ID = A1-Tunnel_Num * Tunnel_ID = A1-Tunnel_Num
* Extended Tunnel_ID = A1-Node_ID * Extended Tunnel_ID = A1-Node_ID
* Tunnel Sender Address = A1-Node_ID * Tunnel Sender Address = A1-Node_ID
* (RSVP) LSP_ID = A1-LSP_Num * (RSVP) LSP_ID = A1-LSP_Num
skipping to change at page 13, line 24 skipping to change at page 11, line 19
6. Pseudowire Path Identifiers 6. Pseudowire Path Identifiers
Pseudowire signaling (RFC 4447 [6]) defines two FECs used to signal Pseudowire signaling (RFC 4447 [6]) defines two FECs used to signal
pseudowires. Of these, FEC Type 129 along with AII Type 2 as defined pseudowires. Of these, FEC Type 129 along with AII Type 2 as defined
in RFC 5003 [3] fits the identification requirements of MPLS-TP. in RFC 5003 [3] fits the identification requirements of MPLS-TP.
In an MPLS-TP environment, a PW is identified by a set of identifiers In an MPLS-TP environment, a PW is identified by a set of identifiers
which can be mapped directly to the elements required by FEC 129 and which can be mapped directly to the elements required by FEC 129 and
AII Type 2. To distinguish this identifier from other Pseudowire AII Type 2. To distinguish this identifier from other Pseudowire
Identifiers, we call this a Pseudowire Path Identifier (PW_Path_Id). Identifiers, we call this a Pseudowire Path Identifier (PW_Path_ID).
The AII Type 2 is composed of three fields. These are the Global_ID, The AII Type 2 is composed of three fields. These are the Global_ID,
the Prefix, and the AC_ID. The Global_ID used in this document is the Prefix, and the AC_ID. The Global_ID used in this document is
identical to the Global_ID defined in RFC 5003. The Node_ID is used identical to the Global_ID defined in RFC 5003. The Node_ID is used
as the Prefix. The AC_ID is as defined in RFC 5003. as the Prefix. The AC_ID is as defined in RFC 5003.
To complete the FEC 129, all that is required is a Attachment Group To complete the FEC 129, all that is required is an Attachment Group
Identifier (AGI). That field is exactly as specified in RFC 4447. Identifier (AGI). That field is exactly as specified in RFC 4447. A
FEC 129 has a notion of Source AII (SAII) and Target AII (TAII). (bidirectional) pseudowire consists of a pair of unidirectional LSPs,
These terms are used relative to the direction of the signaling. In one in each direction. Thus for signaling, FEC 129 has a notion of
a purely configured environment when referring to the entire PW, this Source AII (SAII) and Target AII (TAII). These terms are used
distinction is not critical. That is a FEC 129 of AGIa::AIIb::AIIc relative to the direction of the LSP.
is equivalent to AGIa::AIIc::AIIb. We note that in a signaled
environment, the required convention in RFC 4447 is that at a In a purely configured environment when referring to the entire PW,
particular endpoint, the AII associated with that endpoint comes this distinction is not critical. That is a FEC 129 of AGIa::AIIb::
first. The complete PW_Path_Id is: AIIc is equivalent to AGIa::AIIc::AIIb.
We note that in a signaled environment, the required convention in
RFC 4447 is that at a particular endpoint, the AII associated with
that endpoint comes first. The complete PW_Path_ID is:
AGI::A1-{Global_ID::Node_ID::AC_ID}:: AGI::A1-{Global_ID::Node_ID::AC_ID}::
Z9-{Global_Id::Node_ID::AC_ID}. Z9-{Global_ID::Node_ID::AC_ID}.
The corresponding ICC-based version for this identifier would be: In a signaled environment the LSP from A1 to Z9 would be initiated
with a label request from A1 to Z9 with the fields of the FEC 129
completed as follows:
AGI::A1-{ICC::Node_ID::AC_ID}::Z9-{ICC::Node_ID::AC_ID} AGI = AGI
SAAI = A1-{Global_ID::Node_ID::AC_ID}
TAII = Z9-{Global_ID::Node_ID::AC_ID}
The LSP from Z9 to A1 would signaled with:
AGI = AGI
SAAI = Z9-{Global_ID::Node_ID::AC_ID}
TAII = A1-{Global_ID::Node_ID::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 a Maintenance maintenance points. A maintenance point is either a Maintenance
Entity Group End-point (MEP) or a Maintenance Entity Group Entity Group End-point (MEP) or a Maintenance Entity Group
Intermediate Point (MIP). Maintenance points are uniquely associated Intermediate Point (MIP). Maintenance points are uniquely associated
with a MEG. Within the context of a MEG, MEPs and MIPs must be with a MEG. Within the context of a MEG, MEPs and MIPs must be
uniquely identified. This section defines a means of uniquely uniquely identified. This section defines a means of uniquely
identifying Maintenance Entity Groups, Maintenance Entities and identifying Maintenance Entity Groups, Maintenance Entities and
uniquely defining MEPs and MIPs within the context of a Maintenance uniquely defining MEPs and MIPs within the context of a Maintenance
Entity Group. Entity Group.
