MPLS Working Group D. Frost, Ed.
Internet-Draft Cisco Systems
Intended status: Informational M. Bocci, Ed.
Expires: January 6, 2011 Alcatel-Lucent
L. Berger, Ed.
LabN Consulting
July 5, 2010
A Framework for Point-to-Multipoint MPLS in Transport Networks
draft-fbb-mpls-tp-p2mp-framework-01
Abstract
The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP)
is the common set of MPLS protocol functions defined to enable the
construction and operation of packet transport networks. The MPLS-TP
supports both point-to-point and point-to-multipoint transport paths.
This document defines the elements and functions of the MPLS-TP
architecture applicable specifically to supporting point-to-
multipoint transport paths.
This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network.
Status of This Memo
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provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on January 6, 2011.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
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document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1. Additional Definitions and Terminology . . . . . . . . 4
1.3. Applicability . . . . . . . . . . . . . . . . . . . . . . . 4
2. MPLS Transport Profile Point-to-Multipoint Requirements . . . . 4
3. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. MPLS-TP Encapsulation and Forwarding . . . . . . . . . . . 6
4. Operations, Administration and Maintenance (OAM) . . . . . . . 6
5. Control Plane . . . . . . . . . . . . . . . . . . . . . . . . . 6
5.1. Point-to-Multipoint LSP Control Plane . . . . . . . . . . . 6
5.2. Point-to-Multipoint PW Control Plane . . . . . . . . . . . 6
6. Survivability . . . . . . . . . . . . . . . . . . . . . . . . . 7
7. Network Management . . . . . . . . . . . . . . . . . . . . . . 7
8. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
10.1. Normative References . . . . . . . . . . . . . . . . . . . 7
10.2. Informative References . . . . . . . . . . . . . . . . . . 8
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1. Introduction
The Multiprotocol Label Switching (MPLS) Transport Profile (MPLS-TP)
is the common set of MPLS protocol functions defined to meet the
requirements specified in [RFC5654]. The MPLS-TP Framework
[I-D.ietf-mpls-tp-framework] provides an overall introduction to the
MPLS-TP and defines the general architecture of the Transport
Profile, as well as those aspects specific to point-to-point
transport paths. The purpose of this document is to define the
elements and functions of the MPLS-TP architecture applicable
specifically to supporting point-to-multipoint transport paths.
This document is a product of a joint Internet Engineering Task Force
(IETF) / International Telecommunication Union Telecommunication
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network.
1.1. Scope
This document defines the elements and functions of the MPLS-TP
architecture related to supporting point-to-multipoint transport
paths. The reader is referred to [I-D.ietf-mpls-tp-framework] for
those aspects of the MPLS-TP architecture that are generic, or
concerned specifically with point-to-point transport paths.
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1.2. Terminology
Term Definition
------- ------------------------------------------
LSP Label Switched Path
MPLS-TP MPLS Transport Profile
SDH Synchronous Digital Hierarchy
ATM Asynchronous Transfer Mode
OTN Optical Transport Network
OAM Operations, Administration and Maintenance
G-ACh Generic Associated Channel
GAL G-ACh Label
MEP Maintenance End Point
MIP Maintenance Intermediate Point
APS Automatic Protection Switching
SCC Signaling Communication Channel
MCC Management Communication Channel
EMF Equipment Management Function
FM Fault Management
CM Configuration Management
PM Performance Management
LSR Label Switching Router
MPLS-TE MPLS Traffic Engineering
P2MP Point-to-multipoint
PW Pseudowire
1.2.1. Additional Definitions and Terminology
Detailed definitions and additional terminology may be found in
[I-D.ietf-mpls-tp-framework] and [RFC5654].
1.3. Applicability
The point-to-multipoint connectivity provided by an MPLS-TP network
is based on the point-to-multipoint connectivity provided by MPLS
networks. MPLS TE-LSP support is discussed in [RFC4875] and
[RFC5332], and PW support is being developed based on
[I-D.ietf-pwe3-p2mp-pw-requirements] and
[I-D.ietf-l2vpn-vpms-frmwk-requirements]. MPLS-TP point-to-
multipoint connectivity is analogous to that provided by traditional
transport technologies such as Optical Transport Network (OTN) point-
to-multipoint [ref?] and optical drop-and-continue [ref?], and thus
supports the same class of traditional applications.
2. MPLS Transport Profile Point-to-Multipoint Requirements
The requirements for MPLS-TP are specified in [RFC5654],
[I-D.ietf-mpls-tp-oam-requirements], and [I-D.ietf-mpls-tp-nm-req].
