Subject: [Sipping] "GRUU Issue" thread

From: Rohan Mahy <[email-masked]>
Date: Fri, 28 Jan 2005 13:56:13 -0800

Hi Folks,

<chair>
Those who are participating in the "GRUU Issue" thread, please try to 
keep the following in mind:

1) We started the GRUU work with a set of requirements which are still 
in the GRUU document (see Section 11). We had pretty solid consensus on 
the requirements for several months, so if you think something is wrong 
with the mechanism, please look carefully at the requirements so we can 
figure out if a) the proposed GRUU mechanism does not address an 
existing requirement, b) the GRUU requirements are missing or 
incorrect,  or c) you have additional requirements which is not really 
specific to GRUU but doesn't seem to work the way the GRUU mechanism is 
specified now.

2) If you think there is problem because of 1b or 1c, it is possible 
that your problem/requirements might be out of scope.

If you post on this topic you should try to articulate which 
requirements aren't getting addressed, and if they are in the draft now 
or not. I do not want to see us discuss this mechanism and endlessly 
disagree on mechanism because of an underlying requirements mismatch.

Thanks for your cooperation.
</chair>

<individual>
Personally, I think the core of the problem that Paul K brought up at 
the beginning of this thread is orthogonal to GRUU, and has more to do 
with Identity.  I believe this problem can be best solved with one 
simple rule: If you are sending a new dialog-initiating request to a 
GRUU or Contact URI and you know an appropriate corresponding AOR, you 
should place that AOR in the To header.
</individual>

thanks,
-rohan

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---

From: Paul Kyzivat <[email-masked]>
Date: Fri, 28 Jan 2005 19:21:21 -0500

> that your problem/requirements might be out of scope.

Thanks Rohan.

I believe the entire thread is postulated on a *potential* *new* 
requirement. Here is a swag at that requirement:

REQ 11: When a GRUU is bound to a UA instance that is also bound to an 
AOR, it SHOULD be possible for a holder of the GRUU to recover the 
corresponding AOR. (Even if the GRUU binding has been severed, and 
possibly even if the AOR itself has been undefined.)

You are right that it is important to nail down whether this is agreed 
to be a valid new requirement, and whether it can/should be added at 
this time. The basic justification for this is that there was resistance 
to using GRUUs (especially in presence tuples) because they lacked this 
property.

> should place that AOR in the To header.

I agree this may be a solution to the problem.

I am just interested in removing this as an argument for using AORs in 
presence tuples, in an ambiguous way, because of resistance to using GRUUs.

	Paul