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 sections, LSPs and Pseudowires. Two classes of MEG_IDs are MPLS-TP sections, LSPs and Pseudowires. The formats were chosen to
defined, one that follows the IP compatible identifier defined above follow the IP compatible identifiers defined above.
as well as the ICC-format.
7.1.1. ICC-based MEG Identifiers
MEG_ID for MPLS-TP LSPs and Pseudowires MAY use the globally unique
ICC-based format.
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.
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
unique within the organization identified by the ICC.
The ICC MEG_ID may be applied equally to a single MPLS-TP LSP or
Pseudowires. Note that when encoded in a protocol such as in a TLV,
a different type needs to be defined for LSP and PWs as the OAM
capabilities may be different.
7.1.2. IP Compatible MEG_IDs
7.1.2.1. MPLS-TP Section MEG_IDs 7.1.1. MPLS-TP Section MEG_IDs
IP compatible MEG_IDs for MPLS-TP sections are formed by IP compatible MEG_IDs for MPLS-TP sections are formed by
concatenating the two IF_IDs of the corresponding section. For concatenating the two IF_IDs of the corresponding section using the
example: A1/Z9 ordering. For example:
A1-IF_ID::Z9-IF_ID A1-IF_ID::Z9-IF_ID
Where the LSP_ID needs to be globally unique, this is accomplished by Where the Section_MEG_ID needs to be globally unique, this is
using globally unique Node_IDs as defined above. Thus a globally accomplished by using globally unique Node_IDs as defined above.
unique Section MEG_ID becomes: Thus a globally unique Section_MEG_ID becomes:
A1-{Global_ID::IF_ID}::Z9-{Global_Id::IF_ID} A1-{Global_ID::IF_ID}::Z9-{Global_ID::IF_ID}
7.1.2.2. MPLS-TP LSP MEG_IDs 7.1.2. MPLS-TP LSP MEG_IDs
Since a MEG pertains to a single MPLS-TP LSP, IP compatible MEG_IDs A MEG pertains to a unique MPLS-TP LSP. IP compatible MEG_IDs for
for MPLS-TP LSPs are simply the corresponding LSP_IDs. We note that MPLS-TP LSPs are simply the corresponding LSP_IDs, however, the the
while the two identifiers are syntactically identical, they have A1/Z9 ordering MUST be used. For bidirectional co-routed LSPs the
different semantics. This semantic difference needs to be made format of the LSP_ID is found in Section 5.2.1. For associated
clear. For instance if both a MPLS-TP LSP_ID and MPLS-TP LSP MEG_IDs bidirectional LSPs the format is in Section 5.2.2.
are to be encoded in TLVs, different types need to be assigned for
these two identifiers.
7.1.2.3. Pseudowire MEG_IDs We note that while the two identifiers are syntactically identical,
they have different semantics. This semantic difference needs to be
made clear. For instance if both a MPLS-TP LSP_ID and MPLS-TP LSP
MEG_IDs are to be encoded in TLVs, different types need to be
assigned for these two identifiers.
7.1.3. Pseudowire MEG_IDs
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, however, the
while the two identifiers are syntactically identical, they have the A1/Z9 ordering MUST be used. The PW_Path_ID is described in
different semantics. This semantic difference needs to be made Section 6. We note that while the two identifiers are syntactically
clear. For instance if both a PW_Path_ID and a PW_MEG_ID are to be identical, they have different semantics. This semantic difference
encoded in TLVs, different types need to be assigned for these two needs to be made clear. For instance if both a PW_Path_ID and a
identifiers. PW_MEG_ID are to be encoded in TLVs, different types need to be
assigned for these two identifiers.
