nov 2009 draft-ietf-mpls-tp-framework-06.txt a framework for mpls in transport networks...

Nov 2009 draft-ietf-mpls-tp-framework-06.txt

A framework for MPLS in Transport networksdraft-ietf-mpls-tp-framework-06.txt

Stewart Bryant (Cisco), Matthew Bocci (Alcatel-Lucent) (Eds.)Lieven Levrau (Alcatel-Lucent)

Dan Frost (Cisco)


Objectives of the MPLS-TP Framework

• Provide a high level overview of the functional components of MPLS that can be used for a packet transport service, as per RFC5654

• Presents an architectural framework to illustrate how those components fit together

• Implementations can choose which functions to use as applicable to their role in a network

• A specific implementation does not necessarily need all functions


Changes Since IETF 75

• Major rewrite to align with ongoing debate on MPLS-TP architecture and improve readability

• Expanded terminology section:– MPLS Transport Profile and its relationship to MPLS

– MPLS-TP LSP, PE, P and CE

• Removed P2MP content– This will be covered in a separate draft


Changes since IETF 75

• Clarified applicability / scope of MPLS-TP• Architecture now split into Adaptation and Forwarding

Functions • Clients:

– Includes Pseudowires and Network Layer Protocols (IP and MPLS)

• Alignment of sections covering OAM with OAM framework draft.

• Currently under review by ITU-T


Scope of MPLS-TP

Existing MPLS RFCsprior to RFC5654

•ECMP•LDP / non-TE LSPs•IP forwarding

MPLS-TPSubset to meet transport network operational requirements•MPLS/PWE3 architecture•MPLS forwarding•GMPLS/PWE3 control

MPLS

Additionalfunctionality based on Transport Requirements


MPLS-TP Clients

• Extensive discussion on the list about which clients are applicable, and how they fit into the MPLS-TP architecture

• Pseudowires:– PW used for services defined by L2VPN– SS-PW and MS-PW supported– MS-PW only needed if required as per RFC5254

• Network Layer Clients:– IP and MPLS– Detailed architecture described– Use service label to demux network layer client– Optional Encapsulation label indicates protocol


MPLS-TP clients

• Service implemented using LSP– anything that MPLS can support: LSP, IP, PW

• Service implemented using PW– anything that PW can support

• Data-plane behaviour matches best current practice that MPLS and PW data plane supports today


MPLS-TP - Client relationship

LSP labelS=1

IPPW labelS=1

LSP labelS=0

PW Payload

LSP label*S=1

LSP labelS=0

LSPPayload

MPLS-TP layer

Client layer

Labelledservice

PW-basedservice

- PW-based service includes packet PW if desired- Label stacks are those inside MPLS-TP network- Label stacks shown are the smallest no. labels possible. These could include more labels.*Could be NULL

IP service


Next Steps

• Address ITU-T feedback and further comments from IETF participants

• Align OAM, control plane and survivability sections with their respective framework drafts, and where possible simplify content

• ….then WG last call?

nov 2009 draft-ietf-mpls-tp-framework-06.txt a framework for mpls in transport networks...

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