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This section provides a brief summary of point-to-multipoint
transport requirements as set out in those documents; the reader is
referred to the documents themselves for the definitive and complete
list of requirements.
o MPLS-TP must support unidirectional point-to-multipoint (P2MP)
transport paths.
o MPLS-TP must support traffic-engineered point-to-multipoint
transport paths.
o MPLS-TP must be capable of using P2MP server (sub)layer
capabilities as well as P2P server (sub)layer capabilities when
supporting P2MP MPLS-TP transport paths.
o The MPLS-TP control plane must support establishing all the
connectivity patterns defined for the MPLS-TP data plane (i.e.,
unidirectional P2P, associated bidirectional P2P, co-routed
bidirectional P2P, unidirectional P2MP) including configuration of
protection functions and any associated maintenance functions.
o Recovery techniques used for P2P and P2MP should be identical to
simplify implementation and operation.
o Unidirectional 1+1 and 1:n protection for P2MP connectivity must
be supported.
o MPLS-TP recovery in a ring must protect unidirectional P2MP
transport paths.
3. Architecture
The overall architecture of the MPLS Transport Profile is defined in
[I-D.ietf-mpls-tp-framework]. The architecture for point-to-
multipoint MPLS-TP comprises the following additional elements and
functions:
o Unidirectional point-to-multipoint Label Switched Paths (LSPs)
o Unidirectional point-to-multipoint pseudowires (PWs)
o Optional point-to-multipoint LSP and PW control planes
o Survivability, network management, and Operations, Administration
and Maintenance (OAM) functions for point-to-multipoint PWs and
LSPs
The following subsections summarise the encapsulation and forwarding
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of point-to-multipoint traffic within an MPLS-TP network, and the
encapsulation options for delivery of traffic to and from MPLS-TP
Customer Edge devices when the network is providing a packet
transport service.
3.1. MPLS-TP Encapsulation and Forwarding
Packet encapsulation and forwarding for MPLS-TP point-to-multipoint
LSPs is identical to that for MPLS-TE point-to-multipoint LSPs.
MPLS-TE point-to-multipoint LSPs were introduced in [RFC4875] and the
related data-plane behaviour was further clarified in [RFC5332].
MPLS-TP allows for both upstream-assigned and downstream-assigned
labels for use with point-to-multipoint LSPs.
Packet encapsulation and forwarding for point-to-multipoint PWs is
currently being defined by the PWE3 Working Group
[I-D.raggarwa-pwe3-p2mp-pw-encaps].
4. Operations, Administration and Maintenance (OAM)
The overall OAM architecture for MPLS-TP is defined in
[I-D.ietf-mpls-tp-oam-framework].
[Editor's note: This section will contain a summary of point-to-
multipoint OAM as described in the OAM Framework.]
5. Control Plane
The overall control plane architecture for MPLS-TP is defined in
[I-D.abfb-mpls-tp-control-plane-framework].
[Editor's note: This section will contain a summary of the point-to-
multipoint control plane as described in the Control Plane
Framework.]
5.1. Point-to-Multipoint LSP Control Plane
The MPLS-TP control plane for point-to-multipoint LSPs uses
Generalized MPLS (GMPLS) and is based on Resource Reservation
Protocol - Traffic Engineering (RSVP-TE) for point-to-multipoint LSPs
as defined in [RFC4875].
5.2. Point-to-Multipoint PW Control Plane
The MPLS-TP control plane for point-to-multipoint pseudowires is
based on the LDP P2MP signaling extensions for PWs defined in
[I-D.martini-pwe3-p2mp-pw].
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6. Survivability
The overall survivability architecture for MPLS-TP is defined in
[I-D.ietf-mpls-tp-survive-fwk].
[Editor's note: This section will contain a summary of point-to-
multipoint survivability as described in the Survivability
Framework.]
7. Network Management
The network management architecture and requirements for MPLS-TP are
specified in [I-D.ietf-mpls-tp-nm-req]. They derive from the generic
specifications described in ITU-T G.7710/Y.1701 [G.7710] for
transport technologies. They also incorporate the OAM requirements
for MPLS Networks [RFC4377] and MPLS-TP Networks
[I-D.ietf-mpls-tp-oam-requirements] and expand on those requirements
to cover the modifications necessary for fault, configuration,
performance, and security in a transport network.
[Editor's note: Decide what if anything needs to be said about P2MP-
specific network management considerations.]
8. Security Considerations
General security considerations for MPLS-TP are noted in
[I-D.ietf-mpls-tp-framework], and security considerations for point-
to-multipoint PWs and LSPs in the documents that define them. This
document introduces no new security considerations in itself.
9. IANA Considerations
IANA considerations resulting from specific elements of MPLS-TP
functionality are detailed in the documents specifying that
functionality. This document introduces no additional IANA
considerations in itself.
10. References
10.1. Normative References
[I-D.ietf-mpls-tp-framework] Bocci, M., Bryant, S.,
Frost, D., Levrau, L.,
and L. Berger, "A
Framework for MPLS in
Transport Networks", draf
t-ietf-mpls-tp-framework-
12 (work in progress),
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May 2010.
