RSVP-TE Scalability - Remote Node Hello Session

RSVP Traffic Engineering (TE) protocol extensions to support Refresh-interval Independent RSVP (RI-RSVP) defined RFC 8370 for fast reroute (FRR) facility protection allows for greater scalability of label-switched paths (LSPs), faster convergence times, and decreased RSVP signaling message overhead from periodic refreshes. On Juniper devices, RSVP-TE runs in enhanced FRR mode, also known as RI-RSVP mode, by default, which includes protocol extensions to support RI-RSVP for FRR facility bypass originally specified in RFC 4090. Specifically, this feature introduces remote Hello messages between the Point of Local Repair (PLR) node and the Next Hop (NHOP) or Next-Next Hop (NNHOP) node. These remote Hello messages are used to track the reachability of Link Protection Merge Point (LP-MP) or Node Protection Merge Point (NP-MP) after any failure. The address of the remote neighbor is derived in the same manner as the destination address of the Link Protection bypass (LP-bypass) or Node Protection bypass (NP-bypass) LSP is derived.