How about DNS? Admittedly EDN0 was grafted on - but only to deal
with changes and expansions to DNS. DNS did fine without it for many
many years.

With respect to negotiations in DNS - there are actually two
protocols involved - the transmission protocol and the data
protocol. It's somewhat easier to add negotiation to the
transmission protocol (and that's what EDNS0 did in part) because
it's between just a client and a server during a specific
conversation. Adding negotiation to the data protocol is a bit
harder (see for example grafting on the notion of non-existence and
the various indications that have to go into the data to signal to a
resolver/validator meanings). Its also the case that the publisher of
the data doesn't have a clue as to the capabilities of its consumers
and they will vary wildly.

So without a massive change to the data model (which may in turn lead
to a massive change in the name space with all the political issues
thereof - ??), I'm mostly with Ed here. If you just want to re-write
the query language and leave the data structures mostly intact - then
lets just get the query language correct at the start. We've got 20
years of experience with DNS that should allow us to write a tight
protocol for the next 20 years.


At 11:26 AM 12/18/2006, Paul Vixie wrote:
> > I think that what is lost often is what makes the DNS a good protocol. ...

>ask five people this question, get seven distinct nonoverlapping answers.
> > ... But, please, abandon the hope of negotiating service parameters - ...

>i can't think of a successful protocol that lacks an "options" escape-hatch?
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