draft-ietf-mpls-tp-identifiers-03.txt   draft-ietf-mpls-tp-identifiers-04.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: April 28, 2011 Cisco Expires: September 4, 2011 Cisco
E. Gray E. Gray
Ericsson Ericsson
October 25, 2010 March 3, 2011
MPLS-TP Identifiers MPLS-TP Identifiers
draft-ietf-mpls-tp-identifiers-03 draft-ietf-mpls-tp-identifiers-04
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
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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 April 28, 2011. This Internet-Draft will expire on September 4, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 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
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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
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the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
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1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4 1.2. Requirements Language . . . . . . . . . . . . . . . . . . 4
1.3. Notational Conventions in Backus-Naur Form . . . . . . . . 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 . . . . . . . . . . . . . . . . . . . . . 6 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 . . . . . . . . 8 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 . . . . . . . . . . . . . . . 9 5.2.1. MPLS-TP Co-Routed Bidirectional LSP Identifiers . . . 8
6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 9 5.2.2. MPLS-TP Associated Bidirectional LSP Identifiers . . . 9
7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 10 5.3. Mapping to GMPLS and RSVP-TE Signalling . . . . . . . . . 9
7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 10 6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 10
7.1.1. ICC-based MEG Identifiers . . . . . . . . . . . . . . 10 7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 11
7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 11 7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 11
7.1.2.1. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 11 7.1.1. ICC-based MEG Identifiers . . . . . . . . . . . . . . 12
7.1.2.2. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 11 7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 12
7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 11 7.1.2.1. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 12
7.2.1. ICC-based MEP Identifiers . . . . . . . . . . . . . . 11 7.1.2.2. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 12
7.2.2. IP based MEP_IDs . . . . . . . . . . . . . . . . . . . 12 7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.2.2.1. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . 12 7.2.1. ICC-based MEP Identifiers . . . . . . . . . . . . . . 12
7.2.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . 12 7.2.2. IP based MEP_IDs . . . . . . . . . . . . . . . . . . . 13
7.2.2.3. Endpoint IDs Pseudowire Segments . . . . . . . . . 12 7.2.2.1. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . 13
7.3. MIP Identifiers . . . . . . . . . . . . . . . . . . . . . 13 7.2.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . 13
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 7.2.2.3. Pseudowire Segments Endpoint IDs . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 14 7.3. MIP Identifiers . . . . . . . . . . . . . . . . . . . . . 14
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . . 14 9. Security Considerations . . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . . 15 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 10.1. Normative References . . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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 (RFC 5654) [12] require that the elements and MPLS-TP requirements (RFC 5654) [7] require that the elements and
objects in an MPLS-TP environment are able to be configured and objects in an MPLS-TP environment are able to be configured and
managed without a control plane. In such an environment many managed without a control plane. In such an environment many
conventions for defining identifiers are possible. This document conventions for defining identifiers are possible. This document
defines identifiers for MPLS-TP management and OAM functions suitable defines identifiers for MPLS-TP management and OAM functions suitable
to ITU conventions and to IP/MPLS conventions. Applicability of the to ITU conventions and to IP/MPLS conventions. Applicability of the
different identifier schemas to different applications are outside different identifier schemas to different applications is outside the
the scope of this document. scope of this document.
1.1. Terminology 1.1. Terminology
AII: Attachment Interface Identifier AII: Attachment Interface Identifier
AP: Attachment Point
ASN: Autonomous System Number ASN: Autonomous System Number
FEC: Forwarding Equivalence Class FEC: Forwarding Equivalence Class
GMPLS: Generalized Multi-Protocol Label Switching GMPLS: Generalized Multi-Protocol Label Switching
ICC: ITU Carrier Code ICC: ITU Carrier Code
LSP: Label Switched Path LSP: Label Switched Path
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ME: Maintenance Entity 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
OAM: Operations, Administration and Maintenance OAM: Operations, Administration and Maintenance
P2MP: Point to Multi-Point 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
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1.3. 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 concatenation of other identifiers. These are expressed using
Backus-Naur Form (using double-colon - "::" - notation). Backus-Naur Form (using double-colon - "::" - notation).
Where the same identifier type is used multiple times in a Where the same identifier type is used multiple times in a
concatenation, they are qualified by a prefix joined to the 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 East-Node_ID is the Node_ID of
a node referred to as Src (where "Src" is short for "source" in this a node referred to as East.
