GMPLS Operation

GMPLS requires close interaction between LMP, RSVP, and OSPF. The following sequence of events describes how GMPLS works:

1. LMP notifies RSVP and OSPF of the control peer, the control adjacency, and resources for the traffic engineering link.
2. GMPLS extracts the LSP attributes from the configuration and requests that RSVP signal one or more specific paths, specified by the traffic engineering link addresses.
3. RSVP determines the local traffic engineering link, corresponding control adjacency and active control channel, and transmission parameters (such as IP destination). It requests that LMP allocate a resource from the traffic engineering link with the specified attributes. If LMP successfully finds a resource matching the attributes, label allocation succeeds. RSVP sends a PathMsg hop by hop until it reaches the target router.
4. The target router, on receiving the RSVP PathMsg, requests that LMP allocate a resource based on the signaled parameters. If label allocation succeeds, it sends back a ResvMsg.
5. If the signaling is successful, an optical path is provisioned.