[EMAIL PROTECTED] wrote:
> I was talking about subsequent requests in the dialog once both
> endpoints have established the Route set.
Once both end points have established a Route set, I wouldn't
think there would be a spiral (unless a proxy appears intentionally
in the Route set more than once, for whatever reason).
> You are right that during the initial request, the Via branch
> aids in loop detection. But if you do not insert unique R-R's
> during each iteration of the spiral, subsequent requests in the
> dialog that are spiralling will seem like a loop at your proxy.
> This is what i was referring to.
Not quite. Spiraling and looping are different things -- a spiral is
a legal loop. The whole point of inserting a unique identifier in a
R-R request going downstream is to retrieve it when the response
arrives at the same proxy for the purpose of changing the URI. Of
course, the request may have spiraled through the proxy so there
may be multiple R-R headers inserted by the same proxy in the
response. So how does it know which header to modify -- it looks
for the unique identifier it inserted earlier. All these machinations
have nothing to do with loop detection.
The machinations described in -05bis to maintain two different URIs
in the R-R going downstream and upstream was mainly because we were
using the R-R URI (and thus Route URI) both to identify the endpoint
and the next hop proxy. With the newer loose routing technique
described in -09bis, this is no longer needed as much.
Regards,
- vijay
--
Vijay K. Gurbani vkg@{lucent.com,research.bell-labs.com,acm.org}
Wireless Networks Group/Internet Software and eServices
Lucent Technologies/Bell Labs Innovations, 2000 Lucent Lane, Rm 6G-440
Naperville, Illinois 60566 Voice: +1 630 224 0216
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