Subject: [Sipping] Comments on draft-sawada-sipping-sip-offeranswer-01.txt

From: Gonzalo Camarillo <[email-masked]>
Date: Thu, 06 Jul 2006 12:48:03 +0300

Hi,

a few comments on the draft below:

http://www.ietf.org/internet-drafts/draft-sawada-sipping-sip-offeranswer-01.txt

First of all, the draft needs to be very clear about its scope. This
draft's scope should be to clarify aspects of how SIP uses the
offer/answer model. Consequently, the idea will be to publish it at some
point as an informational RFC. This means that this draft should not
contain normative language. So, the reference to RFC 2119 should be
removed. An explanation along the lines of this paragraph at the
beginning of the draft would not hurt either.

In the process of discussing this draft, we will most likely find
offer/answer aspects that are underspecified or that need to be fixed (a
few cases have already been identified in the mailing list discussions).
The role of this draft is not to fix those. We have to options. We can
document the issue and publish this draft or we can generate a normative
document fixing the issue, and only then publish this draft referencing
that new document. The best option will depend on the particular case at
hand.

A comment on the Introduction. It says: "Unless defined in an RFC
explicitly as an offer or an answer, except ones in non-reliable
provisional response to INVITE request, a session description should not
be included in SIP messages to avoid confusions".

As pointed out in Section 1.3, some SIP messages can carry session
descriptions that are not offers or answers. Therefore, the paragraph
above needs to be rephrased.

Regarding the interest of the SIPPING WG to work on this document, based
on the mailing list discussions, it is clear that there is a great deal
of interest to clarify the topics this draft deals with. So, this draft
is a very good candidate to become a SIPPING working group item in the
future (as soon as we finish some of the stuff we currently have on our
plate). This is an excellent example of how a draft can be discussed and
even adopted as a WG item without a face-to-face presentation.

Cheers,

Gonzalo

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---

From: Takuya Sawada <[email-masked]>
Date: Fri, 7 Jul 2006 10:37:50 +0900

Hi,

> beginning of the draft would not hurt either.
I feel we have reached the consensus that the scope of this draft is for
clarification of the usage and does not include any extension to SIP.
That is, it should be an informational RFC.

I agree to remove the reference to RFC 2119. We do not use no capital
keywrods like "MUST" or "SHOULD" in the draft.

> that new document. The best option will depend on the particular case at
I prefer the former option.
It is also important to make some issues clear and document them before
we tackle them.
> above needs to be rephrased.
I think we can just remove the above sentense.
How to avoid confusion is described inside this draft. 
Such a statement does not need to be here.
> even adopted as a WG item without a face-to-face presentation.
We will update the draft along with the discussions held in the SIPPING ML,
as an individual draft.
Then, please discuss whether to adopt it as a WG item and how/when.

> Gonzalo
Thanks,

Takuya

--------
Takuya Sawada
KDDI Corporation (KDDI)
Garden Air Tower, 3-10-10, Iidabashi, 
Chiyoda-ku, Tokyo 102-8460, Japan
Tel: +81-3-6678-2997
Fax: +81-3-6678-0286
[email-masked]