3.6 Local Repair

When a route changes, the next Path or Resv refresh message will establish path or reservation state (respectively) along the new route. To provide fast adaptation to routing changes without the overhead of short refresh periods, the local routing protocol module can notify the RSVP process of route changes for particular destinations. The RSVP process should use this information to trigger a quick refresh of state for these destinations, using the new route.

The specific rules are as follows:

• When routing detects a change of the set of outgoing interfaces for destination G, RSVP should update the path state, wait for a short period W, and then send Path refreshes for all sessions G/* (i.e., for any session with destination G, regardless of destination port).

  The short wait period before sending Path refreshes is to allow the routing protocol to settle, and the value for W should be chosen accordingly. Currently W = 2 sec is suggested; however, this value should be configurable per interface.

• When a Path message arrives with a Previous Hop address that differs from the one stored in the path state, RSVP should send immediate Resv refreshes to that PHOP.