[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Congestion issue [Re: shim6-proto-07 review]



Iljitsch van Beijnum wrote:
On 14-dec-2006, at 14:31, Brian E Carpenter wrote:

I am a little puzzled by this concern. In a conventional multihoming situation where BGP4 routing changes, we get an unplanned and unexpected path change, and TCP deals with it as best it can. As far as TCP is concerned, shim6 is the same - an unexpected path change. On the "first do no harm" principle,
shim6 can do exactly the same as BGP4 multihoming - nothing.


The scale of shim multihoming is potentially quite different than that of BGP multihoming that we have today. Presumably, in a current setup, the amount of backup bandwidth is such that any congestion after a path change is survivable. On the other hand, the shim allows many more people to multihome, including single hosts that may have both very fast and very slow links. For instance, my laptop has a 1 Gbps interface and a 9600 bps interface, five orders of magnitude. With BGP, I've never even seen two.

Understood, but this won't break TCP will it? So while this
is a longer term concern, I don't see why we need to deal with
it now. We could usefully document that we are not dealing with it.

   Brian