Clarifying Procedures for Establishing BFD Sessions for MPLS Label Switched Paths (LSPs)

Seamless Bidirectional Forwarding Detection (S-BFD) Use Cases

“…Section 4 of [RFC5884] also describes the possibility of running multiple BFD sessions per alternative of LSPs. [RFC7726] further clarifies the procedures, for both ingress and egress nodes, regarding how to bootstrap, maintain, and remove multiple BFD sessions for the same <MPLS LSP, FEC> tuple ("FEC" means Forwarding Equivalence Class). However, this mechanism still requires the use of MPLS LSP Ping for bootstrapping, round trips for initialization, and keeping state at the receiver.…”