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
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o Operator o Operator
* Global_ID * Global_ID
* ICC * ICC
o LSR o LSR
o LSP o LSP
o PW o PW
o Interface o Interface
o MEG o MEG
o MEP o MEP
o MIP o MIP
o Tunnel o 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 connection [2] where it is used to describe an entity that provides a logical
between a source and destination LSR. The tunnel in turn is association between a source and destination LSR. The tunnel in turn
instantiated by one or more LSPs, where the additional LSPs are used is instantiated by one or more LSPs, where the additional LSPs are
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
Two forms of identification are defined, one that is compatible with An operator is uniquely identified by an Operator Identifier
IP operational practice called a Global_ID and one compatible with (Opr_ID). Two formats are defined, one that is compatible with IP
ITU practice, the ICC. An Operator MAY be identified either by operational practice called a Global_ID and or one compatible with
Global_ID or by ICC. ITU practice, the ICC. An The Opr_ID MAY use either the Global_ID or
ICC format.
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
derived from the globally unique ASN of the autonomous system hosting derived from the globally unique ASN of the autonomous system hosting
the PEs containing the actual AIIs. The presence of a global ID the PEs containing the actual AIIs. The presence of a global ID
based on the operator's ASN ensures that the AII will be globally based on the operator's ASN ensures that the AII will be globally
unique." unique."
When the Global_ID is derived from a 2-octet AS number, the two high- When the Global_ID is derived from a 2-octet AS number, the two high-
order octets of this 4-octet identifier MUST be set to zero. order octets of this 4-octet identifier MUST be set to zero. Further
ASN 0 is reserved. A Global_ID of zero means that no Global_ID is
present. Note that a Global_ID of zero is limited to entities
contained within a single operator and MUST NOT be used across an
NNI. A non-zero Global_ID MUST be derived from an ASN owned by the
operator.
Note that this Global_ID is used solely to provide a globally unique Note that this Global_ID is used solely to provide a globally unique
context for other MPLS-TP identifiers. It has nothing to do with the context for other MPLS-TP identifiers. It has nothing to do with the
use of the ASN in protocols such as BGP. use of the ASN in protocols such as BGP.
3.2. ITU Carrier Code 3.2. ITU Carrier Code
M.1400 defines the ITU Carrier Code (ICC) assigned to a network M.1400 defines the ITU Carrier Code (ICC) assigned to a network
operator/service provider and maintained by the ITU-T operator/service provider and maintained by the ITU-T
Telecommunication Standardization Bureau (TSB): www.itu.int/ITU-T/ Telecommunication Standardization Bureau (TSB): www.itu.int/ITU-T/
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kinds. kinds.
The ICC is a string of one to six characters, each character being 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. either alphabetic (i.e. A-Z) or numeric (i.e. 0-9) characters.
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 attachment point 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 value assigned by the (Node_ID). The Node_ID is a unique 32-bit value assigned by the
operator within the scope of the Global_ID. The value zero is operator within the scope of the Global_ID. The structure of the
reserved and MUST NOT be used. Where IPv4 addresses are used, it is Node_ID is operator specific and is outside the scope of this
convenient to use the Node's IPv4 loopback address as the Node_ID, document. However, the value zero is reserved and MUST NOT be used.
however the Node_ID does not need to have any association with the Where IPv4 addresses are used, it may be convenient to use the Node's
IPv4 address space used in the operator's IGP or BGP. Where IPv6 IPv4 loopback address as the Node_ID, however the Node_ID does not
addresses are used exclusively, a domain unique 32- bit value is need to have any association with the IPv4 address space used in the
assigned operator's IGP or BGP. Where IPv6 addresses are used exclusively, a
32-bit value unique within the scope of the Global_ID is assigned.
A LSR can support multiple layers (e.g. hierarchical LSPs) and the
Node_ID belongs to the multiple layer context i.e. it is applicable
to all LSPs or PWs that originate on, have a midpoint on, 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 Opr_ID.
Global_ID. The combination of Global_ID::Node_ID we call an Global The particular combination of Global_ID::Node_ID we call a 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 and MUST NOT be used as the IF_Num in an MPLS-TP special meaning (see section , MIP Identifiers) (Section 7.3) and
IF_ID. MUST NOT be used to identify an MPLS-TP interface.
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 an Opr_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.
The format defined for MPLS-TP is consistent with this format, but The format defined for MPLS-TP is consistent with this format, but
uses the Node_ID instead of an IPv4 Address. uses the Node_ID instead of an IPv4 Address.
