Subject: Re: Evaluation of Gateway Location proposals

From: Matt Squire <[email-masked]>
Date: Wed, 12 May 1999 14:07:00 -0400

>I think in call routing, when the connection between LS A and LS B is
>disconnected (due to any reason), LS A should immediately delete any
>call routes it has previously learned from LS B. As a result, when the
>connection between LS A and LS B is restored, both LSs will have to
>exchange their entire call routing databases. 
>

If the next hop on a call route received from B is B, then the route should
be deleted when B goes away.  But in when the next hop is not B, we might
consider having LS A keep the route around for "a little while."  Haven't
really given this enough thought yet, but it might help with transient
failures (ie B is just being rebooted and will be up again in two minutes).  

Just a thought...

- Matt

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From: "Hussein F. Salama" <[email-masked]>
Date: Fri, 14 May 1999 13:06:13 -0700

> failures (ie B is just being rebooted and will be up again in two minutes).

What if B advertises the addresses of the gateways in its domain as the
next hops, not its own address. When B goes away, there will be no way
to advertise to other domains updated information about these gateways
and the prefixes they can reach (assuming B is the only LS in that
domain).

This is an issue where we can present good examples for both approaches.
I think deleting all call routes learned from B immediately when B is
disconnected is the safer approach. We will probably re-learn the routes
which are still valied through alternate paths.

Hussein

-- 
Hussein F. Salama
Cisco Systems
Mail Stop SJC6/3, 170 W. Tasman Drive, San Jose, CA 95134
Voice: +1 (408) 527-7147, Fax: +1 (408) 527-1714

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