Packet over SONET failback

[Jason Lixfeld <jason () lixfeld ca>]

PoS failure detection happens in under 50ms, but what about the failback?  Same deal?  I ask because I've got two 
routers connected to opposite ends of a spare PoS link that I've been playing with and I'm noticing that the failback 
on the far side seems to be about 15 seconds (assuming the near side failover was initiated with an interface shutdown 
command and thusly no shut'd to re-enable the link).  Just wanted to know if a higher failback time is a relatively 
normal occurrence and maybe I'm seeing some sort of built-in hold down feature working away?