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. The prefixing the identifier with the operator's Opr_ID.
combination of Global_ID::Node_ID::IF_Num we call an Global Interface
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. Note that MPLS-TP supports
generating these is contained in that section. hierarchical tunnels. The attachment point to a MPLS-TP Tunnel at
any sub layer requires a unique IF_ID.
5. MPLS-TP Tunnel and LSP Identifiers 5. MPLS-TP Tunnel and LSP Identifiers
An important construct within MPLS_TP is a service that may be In MPLS the actual transport of packets is provided by label switched
identified by the server to a client, ideally using a single paths (LSPs). A transport service may be composed of multiple LSPs.
identifier. Such a service may be provided across a working and a Further the LSPs providing a service may change over time due to
protection LSP, both of which should be similarly identified. Within protection and restoration events. In order to clearly identify the
this document we will use the term "MPLS-TP Tunnel" or simply service we use the term "MPLS-TP Tunnel" or simply "tunnel" for a
"tunnel" for a service provided by (for example) a working and service provided by (for example) a working LSP and protected by a
protection LSPs. This section defines an MPLS-TP Tunnel_ID to protection LSP. The Tunnel_ID identifies the transport service and
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 and
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 MPLS-TP LSP_IDs within the context of
that tunnel. that 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 this identifier
allows for a trivial mapping between the server and client layers to allows for a trivial mapping between the server and client layers to
a common service identifier which may be either defined by, or used a common service identifier which may be either defined by, or used
by, the client. 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,
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Keeping the tunnel number consistent across working and protection Keeping the tunnel number consistent across working and protection
LSPs is a useful construct currently employed within GMPLS. However LSPs is a useful construct currently employed within GMPLS. However
there is no requirement that a protection LSP use the same tunnel there is no requirement that a protection LSP use the same tunnel
number as the working LSP. 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_ID. 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 numbers also serves to simplify other signaling
instance an associated bi-directional tunnel could be setup using two (e.g., setup of associated bi-directional tunnels as described in
unidirectional tunnels signaled via RSVP. section 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. In a signaled situation, the node originating the identifier. In a configured environment the endpoints are often
signaling exchange is called the source and the target node is called called East and West. Using this convention the format of the format
the destination. In a configured environment the endpoints could of a Tunnel_ID is:
equally be called East and West. Using the signaled convention and
abbreviating the endpoint qualifiers to Src and Dst respectively, the
format of the format of a Tunnel_ID is:
Src-Node_ID::Src-Tunnel_Num::Dst-Node_ID::Dst-Tunnel_Num East-Node_ID::East-Tunnel_Num::West-Node_ID::West-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:
Src-Global_Node_ID::Src-Tunnel_Num::Dst-Global_Node_ID:: East-Global_Node_ID::East-Tunnel_Num::West-Global_Node_ID::
Dst-Tunnel_Num West-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 both the source and destination endpoints. As usual, the IF_ID at both the source and destination endpoints. As usual, the
IF_ID is composed of the local NODE_ID concatenated with a 32-bit IF_ID is composed of the local NODE_ID concatenated with a 32-bit
IF_Num. It is RECOMMENDED that the IF_Num be auto-generated by adding IF_Num.
2^31 to the local Tunnel_Num.
5.2. MPLS-TP LSP Identifiers 5.2. MPLS-TP LSP Identifiers
Within the scope of an MPLS-TP Tunnel_ID an LSP can be uniquely 5.2.1. MPLS-TP Co-Routed Bidirectional LSP Identifiers
identified by a single LSP number. Specifically an LSP_Num is a 16-
bit unsigned integer unique within the Tunnel_ID. Thus the format of
a LSP_ID is:
Src-Node_ID::Src-Tunnel_Num::Dst-Node_ID::Dst-Tunnel_Num::LSP_Num For 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_Num is a 16-bit unsigned integer unique within
the Tunnel_ID. Thus the format of a LSP_ID is:
East-Node_ID::East-Tunnel_Num::West-Node_ID::West-
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 LSP_ID becomes:
Src-Global_Node_ID::Src-Tunnel_Num::Dst-Global_Node_ID:: East-Global_Node_ID::East-Tunnel_Num::West-Global_Node_ID::
Dst-Tunnel_Num::LSP_Num West-Tunnel_Num::LSP_Num
The corresponding ICC-based version of this identifier would be: The corresponding ICC-based version of this identifier would be:
East-ICC::East-Node_ID::East-Tunnel_Num::West-ICC::West-Node_ID::
West-Tunnel_Num::LSP_Num
Src-ICC::Src-Tunnel_Num::Dst-ICC::Dst-Tunnel_Num::LSP_Num 5.2.2. MPLS-TP Associated Bidirectional LSP Identifiers
5.3. Mapping to GMPLS Signalling For an associated bidirectional LSP each of the unidirectional LSPs
from East to West and West to East require LSP IDs. The each LSP can
be uniquely identified by a single LSP number within the scope of the
senders Tunnel_Num. Specifically an LSP_Num is a 16-bit unsigned
integer unique within the Tunnel_Num. Thus the format of a LSP_ID is:
East-Node_ID::East-Tunnel_Num::East-LSP_Num::
West-Node_ID::West-Tunnel_Num::West-LSP_Num
Where the LSP_ID needs to be globally unique, this is accomplished by
using globally unique Node_IDs as defined above. Thus a globally
unique LSP_ID becomes:
East-Global_Node_ID::East-Tunnel_Num::East-LSP_Num::
West-Global_Node_ID::West-Tunnel_Num::West-LSP_Num
The corresponding ICC-based version of this identifier would be:
East-ICC::East-Node_ID::East-Tunnel_Num::East-LSP_Num::
West-ICC::West-Node_ID::West-Tunnel_Num::West-LSP_Num
5.3. Mapping to GMPLS and RSVP-TE 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
(GMPLS) LSP_ID. (GMPLS) LSP_ID.
