draft-ietf-mpls-tp-identifiers-00.txt   draft-ietf-mpls-tp-identifiers-01.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: May 14, 2010 Cisco Expires: September 9, 2010 Cisco
November 10, 2009 March 8, 2010
MPLS-TP Identifiers MPLS-TP Identifiers
draft-ietf-mpls-tp-identifiers-00 draft-ietf-mpls-tp-identifiers-01
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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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."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html. http://www.ietf.org/shadow.html.
This Internet-Draft will expire on May 14, 2010. This Internet-Draft will expire on September 9, 2010.
Copyright Notice Copyright Notice
Copyright (c) 2009 IETF Trust and the persons identified as the Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
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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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5.2. MPLS-TP LSP Identifiers . . . . . . . . . . . . . . . . . 7 5.2. MPLS-TP LSP Identifiers . . . . . . . . . . . . . . . . . 7
5.3. Mapping to GMPLS Signalling . . . . . . . . . . . . . . . 8 5.3. Mapping to GMPLS Signalling . . . . . . . . . . . . . . . 8
6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 8 6. Pseudowire Path Identifiers . . . . . . . . . . . . . . . . . 8
7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 9 7. Maintenance Identifiers . . . . . . . . . . . . . . . . . . . 9
7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 9 7.1. Maintenance Entity Group Identifiers . . . . . . . . . . . 9
7.1.1. ICC based MEG_IDs . . . . . . . . . . . . . . . . . . 9 7.1.1. ICC based MEG_IDs . . . . . . . . . . . . . . . . . . 9
7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 10 7.1.2. IP Compatible MEG_IDs . . . . . . . . . . . . . . . . 10
7.1.2.1. MPLS-TP Tunnel MEG_IDs . . . . . . . . . . . . . . 10 7.1.2.1. MPLS-TP Tunnel MEG_IDs . . . . . . . . . . . . . . 10
7.1.2.2. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 10 7.1.2.2. MPLS-TP LSP MEG_IDs . . . . . . . . . . . . . . . 10
7.1.2.3. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 10 7.1.2.3. Pseudowire MEG_IDs . . . . . . . . . . . . . . . . 10
7.2. Maintenance Points . . . . . . . . . . . . . . . . . . . . 11 7.2. MEP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 11
7.2.1. Maintenance Point_IDs for MPLS-TP LSPs and Tunnels . . 11 7.2.1. ICC based MEP_IDs . . . . . . . . . . . . . . . . . . 11
7.2.1.1. MPLS-TP Tunnel_MEP_ID . . . . . . . . . . . . . . 11 7.2.2. IP based MEP_IDs . . . . . . . . . . . . . . . . . . . 11
7.2.1.2. MPLS-TP LSP_MEP_ID . . . . . . . . . . . . . . . . 11 7.2.2.1. MEP_IDs for MPLS-TP LSPs and Tunnels . . . . . . . 11
7.2.1.3. MPLS-TP LSP_MIP_ID . . . . . . . . . . . . . . . . 11 7.2.2.2. MEP_IDs for Pseudowires . . . . . . . . . . . . . 12
7.2.2. Maintenance Identifiers for Pseudowires . . . . . . . 12 7.2.2.3. MEP_IDs for Pseudowire Segments . . . . . . . . . 12
7.2.2.1. MEP_IDs for PW T-PEs . . . . . . . . . . . . . . . 12 7.3. MIP_IDs . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.2.2.2. MP_IDs for Pseudowires . . . . . . . . . . . . . . 12
8. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 13 8. Open issues . . . . . . . . . . . . . . . . . . . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13
9.1. Normative References . . . . . . . . . . . . . . . . . . . 13 9.1. Normative References . . . . . . . . . . . . . . . . . . . 13
9.2. Informative References . . . . . . . . . . . . . . . . . . 14 9.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
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). where Transport Profile of Multiprotocol Label Switching (MPLS-TP). The
compatibility with existing MPLS control plane conventions are MPLS-TP requirements [12] require that the elements and objects in an
necessary. The MPLS-TP requirements [13] require that the elements MPLS-TP environment are able to be configured and managed without a
and objects in an MPLS-TP environment are able to be configured and control plane. In such an environment many conventions for defining
managed without a control plane. In such an environment many identifiers are possible. This document defines identifiers for
conventions for defining identifiers are possible. In particular, MPLS-TP management and OAM functions suitable to ITU conventions and
identifiers conformant to existing ITU conventions are defined. It to IP/MPLS conventions. Applicability of the different identifier
is also anticipated that operational environments where MPLS-TP schemas to different applications are outside the scope of this
objects, e.g. Label Switched Paths (LSPs) and Pseudowires (PWs) will document.
be signaled via existing protocols such as the Label Distribution
Protocol (RFC 4447) [1] and the Resource Reservation Protocol as it
is applied to Generalized Multi-protocol Label Switching (RFCs 3471 &
3473) [2][3] (GMPLS). This document defines a set of identifiers for
MPLS-TP which are both compatible with those protocols and applicable
to MPLS-TP management and OAM functions.
