detecting a "non-versioning-aware client"

Geoffrey M. Clemm (
Sun, 14 Mar 1999 15:49:01 -0500

Date: Sun, 14 Mar 1999 15:49:01 -0500
Message-Id: <9903142049.AA17078@tantalum>
From: "Geoffrey M. Clemm" <>
Subject: detecting a "non-versioning-aware client"

At various times, we have talked about the behavior of a method when
it is applied by a "non-versioning-aware" client.  Hopefully I'm just
missing something obvious, but how exactly do we detect that a request
has been issued by a non-versioning-aware client?

Certainly there will be some protocol versions that are known to be
non-versioning-aware (e.g. HTTP-1.1, etc.), but what about new
protocol extensions?  How can a server determine if a client using
some arbitrary new extension is versioning-aware or not?

One answer is that I've missed something, and we can tell.  We still
may not want to treat versioning-aware and non-versioning-aware
clients differently, but at least we could if we wanted to.

Another answer is that we will treat any client whose versioning
awarenes is unknown as if it were versioning aware.  This could be
rather confusing for a non-versioning-aware client that upgrades
to a new (non-versioning-aware) protocol version, and suddenly
sees very different versioning behavior.

There is an analgous problem with treating unknown protocols as
always non-versioning-aware.

A final answer is that we will not base any behavior on whether the client
is versioning-aware or not.  At the moment, this seems to be the best
answer to me.