Technical Documentation

Option: Tearing Down GMPLS LSPs Gracefully

You can tear down a nonpacket GMPLS LSP in a two-step process that gracefully withdraws the RSVP session used by the LSP. For all neighbors that support graceful teardown, a request for the teardown is sent by the routing platform to the destination endpoint for the LSP and all RSVP neighbors in the path. The request is included within the ADMIN_STATUS field of the RSVP packet. When neighbors receive the request, they prepare for the RSVP session to be withdrawn. A second message is sent by the routing platform to complete the teardown of the RSVP session. If a neighbor does not support graceful teardown, the request is handled as a standard session teardown rather than a graceful one.

To perform a graceful teardown of a GMPLS LSP RSVP session, issue the clear rsvp session gracefully command. Optionally, you can specify the source and destination address of the RSVP session, the LSP identifier of the RSVP sender, and the tunnel identifier of the RSVP session. To use these qualifiers, include the connection-source, connection-destination, lsp-id, and tunnel-id options when you issue the clear rsvp session gracefully command.

You can also configure the amount of time that the routing platform waits for neighbors to receive the graceful teardown request before initiating the actual teardown. To configure the timeout, include the graceful-deletion-timeout statement at the [edit protocols rsvp] hierarchy level. The default graceful deletion timeout value is 30 seconds, with a minimum value of 1 second and a maximum value of 300 seconds. To view the current value configured for graceful deletion timeout, issue the show rsvp version operational command.

Published: 2010-04-15