1.1. Terminology 1.1. Terminology
AII: Attachment Interface Identifier AII: Attachment Interface Identifier
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
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ICC: ITU Carrier Code ICC: ITU Carrier Code
LSP: Label Switched Path LSP: Label Switched Path
LSR: Label Switching Router LSR: Label Switching Router
ME: Maintenance Entity ME: Maintenance Entity
MEG: Maintenance Entity Group MEG: Maintenance Entity Group
MEP: Maintenance End Point MEP: Maintenance Entity Group End Point
MIP: Maintenance Intermediate Point MIP: Maintenance Entity Group Intermediate Point
MPLS: Multi-Protocol Label Switching MPLS: Multi-Protocol Label Switching
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
PSC: Protection State Coordination PSC: Protection State Coordination
PW: Pseudowire PW: Pseudowire
RSVP: Resource Reservation Protocol RSVP: Resource Reservation Protocol
RSVP-TE: RSVP Traffic Engineering RSVP-TE: RSVP Traffic Engineering
S-PE: Switching Provider Edge S-PE: Switching Provider Edge
T-PE: Terminating Provider Edge T-PE: Terminating Provider Edge
Requirements Language Requirements Language
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RSVP-TE: RSVP Traffic Engineering RSVP-TE: RSVP Traffic Engineering
S-PE: Switching Provider Edge S-PE: Switching Provider Edge
T-PE: Terminating Provider Edge T-PE: Terminating Provider Edge
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [4]. document are to be interpreted as described in RFC 2119 [1].
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 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)
[5] where it is used to describe an entity that provides an LSP [2] where it is used to describe an entity that provides an LSP
connection between a source and destination LSR which in turn is connection between a source and destination LSR which in turn is
instantiated by one or more LSPs, where the additional LSPs are used instantiated by one or more LSPs, where the additional LSPs are used
for protection or re-grooming of the tunnel. for protection or re-grooming of the tunnel.
3. Uniquely Identifying an Operator 3. Uniquely Identifying an Operator
Two forms of identification are defined, one that is compatible with Two forms of identification are defined, one that is compatible with
IP operational practice called a Global_ID and one compatible with IP operational practice called a Global_ID and one compatible with
ITU practice, the ICC. An Operator MAY be identified either by its ITU practice, the ICC. An Operator MAY be identified either by its
Global_ID or by its ICC. Global_ID or by its ICC.
3.1. The Global ID 3.1. The Global ID
RFC 5003 [6] 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."
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In existing MPLS deployments Node_IDs are IPv4 addresses. Therefore In existing MPLS deployments Node_IDs are IPv4 addresses. Therefore
we have chosen the Node_ID to be a 32-bit value assigned by the we have chosen the Node_ID to be a 32-bit value assigned by the
operator. Where IPv4 addresses are in use the Node_ID can be operator. Where IPv4 addresses are in use the Node_ID can be
automatically mapped to the LSR's /32 IPv4 loopback address. Note automatically mapped to the LSR's /32 IPv4 loopback address. Note
that, when IP reachability is not needed, the 32-bit Node_ID is not that, when IP reachability is not needed, the 32-bit Node_ID is not
required to have any association with the IPv4 address space used in required to have any association with the IPv4 address space used in
the operator's IGP or BGP, other that that they be uniquely chosen the operator's IGP or BGP, other that that they be uniquely chosen
within the scope of that operator. within the scope of that operator.
GMPLS signaling [2] requires interface identification. We have GMPLS signaling [4] requires interface identification. We have
chosen to adopt the conventions of that RFC. GMPLS allows three chosen to adopt the conventions of that RFC. GMPLS allows three
formats for the Interface_ID. For IP numbered links, it is simply formats for the Interface_ID. For IP numbered links, it is simply
the IPv4 or IPv6 address associated with the interface. The third the IPv4 or IPv6 address associated with the interface. The third
format consists of an IPv4 Address plus a 32-bit unsigned integer for format consists of an IPv4 Address plus a 32-bit unsigned integer for
the specific interface. the specific interface.
