General FRR End to End

1.

request for protection. Each router along the path of the LSP records the

route and label for the HE router.

If protection is desired in an LSP, the RSVP-TE signals the LSP with a

2.

by sending an RESV message back. The FRR is established only after

the protected LSP-Path comes

each router does not start the signaling or protection tunnels. The RESV

message from P6 for the initial LSP path establishment does not report

whether the local protection is available yet.

After the PATH message reaches the Tail router P6, P6 establishes the LSPPathup operationally. Therefore, at this moment,

3.

Then, the CSPF in each router starts calculating the detour LSP or

bypass tunnel based on the network topology stored in the TED, and the

original path of the LSP recorded in the RRO object by each hop.

After the initial RESV reaches the P1 router, the protected LSP is established.

4.

the CSPF calculation. If the detour LSP or bypass tunnel is established, the

router then announces the protection availability to the HE router.

Each potential PLR router signals the detour LSP or bypass tunnel based on

5.

protection are available from which router.

When a failure happens, the PLR immediately uses the pre-signaled protection

to reroute the traffi c around the failure and notifi es the HE router via

the At this point, the HE router of the protected LSP has a view of what types ofPathErr message and the RESV message.