Subject: [Sipping] Update to 3pcc

From: Jonathan Rosenberg <[email-masked]>
Date: Tue, 08 Jul 2003 13:51:46 -0400

Folks,

You may have noticed that I posted an update to the 3pcc spec:

http://www.jdrosen.net/papers/draft-ietf-sipping-3pcc-04.txt
http://www.jdrosen.net/papers/draft-ietf-sipping-3pcc-04.html
http://www.ietf.org/internet-drafts/draft-ietf-sipping-3pcc-04.txt

The update is based on comments received from IESG while reviewing the 
draft. In particular, there were problems with the usage of 0.0.0.0 to 
  imply that no media nor RTCP should be sent. This IP address is not 
meant for that purpose. Rather, the .invalid TLD is much better 
suited. So, I changed the draft to make use of .invalid in flows where 
the controller doesnt want media to be sent.

Now, there are some concerns with that which folks need to be aware of:

1. It is at odds with RFC 3264, which actually recommends 0.0.0.0. In 
fact, the problem is really with RFC 3264, NOT 3pcc. However, 3264 is 
done, and this one isnt. I logged a bug against RFC 3264 on this, and 
we'll need to work on a way to transition folks towards using .invalid 
and not 0.0.0.0.

2. One the premises of 3pcc is that it should be compatible with any 
UA that is RFC 3261 compliant. If a controller uses .invalid in the 
SDP, I am not sure what a SIP endpoint would do. I don't believe 
anything in RFC 3264 or in SIP talks about handling the case where 
there is an issue with a domain name in the SDP. As such, if you use 
.invalid, there could be interop problems. The document mentions this.

Comments or questions welcome.

Thanks,
Jonathan R.
-- 
Jonathan D. Rosenberg, Ph.D.                600 Lanidex Plaza
Chief Technology Officer                    Parsippany, NJ 07054-2711
dynamicsoft
[email-masked]                     FAX:   (973) 952-5050
http://www.jdrosen.net                      PHONE: (973) 952-5000
http://www.dynamicsoft.com

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From: Sean Olson <[email-masked]>
Date: Tue, 8 Jul 2003 11:05:27 -0700 (PDT)

This is a huge interop issue. Is .invalid to be the
recommendation going forward or is this a stopgap
measure? Hopefully SDPng addresses this more directly.

--- Jonathan Rosenberg <[email-masked]>
> Comments or questions welcome.

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From: Magnus Westerlund <[email-masked]>
Date: Wed, 09 Jul 2003 08:52:58 +0200

Hi, Sean

> measure? Hopefully SDPng addresses this more directly.

Have you communicated this need to the SDPng authors? The main issue 
with SDPng is the lack of interest and review. I think they would 
appreciate the feedback. And the list to discuss SDPng is MMUSIC's.

Best Regards

Magnus Westerlund

Multimedia Technologies, Ericsson Research EAB/TVA/A
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