For MPLS-TP, we have adopted a format consistent with the third For MPLS-TP, we have adopted a format consistent with the third
format above. In MPLS-TP, each interface is assigned a 32-bit format above. In MPLS-TP, each interface is assigned a 32-bit
identifier which we call a Logical Interface Handle (LIH). The LIH identifier which we call a Logical Interface Handle (LIH). The LIH
MUST be unique within the context of the Node_ID. We map the Node_ID MUST be unique within the context of the Node_ID. We map the Node_ID
to the field the field which carries the IP address. That is, an to the field the field which carries the IP address. That is, an
IF_ID is a 64-bit identifier consisting of the Node_ID followed by IF_ID is a 64-bit identifier consisting of the Node_ID followed by
the LIH. The LIH in turn is a 32-bit unsigned integer unique to the the LIH. The LIH in turn is a 32-bit unsigned integer unique to the
node. The LIH value 0 has special meaning (see section node. The LIH value 0 has special meaning (see section Section 7.3
Section 7.2.1.3 and must not be used as the LIH in an MPLS-TP IF_ID. and must not be used as the LIH in an MPLS-TP IF_ID.
In situations where a Node_ID or an IF_ID needs to be globally In situations where a Node_ID or an IF_ID needs to be globally
unique, this is accomplished by prefixing the identifier with the unique, this is accomplished by prefixing the identifier with the
operator's Global_ID. The combination of Global_ID::Node_ID we call operator's Global_ID. The combination of Global_ID::Node_ID we call
an Global Node ID or Global_Node_ID. Likewise, the combination of an Global Node ID or Global_Node_ID. Likewise, the combination of
Global_ID::Node_ID::LIH we call an Global Interface ID or Global_ID::Node_ID::LIH we call an Global Interface ID or
Global_IF_ID. Global_IF_ID.
MPLS-TP Tunnels (see section Section 5.1) also need interface MPLS-TP Tunnels (see section Section 5.1) also need interface
identifiers. A procedure for automatically generating these is identifiers. A procedure for automatically generating these is
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Src-Global_ID::Src-Node_ID::Src-Tunnel_Num:: Dst-Global_ID::Dst- Src-Global_ID::Src-Node_ID::Src-Tunnel_Num:: Dst-Global_ID::Dst-
Node_ID::Dst-Tunnel_Num::LSP_Num Node_ID::Dst-Tunnel_Num::LSP_Num
5.3. Mapping to GMPLS Signalling 5.3. Mapping to GMPLS Signalling
This section defines the mapping from an MPLS-TP LSP_ID to GMPLS. At This section defines the mapping from an MPLS-TP LSP_ID to GMPLS. At
this time, GMPLS has yet to be extended to accommodate Global_IDs. this time, GMPLS has yet to be extended to accommodate Global_IDs.
Thus a mapping is only made for the network unique form of the Thus a mapping is only made for the network unique form of the
LSP_ID. LSP_ID.
GMPLS signaling [3] 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 = Dst-Node_ID
o Tunnel_ID = Src-Tunnel_Num o Tunnel_ID = Src-Tunnel_Num
o Extended Tunnel_ID = Src-Node_ID o Extended Tunnel_ID = Src-Node_ID
o Tunnel Sender Address = Src-Node_ID o Tunnel Sender Address = Src-Node_ID
o LSP_ID = LSP_Num o LSP_ID = LSP_Num
6. Pseudowire Path Identifiers 6. Pseudowire Path Identifiers
Pseudowire signaling (RFC 4447 [1]) 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 [6] 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 or PW_Path_Id. Identifiers, we call this a Pseudowire Path Identifier or 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.
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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::Dst- AGI:Src-Global_ID::Src-Node_ID::Src-AC_ID:: Dst-Global_ID::Dst-
Node_ID::Dst-AC_ID. Node_ID::Dst-AC_ID.
