GMPLS Operation

The basic functionality of GMPLS requires close interaction between RSVP and LMP. It works in the following sequence:

LMP notifies RSVP of the new entities:
- Traffic engineering link (forwarding adjacency)
- Resources available for the traffic engineering link
- Control peer
GMPLS extracts the LSP attributes from the configuration and requests RSVP to signal one or more specific paths, which are specified by the traffic engineering link addresses.
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 finds a resource matching the attributes, label allocation succeeds. RSVP sends a PathMsg hop by hop until it reaches the target router.
When the target router receives the PathMsg, RSVP again requests that LMP allocate a resource based on the signaled parameters. If label allocation succeeds, the router sends back a ResvMsg.
If the signaling is successful, a bidirectional optical path is provisioned.