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LDP extensions for Explicit Pseudowire to transport LSP mapping. draft-cao-pwe3-mpls-tp-pw-over-bidir-lsp-01.txt Mach Chen (mach@huawei.com) Wei Cao ( caowayne@huawei.com ) Attila Takacs (Attila.Takacs@ericsson.com). IETF 79 th PWE3 WG Beijing.
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LDP extensions for Explicit Pseudowire to transport LSP mapping draft-cao-pwe3-mpls-tp-pw-over-bidir-lsp-01.txt Mach Chen (mach@huawei.com) Wei Cao (caowayne@huawei.com) Attila Takacs (Attila.Takacs@ericsson.com) IETF 79th PWE3 WG Beijing
Problem statement • Currently, • A PW uses two unidirectional LDP/RSVP-TE LSPs as PSN Tunnel, • Each PE of the PW selects and binds to PSN Tunnel independently, there is no control plane support • Transport services (e.g., MPLS-TP)normally require co-routed bidirectional paths, but • Current mechanisms can not guarantee this, especially when: • there are multiple LSPs with different paths and/or QoS levels between the two Pes. • Manual configuration is an alternative method, but • prone to configuration errors • difficult to maintain a large number of PWs • Explicit control of PW to PSN tunnel binding is required • Stated in Section 5.3.2 of MPLS-TP control plane framework IETF 79th PWE3 WG Beijing
AC AC An example of improper mapping • A PW bound to two different LSPs • Forward direction of PW1 bound to bidirectional LSP 1, • Reverse direction of PW1 bound to unidirectional LSP 2. PE1 P1 P2 LSP 1 PE2 PW1 PW1 LSP 2 IETF 79th PWE3 WG Beijing
AC PW Proposed solution • Extension to PW signaling protocol • Make sure both ends select and bind to the same bidirectional LSP or two unidirectional LSPs with congruent paths PE1 P1 P2 PE2 PW1 PW1 AC PW2 PW2 Unidirectional LSP Bidirectional LSP
Proposed solution (cont.) • Two new TLVs: PW to LSP Binding TLV (IPv4/v6) • Optional TLV, no compatibility issue, • Carried in LDP messages for communicating tunnel LSP selection when setup PW, • Identify the selected LSP by the combination of: • Source/Destination Global ID • Source/Destination Node ID • Source/Destination Tunnel ID • Source/Destination LSP ID IETF 79th PWE3 WG Beijing
Next steps • Any comments are appreciated! • WG document? IETF 79th PWE3 WG Beijing