7. Maintenance Identifiers 7. Maintenance Identifiers
[Note this section needs to reconciled with on going ITU and MPLS WG [Note this section needs to reconciled with the MPLS-TP OAM
discussions on Maintenance Points.] Framework]
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 End- maintenance points. A maintenance point is either Maintenance Entity
point (MEP) or a Maintenance Intermediate Point (MIP). A Maintenance Group End-point (MEP) or a Maintenance Entity Group Intermediate
Entity is a relationship between two MEPs. This section defines a Point (MIP). Maintenance points are uniquely associated with a MEG.
means of uniquely identifying Maintenance Entity Groups, Maintenance Within the context of a MEG, MEPs and MIPs must be uniquely
Entities and uniquely defining MEPs and MIPs within the context of a identified. This section defines a means of uniquely identifying
Maintenance Entity Group. Maintenance Entity Groups, Maintenance Entities and uniquely defining
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 Paths and Pseudowires. Two classes of MEG_IDs are defined, MPLS-TP Paths and Pseudowires. Two classes of MEG_IDs are defined,
one that follows the IP compatible identifier defined above as well one that follows the IP compatible identifier defined above as well
as the ICC-format. as the ICC-format.
7.1.1. ICC based MEG_IDs 7.1.1. ICC based MEG_IDs
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7.1.2.3. Pseudowire MEG_IDs 7.1.2.3. 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. We note that
while the two identifiers are syntactically identical, they have while the two identifiers are syntactically identical, they have
different semantics. This semantic difference needs to be made different semantics. This semantic difference needs to be made
clear. For instance if both a PW_Path_ID and a PW_MEG_ID is to be clear. For instance if both a PW_Path_ID and a PW_MEG_ID is to be
encoded in TLVs different types need to be assigned for these two encoded in TLVs different types need to be assigned for these two
identifiers. identifiers.
7.2. Maintenance Points 7.2. MEP_IDs
Maintenance points are uniquely associated with a MEG. Within the 7.2.1. ICC based MEP_IDs
context of a MEG, MEPs and MIPs must be uniquely identified. This
section describes how MIPs and MEPs are identified.
Note that depending on the requirements of a particular OAM ICC-based MEP_IDs for MPLS-TP LSPs and Pseudowires MAY be formed by
interaction, the MPLS-TP maintenance entity context may be provided appending a unique number to the MEG_ID defined in section
either explicitly using the MEG_IDs described above or implicitly by Section 7.1.1 above. Within the context of a particular MEG, we call
the label of the received OAM message. the identifier associated with a MEP the MEP Index (MEP_Index). The
MEP_Index is administratively assigned and is encoded as a 16-bit
unsigned integer. An ICC-based MEP_ID is:
7.2.1. Maintenance Point_IDs for MPLS-TP LSPs and Tunnels 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. MEP_IDs for MPLS-TP LSPs and Tunnels
In order to automatically generate MEP_IDs for MPLS-TP Tunnels and In order to automatically generate MEP_IDs for MPLS-TP Tunnels and
LSPs, we use the elements of identification that are unique to an LSPs, we use the elements of identification that are unique to an
endpoint. This ensures that MEP_IDs are unique for all Tunnels and endpoint. This ensures that MEP_IDs are unique for all Tunnels and
LSPs within a operator. When Tunnels or LSPs cross operator LSPs within a operator. When Tunnels or LSPs cross operator
boundaries, these are made unique by pre-pending them with the boundaries, these are made unique by pre-pending them with the
operator's Global_ID. operator's Global_ID.
7.2.1.1. MPLS-TP Tunnel_MEP_ID 7.2.2.1.1. MPLS-TP Tunnel_MEP_ID
A MPLS-TP Tunnel_MEP_ID is: A MPLS-TP Tunnel_MEP_ID is:
Src-Node_ID::Src-Tunnel_Num Src-Node_ID::Src-Tunnel_Num
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 Src-Global_ID::Src-Node_ID::Src-Tunnel_Num
7.2.1.2. MPLS-TP LSP_MEP_ID 7.2.2.1.2. MPLS-TP LSP_MEP_ID
A MPLS-TP LSP_MEP_ID is: A MPLS-TP LSP_MEP_ID is:
Src-Node_ID::Src-Tunnel_Num::LSP_Num Src-Node_ID::Src-Tunnel_Num::LSP_Num
In situations where global uniqueness is required this becomes: In situations where global uniqueness is required this becomes:
Src-Global_ID::Src-Node_ID::Src-Tunnel_Num::LSP_Num Src-Global_ID::Src-Node_ID::Src-Tunnel_Num::LSP_Num
7.2.1.3. MPLS-TP LSP_MIP_ID 7.2.2.2. MEP_IDs for Pseudowires
At a cross connect point, in order to automatically generate MIP_IDs
for MPLS-TP LSPs, 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 one MIP is configured, then the MIP_ID is formed using the
Node_ID and an LIH of 0.