7.2. MEP_IDs 7.2. MEP_IDs
7.2.1. ICC-based MEP Identifiers 7.2.1. MPLS-TP LSP_MEP_ID
ICC-based MEP_IDs for MPLS-TP LSPs and Pseudowires are formed by
appending a unique number to the MEG_ID defined in 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
MEP_Index is administratively assigned. It is encoded as a 16-bit
unsigned integer and MUST be unique within the MEG. An ICC-based
MEP_ID is:
MEG_ID::MEP_Index
An ICC-based MEP ID is globally unique by construction given the ICC-
based MEG_ID global uniqueness.
7.2.2. IP based MEP_IDs
7.2.2.1. MPLS-TP LSP_MEP_ID
In order to automatically generate MEP_IDs for MPLS-TP LSPs, we use In order to automatically generate MEP_IDs for MPLS-TP LSPs, we use
the elements of identification that are unique to an endpoint. This the elements of identification that are unique to an endpoint. This
ensures that MEP_IDs are unique for all LSPs within a operator. When ensures that MEP_IDs are unique for all LSPs within a operator. When
Tunnels or LSPs cross operator boundaries, these are made unique by Tunnels or LSPs cross operator boundaries, these are made unique by
pre-pending them with the operator's Global_ID. pre-pending them with the operator's Global_ID.
The MPLS-TP LSP_MEP_ID is The MPLS-TP LSP_MEP_ID is
Node_ID::Tunnel_Num::LSP_Num Node_ID::Tunnel_Num::LSP_Num
skipping to change at page 16, line 21 skipping to change at page 14, line 5
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. In the case of Tunnel_Num is the tunnel number unique to that node. In the case of
co-routed bidirectional LSPs, the single LSP_Num is used at both co-routed bidirectional LSPs, the single LSP_Num is used at both
ends. In the case of associated bidirectional LSPs, the LSP_Num is ends. In the case of associated bidirectional LSPs, the LSP_Num is
the one unique to where the MEP resides. the one unique to where the MEP resides.
In situations where global uniqueness is required this becomes: In situations where global uniqueness is required this becomes:
Global_ID::Node_ID::Tunnel_Num::LSP_Num Global_ID::Node_ID::Tunnel_Num::LSP_Num
7.2.2.2. MEP_IDs for Pseudowires 7.2.2. 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 a Pseudowire T-PE takes the form
AGI:Global_ID::Node_ID::AC_ID, AGI::Global_ID::Node_ID::AC_ID
where the Node_ID is the node in which the MEP is located and the where the Node_ID is the node in which the MEP is located and the
AC_ID is the AC_ID of the Pseudowire at that node. AC_ID is the AC_ID of the Pseudowire at that node.
7.2.2.3. Pseudowire Segments Endpoint IDs 7.3. Pseudowire Segment Endpoint IDs
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 of that same one end of a PW segment and relayed to the other end of that same
segment by setting the TTL of the PW label to one (1). For a multi- 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 segment pseudowire, TTL could be set to any value that would cause
OAM messages to reach the target segment end-point (up to and OAM messages to reach the target segment end-point (up to and
including 255). In such communications an identifier for the including 255). In such communications an identifier for the
pseudowire segment endpoint is needed. We call this a Pseudowire pseudowire segment endpoint is needed. We call this a Pseudowire
Segments Endpoint ID or PW_SE_ID. Segments Endpoint ID or PW_SE_ID.
skipping to change at page 17, line 38 skipping to change at page 15, line 25
AGI1::GID1::PE1::AII1 AGI1::GID1::PE1::AII1
The PW_SE_ID at point B would be - The PW_SE_ID at point B would be -
AGI1::GID1::PE4::AII4::GID1::PE2 AGI1::GID1::PE4::AII4::GID1::PE2
The PW_SE_ID at point C would be - The PW_SE_ID at point C would be -
AGI1::GID1::PE1::AII1::GID1::PE2 AGI1::GID1::PE1::AII1::GID1::PE2
7.3. MIP Identifiers 7.4. MIP Identifiers
At a cross-connect point, in order to automatically generate MIP_IDs 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 or PW. cross-connected via the label bindings of the MPLS-TP LSP or PW.
This allows, two MIPs to be independently identified in one node This allows, two MIPs to be independently identified in one node
where a per-interface MIP model is used. If only a per node MIP where a per-interface MIP model is used. If only a per node MIP
model is used then one MIP is configured. In this case the MIP_ID is model is used then one MIP is configured. In this case the MIP_ID is
formed using the Node_ID and an IF_Num of 0. formed using the Node_ID and an IF_Num of 0.
8. IANA Considerations 8. IANA Considerations
 End of changes. 64 change blocks. 
250 lines changed or deleted 179 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/