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This draft extends the PW stitching procedures to include Lock Instruct and Loopback OAM functions for MPLS-TP networks. It also covers PW OAM messages for static PWs and defines the PW static FEC.
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PW Stitching Procedures in MPLS-TP Networksdraft-boutros-pwe3-ms-pw-tp-00 Sami Boutros Siva Sivabalan Luca Martini
Background • This draft extends the PW stitching procedures defined in “draft-ietf-pwe3-segmented-pw-15.txt” to include:- • Lock Instruct (LI) and Loopback (LB) OAM functions for MPLS-TP networks specified in“draft-boutros-mpls-tp-li-lb-00.txt”. • PW OAM messages for static PWs specified in “draft-ietf-pwe3-static-pw-status-00.txt”. • PW static FEC defined in “draft-nitinb-mpls-tp-on-demand-cv-00.txt”.
LI on MPLS-TP LSP (1) PW 1 3 2 MPLS-TP LSP T-PE1 S-PE PW status (0x00000018) T-PE2 LI Request LI Reply • PW status can be sent via LDP or PW OAM depending on whether the PW is dynamic or static respectively • If PW status not supported, Label Withdraw method is used
LI on MPLS-TP LSP (2) PW 2 1 3 MPLS-TP LSP PW status (0x00000018) T-PE1 S-PE T-PE2 LI Request LI Reply • Same as the previous case except that LI request originates at S-PE • If LI reply is negative, S-PE sends PW status 0x00000000 to T-PE2 to re-activate PW
LI on PW PW 1 4 2 3 MPLS-TP LSP LI Request LI Request T-PE1 S-PE T-PE2 LI Reply LI Reply • LI request originating from T-PE1 is intended for S-PE. Upon receiving LI request, S-PE relays it to T-PE2. • If S-PE cannot relay LI request to T-PE2, it can use either PW status 0x00000018 or label withdraw method to bring down PW between itself and T-PE2
LB on MPLS-TP LSP PW 1 3 2 MPLS-TP LSP T-PE1 S-PE PW status (0x00000018) T-PE2 LB Request LB Reply • Once MPLS-TP LSP between T-PE1 and S-PE is setup in LB mode, all PW traffic from T-PE1 to S-PE will be looped back to T-PE1
LB on PW PW 1 3 2 MPLS-TP LSP LB Request T-PE1 S-PE PW status (0x00000018) T-PE2 LB Reply • Once PW between T-PE1 and S-PE is setup in LB mode, all PW traffic from T-PE1 to S-PE will be looped back to T-PE1
Future Work • Align with MPLS-TP drafts Guidance:- • Rename to draft-boutros-pwe3-mpls-tp-ms-pw-00.txt • Include the paragraphs in http://wiki.tools.ietf.org/misc/mpls-tp/wiki/Boilerplate%20for%20MPLS-TP%20Internet-Drafts • Add new sub-TLV type to represent static PW FEC in S-PE TLV