7.2.2. Maintenance Identifiers for Pseudowires
Like MPLS-TP LSPs, Pseudowire endpoints (T-PEs) require MEP-IDs.
Pseudowire S-PEs, however, are a special case. Here the Maintenance
Entity takes on some of the functionality of both a MIP and a MEP.
Provisionally we are calling these a Maintenance Point or MP.
7.2.2.1. MEP_IDs for PW T-PEs
In order to automatically generate MEP_IDs for PWs, we simply use the Like MPLS-TP LSPs, Pseudowire endpoints (T-PEs) require MEP_IDs. In
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
for an Pseudowire T-PE takes the form: used in end-to-end for an Pseudowire T-PE takes the form:
AGI:Src-Global_ID::Src-Node_ID::Src-AC_ID AGI:Src-Global_ID::Src-Node_ID::Src-AC_ID
7.2.2.2. MP_IDs for Pseudowires 7.2.2.3. MEP_IDs for Pseudowire Segments
The MP_ID is formed by a combination of a PW MEP_ID and the In some OAM communications, messages are originated at one end of a
PW segment and relayed to the other end by setting the TTL of the PW
label to one.
The MEP_ID Is Formed by a combination of a PW MEP_ID and the
identification of the local node. At an S-PE, there are two PW identification of the local node. At an S-PE, there are two PW
segments. We distinguish the segments by using the MEP-ID which is segments. We distinguish the segments by using the MEP_ID which is
upstream of the PW segment in question. To complete the upstream of the PW segment in question. To complete the
identification we suffix this with the identification of the local identification we suffix this with the identification of the local
node. node.
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
| | | | | | | | | | | | | | | |
| A|---------|B C|---------|D E|---------|F | | A|---------|B C|---------|D E|---------|F |
| | | | | | | | | | | | | | | |
+-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+ +-------+
T-PE1 S-PE2 S-PE3 T-PE4 T-PE1 S-PE2 S-PE3 T-PE4
skipping to change at page 13, line 7 skipping to change at page 13, line 7
Src-Node_ID = T-PE1 Src-Node_ID = T-PE1
Src-AC_ID = AII1 Src-AC_ID = AII1
Dst-Global_ID = GID1 Dst-Global_ID = GID1
Dst-Node_ID = T-PE1 Dst-Node_ID = T-PE1
Dst-AC_ID = AII4 Dst-AC_ID = AII4
The MEP_ID at point A would be AGI1::GID1:T-PE1::AII1. The MP_ID at The MEP_ID at point A would be AGI1::GID1:T-PE1::AII1. The MP_ID at
point C would be AGI1::GID1:T-PE1::AII1::GID1:S-PE2. point C would be AGI1::GID1:T-PE1::AII1::GID1:S-PE2.
For interaction where the T-PE is acting as the segment endpoint, it For interaction where the T-PE is acting as the segment endpoint, it
too may use the MP_ID. too may use the Pseudowire Segment MEP_ID.
8. Open issues
1. We have two means of identifying operators. Should either be 7.3. MIP_IDs
allowed in all cases or can we constrain this. I.e. when there
are both IP compatible and ITU compatible IDs for an Object can
we constrain the operator ID to the corresponding format?
Clearly when only one identifier is defined the both must be
allowed.
2. Details on MEP and MIP identifiers are subject to ongoing At a cross connect point, in order to automatically generate MIP_IDs
discussions. Further based on some discussion in Stockholm, ITU for MPLS-TP, we simply use the IF_IDs of the two interfaces which are
style identifiers for MEPs and MIPs were removed from this cross connected via the label bindings of the MPLS-TP LSP. If only
version. However, consensus for this needs to be verified. one MIP is configured, then the MIP_ID is formed using the Node_ID
and an LIH of 0. In some contexts, such as LSP Ping[13], the Node_ID
alone may be used as the MEP_ID.
3. Pseudowire Maintenance Points need to be kept aligned with the 8. Open issues
model for Pseudowire maintenance.
4. Identifiers for P2MP entities 1. MEPs and MIPs need to be aligned with MPLS-TP OAM Framework.
5. Tandem connection Identification - the identification should be 2. Identifiers for P2MP entities.
exactly the same as any other MPLS-TP LSP. However, in the ACH
TLV draft we could have a different TLV with the same format as
an MPLS-TP LSP, if there are places where the distinction becomes
important.
