The requirements of MPLS-TP in RFC 5654 include a requirement(R63)
that requires MPLS-TP MUST be possible to provide protection for
MPLS-TP data plane without any IP forwarding capability and control
plane.If applying 1:1 protection mechanism for the p2mp traffic in
rfc6718 , it must have a return path to coordinate switch state to
select the same path to receive and send traffic packet.For the above
problem,this document describes a kind of protection solution to
recovery and protect the p2mp traffic under the failure condition.
This document is a product of a joint Internet Task Force(IETF) /
International Telecommunications Union Telecommunications
Standardization Sector (ITU-T) effort to include an MPLS Transport
Profile within the IETF MPLS and PWE3 architectures to support the
capabilities and functionalities of a packet transport network as
defined by the ITU-T.