Brian E Carpenter <[EMAIL PROTECTED]> writes:
> > We can already classify ESP traffic. The SPI for a particular host to
> > host connection is externally visible likely unique for a given
> > flow in most applications. (The VPN case is a bit different but the
> > VPN case is, we hope, not the bulk of traffic in the future.)
> 
> Sorry, the SPI is no good for diffserv classification
> because it has no semantics.

Neither does the flow label. Both are just a number that can be used
to distinguish a bunch of traffic flowing between two hosts from other
traffic flowing between two hosts. Neither has any semantics beyond
that.

> > We can also already label the individual packets according to
> > traffic class.
> 
> No, because it's mutable. We need sonmeting that *isn't* mutable
> and *does* have semantics for classification.

I am perhaps a bit thick, Brian, but all the flow label seems to
indicate is that a host believes that a bunch of traffic going to
another host is distinct from a bunch of other traffic by some
mysterious criterion it has itself selected. Since we've imposed more
or less no other implications in the draft (am I mistaken here?) it
doesn't have particularly any semantics for classification there
either.

> > > or simply a matter of heat dissipation and the marginal cost of
> > > a chip set.
> > 
> > Well, if it truly makes no difference, why are we advocating the change?
> 
> I didn't say it makes no difference. I said that the difference is more
> likely to be in cost and waste heat than in speed.

Given that the manufacturers who are doing this are already building
the transistors in to walk the header chain...

--
Perry E. Metzger                [EMAIL PROTECTED]
--
NetBSD Development, Support & CDs. http://www.wasabisystems.com/
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