From: Venkataramanaiah.R (vramanaiah@gmail.com)
Date: Wed May 02 2007 - 06:18:42 ART
Hi,
We are working on a subsecond Routing convergence project and we have the
following dilemma...
We have WAN links from 2 service providers/technology.. Two links from DWDM
and two MPLS links at each site..
Basically, A single link failure out of these 4 links isnt a issue.. Network
converges really fast.. However,we have trouble when the entire DWDM is
blacked out; ie., 2 DWDM links go down at the same time...
Basically we have the following timers
LSA - Timers
Initial Start - 0 ms
Hold time - 5 secs
Max wait - 20 secs
SPF throttle timers
Inital Start - 50 ms
Hold time - 10 secs
Max wait - 20 secs..
basically, with these timers, the change is detect instantly and
communicated by the routers; however detecting this multiple order failure
isnt recovering for 5 to 10 secs; obviously due to these timers.After the
first change detectection, there is a minimum hold time 5 to 10 secs, which
is causing this delay..
We dont want to reduce these Hold time to subsecond, to ensure stability..
Is there a way out to overcome this situation..?
Regards
-Venkat
This archive was generated by hypermail 2.1.4 : Fri Jun 01 2007 - 06:55:19 ART