Re: Transport level multihoming

[Brian E Carpenter <brian@hursley.ibm.com>]

Ben Black wrote:
> 
> >
> > This working group has pretty much painted themselves into a corner by
> > concluding that application level changes for multihoming support are not
> > acceptable.
> >
> 
> I am part of this working group and I have definitely not concluded this.
> I have concluded the exact opposite, and I believe rather strongly that
> the reason this situation exists is layer violation (why does the
> application
> need to know the network and transport addresses?).

There is certainly a lot of evidence building up that the multi6 solution 
will require work at the transport layer; once we have agreed requirements 
we can be more precise about that conclusion. 

On the other hand we know that major restructuring of applications isn't going
to happen - that's the real world. So if we have to do work in the transport
layer, the transport layer is going to have to hide most of it below some
sort of socket API. I can't see any reason in principle why that API
would have to expose a bunch of addresses, even if it turns out that
multi6 requires more than one. A "primary" address per host would be enough
to expose to the middleware.

   Brian