1© 2002, Cisco Systems, Inc. All rights reserved.

draft-nadeau-pwe3-vccv-00.txtIETF #56 San Francisco, CA USA

Thomas D. Nadeautnadeau@cisco.com

Monique MorrowMmorrow@cisco.com

George SwallowSwallow@cisco.com

ftp://ftp-eng.cisco.com/tnadeau/oam/draft-nadeau-pwe3-vccv-00.txt

2© 2002, Cisco Systems, Inc. All rights reserved.

Based on MPLS OAM and Customer Requirements

• Driven by a need to provide a common means of testing PWEs using an in-band diagnostic mechanism.

• ftp://ftp-eng.cisco.com/tnadeau/oam/draft-nadeau-mpls-oam-requirements-00.txt

Soon to be draft-ietf-mpls-oam-requirements-00.txt

3© 2002, Cisco Systems, Inc. All rights reserved.

Motivation

• One transport tunnel can serve many pseudo-wires and we can verify that path with existing tools…

(e.g.: MPLS ping is sufficient to monitor the PSN tunnel for PE-PE connectivity, but not VCs inside of tunnel.)

• But…we cannot verify the PWs themselves using existing tools.

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VCCV Key Points

• Provides extensible foundation for PW OAM CV/trace functions.

• Will work with supported transport tunnels MPLS and L2TPv3 (soon)

• Different CV types to support different PWs when appropriate

LSP Ping, IP Ping, VPLS (future)

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VCCV Key Points (2)

• Modify PWE Encapsulation HeaderSome reserved bit for OAM indication.

Current bit in draft is already assigned; need to choose a new one.

Capability Signaled During VC setup as a bit mask of allowable VCCV types.Carry multiple TLVs as payload to allow for different types of OAM operations.

Support MPLS and L2TPv3 transportsSupport p2p and VPLS applications

Straight-forward to implement.• Reference

ftp://ftp-eng.cisco.com/tnadeau/oam/draft-nadeau-pwe3-vccv-00.txt

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Example of OperationCV/Trace Using VCCV and LSP Ping

Attachment VC

VCCV PacketIs lostAttachment VC

NMS/mgr Triggers VCCV

NMS/mgr Triggers LSP ping trace when failure detected

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Open Issues

• As currently defined VCCV parameter does NOT need to be identical in both directions of a circuit, so no cases where the signaling MUST be rejected

In order to support certain functions in future one might want to reject a setup (e.g. the far end did not indicate Ping, but I'm configured to do CV with Ping).

• The description of signaling is incorrect. 

Needs to be single sided (downstream unsolicited).

• Need to add VCCV type for L2TPv3• Current bit in draft is already assigned; need to choose a new

one

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Next Steps

• Refinements

Support L2TPv3 transport.

Editorial enhancements.

• Accept as a PWE3 WG document.

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Thank You