inter-domain link recovery

michael.dillon at michael.dillon at
Wed Aug 15 09:15:01 UTC 2007

> Thank you for comments. I know there are economic/contractual 
> relationships between two networks, and BGP cannot find a 
> path that the business rules forbid.  But when in these 
> cases, how to recover it? The network operators just wait for 
> physically reparing the link or they may manully configure an 
> alternative path by paying another network for transit 
> service or finding a peering network? 

It sounds like you are asking this question in the context of an
Internet exchange point where you connect to the exchange point, and
then negotiate separate peering agreements with each participant, or a
telecom hotel/data centre. In the exchange point, you could
theoretically have special "INSURANCE" peering agreements where you
don't exchange traffic until there is an emergency, and then you can
quickly turn it on, perhaps using an automated tool. In the data centre,
you could theoretically have a similar sort of agreement that only
requires cross-connect cables to be installed. In fact, you could
already have the cross-connect cables in place, waiting to be plugged in
on your end, or fully plugged in waiting for you to enable the port.

I wonder if anyone on the list has such INSURANCE peering or transit
arrangements in place?

Given the fact that most providers will go to extra efforts to install
new circuits when there is an emergency like the Taiwan quake, perhaps
there isn't as much value to such insurance arrangements as you might

If we ever get to the point where most circuit connections in the core
are via switched wavelengths, then perhaps BGP will be used to find new
paths when others have failed.

--Michael Dillon

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