In situations where a mapping to the GMPLS 5-tuple is required, the In situations where a mapping to the GMPLS 5-tuple is required, the
following mapping is used. following mapping is used.
o Tunnel Endpoint Address = Dst-Node_ID o Tunnel Endpoint Address = West-Node_ID
o Tunnel_ID = Src-Tunnel_Num o Tunnel_ID = East-Tunnel_Num
o Extended Tunnel_ID = Src-Node_ID o Extended Tunnel_ID = East-Node_ID
o Tunnel Sender Address = Src-Node_ID o Tunnel Sender Address = East-Node_ID
o LSP_ID = LSP_Num o LSP_ID = East-LSP_Num
An associated bi-directional LSP between two nodes East and West
consists of two uni-directional LSPs, one from East to West and one
from West to East. RSVP-TE is capable of signaling such LSPs.
In situations where a mapping to the RSVP 5-tuples is required, the
following mappings are used. For the East to West LSP the mapping
would be:
o Tunnel Endpoint Address = West-Node_ID
o Tunnel_ID = East-Tunnel_Num
o Extended Tunnel_ID = East-Node_ID
o Tunnel Sender Address = East-Node_ID
o LSP_ID = East-LSP_Num
Likewise, the East to West LSP the mapping would be:
o Tunnel Endpoint Address = East-Node_ID
o Tunnel_ID = West-Tunnel_Num
o Extended Tunnel_ID = West-Node_ID
o Tunnel Sender Address = West-Node_ID
o LSP_ID = West-LSP_Num
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
skipping to change at page 10, line 16 skipping to change at page 11, line 26
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::East-Global_Node_ID::East-AC_ID::West-Global_Node_ID::
Dst-Node_ID::Dst-AC_ID. West-AC_ID.
The corresponding ICC-based version for this identifier would be: The corresponding ICC-based version for this identifier would be:
AGI::Src-ICC::Src-Node_ID::Src-AC_ID::Dst-ICC::Dst-Node_ID:: AGI::East-ICC::East-Node_ID::East-AC_ID::West-ICC::West-Node_ID::
Dst-AC_ID West-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
MEPs and MIPs within the context of a Maintenance Entity Group. MEPs and MIPs within the context of a Maintenance Entity Group.
Note that depending on the requirements of a particular OAM
interaction, the MPLS-TP maintenance entity context may be provided
either explicitly using the MEG_IDs described above or implicitly by
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 Identifiers 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
skipping to change at page 12, line 21 skipping to change at page 13, line 26
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,
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. In the case of
Associated Bi-directional LSPs, the LSP_Num unique to where the MEP
resides.
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 Global_ID::Node_ID::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:Global_ID::Node_ID::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 the
Tunnel_Num is the tunnel number unique to that node. AC_ID is the AC_ID of the Pseudowire at that node.
7.2.2.3. Endpoint IDs Pseudowire Segments 7.2.2.3. Pseudowire Segments 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). including 255). In such communications an identifier for the
pseudowire segment endpoint. We call this a Pseudowire Segments
Endpoint ID or PW_SE_ID.
