Re: A tunneling proposal

[Ramakrishna Gummadi <ramki@cs.berkeley.edu>]

> one of the main problems with the tunnel approach (and I'm not saying there is
> indeed a currently practical or better way) is that it requires a degree of
> cooperation between ISP-A and ISP-B, which also means that the "decision" is
> made independently of the end-network. It moves the redundancy from a "local"
> solution up the AS hierarchy, which is what the *LA design was about. One of
> the desireable features of current IPv4 multihoming is the ability to solve
> for "local" connectivity loss (local-loop/router failure) via "local"
> redundancy.


I am not certain this is the case. The tunnel will be initiated only at
the request of the multihomed site that detects problems with the other
ISP, say ISPB. In any case, remember that one end of the tunnel has to be
terminated
at the site's border router. The other end should be terminated within
ISPB, but where exactly this is done can be made a performance-optimizing
criterion from the perspective of ISPA who has to carry the tunneled
traffic. In any case, since it involves only the site's ISPs, I think this
setting up a tunnel may indeed by feasibly, although it may not be optimal
in every scenario.

-ramki