IETF RFC 4558 PDF

Use of Node-ID based Resource Reservation Protocol (RSVP) Hello messages is implied in a number of cases, e.g., when data and control planes are separated, when TE links are unnumbered. Furthermore, when link level failure detection is performed by some means other than exchanging RSVP Hello messages, use of a Node-ID based Hello session is optimal for detecting signaling adjacency failure for Resource reSerVation Protocol-Traffic Engineering (RSVP-TE). Nonetheless, this implied behavior is unclear, and this document formalizes use of the Node-ID based RSVP Hello session in some scenarios. The procedure described in this document applies to both Multi-Protocol Label Switching (MPLS) and Generalized MPLS (GMPLS) capable nodes.