The MEP_ID Is Formed by a combination of a PW MEP_ID and the The PW_SE_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 East-Global_ID = GID1
Src-Node_ID = PE1 East-Node_ID = PE1
Src-AC_ID = AII1 East-AC_ID = AII1
Dst-Global_ID = GID1 West-Global_ID = GID1
Dst-Node_ID = PE4 West-Node_ID = PE4
Dst-AC_ID = AII4 West-AC_ID = AII4
The PW segment endpoint MEP_ID at point A would be - The MEP_ID at point A would be -
AGI1::GID1::PE1::AII1 AGI1::GID1::PE1::AII1
The MP_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 7.3. 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. If only cross-connected via the label bindings of the MPLS-TP LSP. This
one MIP is configured, then the MIP_ID is formed using the Node_ID allows, two MIPs to be independently identified in one node where a
and an IF_Num of 0. In some contexts, such as LSP Ping[13], the per-interface MIP model is used. If only a per node MIP model is
Node_ID alone may be used as the MIP_ID. used then one MIP is configured. In this case the MIP_ID is formed
using the Node_ID and an IF_Num of 0.
8. IANA Considerations 8. IANA Considerations
There are no IANA actions resulting from this document. 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 This document describes an information model and, as such, does not
introduce security concerns. Protocol specifications that describe introduce security concerns. Protocol specifications that describe
use of this information model - however - may introduce security use of this information model - however - may introduce security
skipping to change at page 14, line 21 skipping to change at page 15, line 29
reason, the writers of protocol specifications for the purpose of reason, the writers of protocol specifications for the purpose of
describing implementation of this information model need to describe describing implementation of this information model need to describe
security and authentication concerns that may be raised by the security and authentication concerns that may be raised by the
particular mechanisms defined and how those concerns may be particular mechanisms defined and how those concerns may be
addressed. 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
G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels",
RFC 3209, December 2001.
[3] Metz, C., Martini, L., Balus, F., and J. Sugimoto, "Attachment
Individual Identifier (AII) Types for Aggregation", RFC 5003,
September 2007.
[4] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS)
Signaling Functional Description", RFC 3471, January 2003.
[5] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS)
Signaling Resource ReserVation Protocol-Traffic Engineering
(RSVP-TE) Extensions", RFC 3473, January 2003.
[6] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G. Heron,
"Pseudowire Setup and Maintenance Using the Label Distribution
Protocol (LDP)", RFC 4447, April 2006.
[7] Kompella, K., Rekhter, Y., and A. Kullberg, "Signalling [2] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and G.
Unnumbered Links in CR-LDP (Constraint-Routing Label Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels",
Distribution Protocol)", RFC 3480, February 2003. RFC 3209, December 2001.
[8] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in [3] Metz, C., Martini, L., Balus, F., and J. Sugimoto, "Attachment
MPLS Traffic Engineering (TE)", RFC 4201, October 2005. Individual Identifier (AII) Types for Aggregation", RFC 5003,
September 2007.
[9] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE [4] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS)
Extensions in Support of End-to-End Generalized Multi-Protocol Signaling Functional Description", RFC 3471, January 2003.
Label Switching (GMPLS) Recovery", RFC 4872, May 2007.
[10] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, [5] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS)
"Bidirectional Forwarding Detection (BFD) for MPLS Label Signaling Resource ReserVation Protocol-Traffic Engineering
Switched Paths (LSPs)", RFC 5884, June 2010. (RSVP-TE) Extensions", RFC 3473, January 2003.
[11] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding [6] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G. Heron,
Detection (BFD) for the Pseudowire Virtual Circuit Connectivity "Pseudowire Setup and Maintenance Using the Label Distribution
Verification (VCCV)", RFC 5885, June 2010. Protocol (LDP)", RFC 4447, April 2006.
10.2. Informative References 10.2. Informative References
[12] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and [7] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and S.
S. Ueno, "Requirements of an MPLS Transport Profile", RFC 5654, Ueno, "Requirements of an MPLS Transport Profile", RFC 5654,
September 2009. September 2009.
[13] Kompella, K. and G. Swallow, "Detecting Multi-Protocol Label
Switched (MPLS) Data Plane Failures", RFC 4379, February 2006.
[14] Ohta, H., "Assignment of the 'OAM Alert Label' for
Multiprotocol Label Switching Architecture (MPLS) Operation and
Maintenance (OAM) Functions", RFC 3429, November 2002.
[15] Vigoureux, M., Ward, D., and M. Betts, "Requirements for
Operations, Administration, and Maintenance (OAM) in MPLS
Transport Networks", RFC 5860, May 2010.
[16] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Berger, "A
Framework for MPLS in Transport Networks", RFC 5921, July 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
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