Subject: [SIP] wg last call on reliable provisional responses

From: Jonathan Rosenberg <[email-masked]>
Date: Sun, 28 May 2000 04:17:24 -0400

Folks,

I've just submitted an updated version of the I-D on "Reliability of
Provisional Responses in SIP". Until it appears in the archives, you can
find a copy at:

http://www.cs.columbia.edu/~jdrosen/papers/draft-ietf-sip-100rel-01.txt

The changes since the last version are:

1. CANCEL disallowed for PRACK
2. Require allowed in requests for this extension
3. option tag changed from org.ietf.sip.100rel to 100rel
4. Proxy-Require disallowed
5. discussion of sending final responses to original request before all
reliable provisional responses have been received (its allowed)
6. clarifications

Once this draft appears in the archives, a two week working group last
call will begin. At the end of that last call, if no comments are heard,
the document will be sent to IESG for consideration as proposed
standard.

Thanks,
Jonathan R.
-- 
Jonathan D. Rosenberg                       72 Eagle Rock Ave.
Chief Scientist                             First Floor
dynamicsoft                                 East Hanover, NJ 07936
[email-masked]                     FAX:   (732) 741-4778
http://www.cs.columbia.edu/~jdrosen         PHONE: (732) 741-7244
http://www.dynamicsoft.com

_______________________________________________
SIP mailing list
[email-masked]
http://lists.bell-labs.com/mailman/listinfo/sip

---

From: "Jo Hornsby" <[email-masked]>
Date: Tue, 30 May 2000 10:12:02 +0100

Hi,

(SIP List: Apologies for the use of "Gentlemen" in my last post;
 very poor indeed.)

> Provisional Responses in SIP". Until it appears in the archives, you
> can find a copy at:
[...]

Well it's certainly easier for a proxy than the original draft (00).
Which makes me happy. &:)

One thing I'm a little confused about: Section 5.2 (UAS Behavior)
contains the following text:
   "Note that a UAS can send reliable provisional responses
    for any request, including a PRACK request. It is anticipated
    that reliable provisional responses will be most useful for
    INVITE requests."
Is allowing a PRACK to be responded to with reliable provisional
responses potentially a big old nightmare?  Or am I just being a
little bit dull, really?  Also, shouldn't it be stated that
reliable provisional responses can't be used with ACK?

Cheers,

 - Jo.

---

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 30 May 2000 18:25:21 -0400

Jo Hornsby wrote:
> responses potentially a big old nightmare? 

Only if you implement it wrong ;)

The whole idea is that PRACK is a request, like any other. If you don't
treat it differently than any other request, in terms of its ability to
be responded to, you have no problem. 

However, if people want to nix the ability to send reliable provisional
responses to PRACK itself, I am willing to discuss. I doubt its useful.

 Or am I just being a
> reliable provisional responses can't be used with ACK?

ACK can never have responses; this draft doesn't change that. I don't
think its confusing, but I'll add some verbiage to that effect.

-Jonathan R.

---

From: James Undery <[email-masked]>
Date: Wed, 31 May 2000 08:52:51 +0100

> Only if you implement it wrong ;)

I think what is being hinted at albeit subtlety is, is the transaction ever
going to end? (The Halting Problem.) Although I can't think of a case off
hand where you'd want to provisionally respond to a PRACK, specifically
allowing it is just asking for trouble between legitimate implementations.

> be responded to, you have no problem.

Except it may spawn another PRACK that spawns another PRACK ad infinitum.

> responses to PRACK itself, I am willing to discuss. I doubt its useful.

I'd vote for cutting it simply for the reason mentioned above.

James Undery