Stewart Bryant stbryant@cisco.com TMPLS Background Stewart Bryant stbryant@cisco.com

T-MPLS T-MPLS was liaised to IETF after it was consented by the ITU. Product of ITU-T SG15 Q12 - G.8110(.1), G.8112, G.8121, G.8131 T-MPLS is essentially an Ethernet PW, running over MPLS PSN, running over Ethernet OAM is G.8114/Y.1373 a derivative of Y.1711, currently in AAP (restricted last call) Existing definition is statically - centrally - configured however ITU looking at developing a control plane Normative text is a complete re-definition of the protocol using specialist ITU language and formal notation.

TMPLS & MPLS Disjoint? ITU SG15 experts claim that MPLS and T-MPLS will always be configured to be in disjoint layers in the network and that this is sufficient. Goal is to be able to transport T-MPLS on existing equipment via the use of MPLS codepoint. Disjoint layers claimed as TMPLS is "below MPLS" Claimed no need for different codepoint as no intentions for interoperability (However ITU interoperability contributions have been presented in SG15 )

IETF Concerns Liaison statements have been exchanged and various IAB/IESG/WG chairs have attended a number of ITU SG15 meetings in person expressing concerns about T-MPLS. IETF is concerned that T-MPLS, or a development of T-MPLS will break MPLS or an IETF development of MPLS. Issue is shared code point for different specification of the functionality and attributes. Excellent opportunity for collision. Experience tells us that initial limited functionality never remains limited. Massive interoperability issues could ensue Work plan includes incorporating new PW types that duplicate existing IETF PWE Further discussion will take place in PWE3 this afternoon.