LSP-Ping and BFD encapsulation over ACH draft-nitinb-mpls-tp-lsp-ping-bfd-procedures Nitin BahadurRahul Aggarwal Dave WardTom Nadeau Nurit SprecherYaacov Weingarten MPLS WG IETF 77, Anaheim 1MPLS WG, IETF 77

Motivation Re-use existing mpls oam techniques for MPLS-TP LSPs IP forwarding might be unavailable or not-preferred => Need a way to adapt existing techniques (LSP-Ping & BFD) MPLS WG, IETF 772

Solution Use ACH channel for OAM on MPLS-TP LSPs – Applicable to regular MPLS LSPs as well New ACH code-point for carrying LSP-Ping data ACH code-point for BFD already exists. MPLS WG, IETF | MPLS Label stack | | | | GAL | | |Version| Reserved | LSP-Ping Channel Type | | ACH TLV Header | | ACH TLVs | | | | LSP-Ping payload | | | | MPLS Label stack | | | | GAL | | |Version| Reserved | BFD Channel Type | | ACH TLV Header | | ACH TLVs | | | | BFD payload | | |

ACH TLVs MPLS WG, IETF 774 Source address TLV MAY be used to identify src of pkt MEP &MIP identifier TLVs MAY be included

BFD Usage BFD should be run pro-actively for Connectivity Check BFD should be run between MEPs BFD failure can be used to trigger protection switching MPLS WG, IETF 775

BFD Procedures BFD discriminator must be signaled (LSP-Ping, etc.) or statically configured Co-routed bi-directional LSPs – BFD packets MUST be sent on LSP return path ONLY. – Only LSP ingress SHOULD signal the BFD session. – Only 1 BFD session needed per LSP Associated bi-directional LSPs – BFD packets MUST be sent on the associated LSPs only – Both LSP end-points MAY signal separate BFD sessions. – Recommendation: Use only 1 BFD session MPLS WG, IETF 776

Next Steps Draft already accepted as WG doc Need to clarify text regarding BFD sessions MPLS WG, IETF 777