[RFC4875] Aggarwal, R.,
Papadimitriou, D., and S.
Yasukawa, "Extensions to
Resource Reservation
Protocol - Traffic
Engineering (RSVP-TE) for
Point-to-Multipoint TE
Label Switched Paths
(LSPs)", RFC 4875,
May 2007.
[RFC5332] Eckert, T., Rosen, E.,
Aggarwal, R., and Y.
Rekhter, "MPLS Multicast
Encapsulations",
RFC 5332, August 2008.
[RFC5654] Niven-Jenkins, B.,
Brungard, D., Betts, M.,
Sprecher, N., and S.
Ueno, "Requirements of an
MPLS Transport Profile",
RFC 5654, September 2009.
10.2. Informative References
[G.7710] "ITU-T Recommendation
G.7710/Y.1701 (07/07),
"Common equipment
management function
requirements"", 2005.
[I-D.abfb-mpls-tp-control-plane-framework] Andersson, L., Berger,
L., Fang, L., Bitar, N.,
Takacs, A., Vigoureux,
M., and E. Bellagamba,
"MPLS-TP Control Plane
Framework", draft-abfb-
mpls-tp-control-plane-
framework-02 (work in
progress), February 2010.
[I-D.ietf-l2vpn-vpms-frmwk-requirements] Kamite, Y., JOUNAY, F.,
Niven-Jenkins, B.,
Brungard, D., and L. Jin,
"Framework and
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Requirements for Virtual
Private Multicast Service
(VPMS)", draft-ietf-
l2vpn-vpms-frmwk-
requirements-02 (work in
progress), October 2009.
[I-D.ietf-mpls-tp-nm-req] Mansfield, S. and K. Lam,
"MPLS TP Network
Management Requirements",
draft-ietf-mpls-tp-nm-
req-06 (work in
progress), October 2009.
[I-D.ietf-mpls-tp-oam-framework] Allan, D., Busi, I.,
Niven-Jenkins, B.,
Fulignoli, A., Hernandez-
Valencia, E., Levrau, L.,
Mohan, D., Sestito, V.,
Sprecher, N., Helvoort,
H., Vigoureux, M.,
Weingarten, Y., and R.
Winter, "MPLS-TP OAM
Framework", draft-ietf-
mpls-tp-oam-framework-06
(work in progress),
April 2010.
[I-D.ietf-mpls-tp-oam-requirements] Vigoureux, M. and D.
Ward, "Requirements for
OAM in MPLS Transport
Networks", draft-ietf-
mpls-tp-oam-requirements-
06 (work in progress),
March 2010.
[I-D.ietf-mpls-tp-survive-fwk] Sprecher, N. and A.
Farrel, "Multiprotocol
Label Switching Transport
Profile Survivability
Framework", draft-ietf-
mpls-tp-survive-fwk-06
(work in progress),
June 2010.
[I-D.ietf-pwe3-p2mp-pw-requirements] Heron, G., Wang, L.,
Aggarwal, R., Vigoureux,
M., Bocci, M., Jin, L.,
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JOUNAY, F., Niger, P.,
Kamite, Y., DeLord, S.,
and L. Martini,
"Requirements for Point-
to-Multipoint
Pseudowire", draft-ietf-
pwe3-p2mp-pw-
requirements-02 (work in
progress), January 2010.
[I-D.martini-pwe3-p2mp-pw] Martini, L., Boutros, S.,
Sivabalan, S.,
Konstantynowicz, M.,
Vecchio, G., Nadeau, T.,
JOUNAY, F., Niger, P.,
Kamite, Y., Jin, L.,
Vigoureux, M., Ciavaglia,
L., and S. Delord,
"Signaling Root-Initiated
Point-to-Multipoint
Pseudowires using LDP", d
raft-martini-pwe3-p2mp-
pw-01 (work in progress),
October 2009.
[I-D.raggarwa-pwe3-p2mp-pw-encaps] Aggarwal, R. and F.
JOUNAY, "Point-to-
Multipoint Pseudo-Wire
Encapsulation", draft-
raggarwa-pwe3-p2mp-pw-
encaps-01 (work in
progress), March 2010.
[RFC4377] Nadeau, T., Morrow, M.,
Swallow, G., Allan, D.,
and S. Matsushima,
"Operations and
Management (OAM)
Requirements for Multi-
Protocol Label Switched
(MPLS) Networks",
RFC 4377, February 2006.
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Authors' Addresses
Dan Frost (editor)
Cisco Systems
EMail: danfrost@cisco.com
Matthew Bocci (editor)
Alcatel-Lucent
Voyager Place, Shoppenhangers Road
Maidenhead, Berks SL6 2PJ
United Kingdom
EMail: matthew.bocci@alcatel-lucent.com
Lou Berger (editor)
LabN Consulting
Phone: +1-301-468-9228
EMail: lberger@labn.net
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