9. References 9. References
9.1. Normative References 9.1. Normative References
[1] Martini, L., Rosen, E., El-Aawar, N., Smith, T., and G. Heron, [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement
"Pseudowire Setup and Maintenance Using the Label Distribution
Protocol (LDP)", RFC 4447, April 2006.
[2] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS)
Signaling Functional Description", RFC 3471, January 2003.
[3] Berger, L., "Generalized Multi-Protocol Label Switching (GMPLS)
Signaling Resource ReserVation Protocol-Traffic Engineering
(RSVP-TE) Extensions", RFC 3473, January 2003.
[4] 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.
[5] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and [2] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., and
G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels", G. Swallow, "RSVP-TE: Extensions to RSVP for LSP Tunnels",
RFC 3209, December 2001. RFC 3209, December 2001.
[6] Metz, C., Martini, L., Balus, F., and J. Sugimoto, "Attachment [3] Metz, C., Martini, L., Balus, F., and J. Sugimoto, "Attachment
Individual Identifier (AII) Types for Aggregation", RFC 5003, Individual Identifier (AII) Types for Aggregation", RFC 5003,
September 2007. 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 [7] Kompella, K., Rekhter, Y., and A. Kullberg, "Signalling
Unnumbered Links in CR-LDP (Constraint-Routing Label Unnumbered Links in CR-LDP (Constraint-Routing Label
Distribution Protocol)", RFC 3480, February 2003. Distribution Protocol)", RFC 3480, February 2003.
[8] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in [8] Kompella, K., Rekhter, Y., and L. Berger, "Link Bundling in
MPLS Traffic Engineering (TE)", RFC 4201, October 2005. MPLS Traffic Engineering (TE)", RFC 4201, October 2005.
[9] Kompella, K. and G. Swallow, "Detecting Multi-Protocol Label [9] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
Switched (MPLS) Data Plane Failures", RFC 4379, February 2006.
[10] Lang, J., Rekhter, Y., and D. Papadimitriou, "RSVP-TE
Extensions in Support of End-to-End Generalized Multi-Protocol Extensions in Support of End-to-End Generalized Multi-Protocol
Label Switching (GMPLS) Recovery", RFC 4872, May 2007. Label Switching (GMPLS) Recovery", RFC 4872, May 2007.
[11] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "BFD [10] Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow, "BFD
For MPLS LSPs", draft-ietf-bfd-mpls-07 (work in progress), For MPLS LSPs", draft-ietf-bfd-mpls-07 (work in progress),
June 2008. June 2008.
[12] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding [11] Nadeau, T. and C. Pignataro, "Bidirectional Forwarding
Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Detection (BFD) for the Pseudowire Virtual Circuit Connectivity
Verification (VCCV)", draft-ietf-pwe3-vccv-bfd-07 (work in Verification (VCCV)", draft-ietf-pwe3-vccv-bfd-07 (work in
progress), July 2009. progress), July 2009.
9.2. Informative References 9.2. Informative References
[13] Vigoureux, M., Ward, D., and M. Betts, "Requirements for OAM in [12] Vigoureux, M. and D. Ward, "Requirements for OAM in MPLS
MPLS Transport Networks", Transport Networks", draft-ietf-mpls-tp-oam-requirements-06
draft-ietf-mpls-tp-oam-requirements-03 (work in progress), (work in progress), March 2010.
August 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 [14] Ohta, H., "Assignment of the 'OAM Alert Label' for
Multiprotocol Label Switching Architecture (MPLS) Operation and Multiprotocol Label Switching Architecture (MPLS) Operation and
Maintenance (OAM) Functions", RFC 3429, November 2002. Maintenance (OAM) Functions", RFC 3429, November 2002.
[15] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and [15] Niven-Jenkins, B., Brungard, D., Betts, M., Sprecher, N., and
S. Ueno, "MPLS-TP Requirements", S. Ueno, "MPLS-TP Requirements",
draft-ietf-mpls-tp-requirements-10 (work in progress), draft-ietf-mpls-tp-requirements-10 (work in progress),
August 2009. August 2009.
[16] Bocci, M., Bryant, S., Frost, D., and L. Levrau, "A Framework [16] Bocci, M., Bryant, S., Frost, D., Levrau, L., and L. Berger, "A
for MPLS in Transport Networks", Framework for MPLS in Transport Networks",
draft-ietf-mpls-tp-framework-06 (work in progress), draft-ietf-mpls-tp-framework-10 (work in progress),
October 2009. February 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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