Subject: RE: [Sip] Media goes draft

From: "Zmolek, Andrew (Andrew)" <[email-masked]>
Date: Thu, 26 Jul 2001 14:26:13 -0600

The concept sounds great, but this could be quite an operation and the
timing might be an issue right now. And while allowing for SDPng is
good, we also run the risk of ending up at a point where we might allow
for all kinds of SDP replacement candidates which could create more
interoperability islands over time. 

If we take this approach, let's make sure we're convinced the reward
outweighs the risks. If so, I'm all for it.

--Andy Zmolek
    Technology & Standards Engineer
      CTO Standards
        Avaya Inc.

            [email-masked]
              +1 720 444 4001

-----Original Message-----
From: Christer Holmberg [mailto:[email-masked]]
Sent: Thursday, July 26, 2001 5:01 AM
To: [email-masked]
Subject: [Sip] Media goes draft

Hi,

A small idea...

We now have a number of SIP extensions, defined in separate drafts, and
things like compression and security will also be outside the core bis
document. This way is very good and flexible, and the bis doesn't have
to be changed every time there is a change elsewhere.

I have been thinking of this before, and it came back now when the early
media draft was released: why not make the whole SIP media handling as a
separate draft? Some advantages I see:

1. Today we have SDP, tomorrow maybe SDPng, so we still would have to
write a separate document for that, or update the RFC2543 again.

2. Annex B is IP specific, even IPv4 specific, so we still will have to
write separate documents how SIP uses SDP for IPv6 bearers/ATM
bearers/whatever-future bearers (I KNOW there allready are separate
documents some of these).

3. It would be possible to go into the handling of EACH media- and
bearer type much more in detail.

4. All media handling, including services like call hold, media
modification and early media, would be in the same document.

I know that doing this is not very high on the priority list, but I also
don't think that it would take very much time (to start with, we only
have to cut-paste Annex B...:).

Just an idea. Comments?

Christer Holmberg
Ericsson Finland

Ps. I think that doing this would also make things more clear for those
who still think that SIP is a protocol used to transport media :)

---

From: Christer Holmberg <[email-masked]>
Date: Fri, 27 Jul 2001 08:03:37 +0300

Hi Andy,

Thanks for your comments! A small clarification, though.

I did not mean that we have to include SDPng from the beginning - I
think it's enough to start with SDP. SDPng, and whatever other SDP
"replacements" that may come up in future, can be added later, or
written in separate drafts. The point is that it wouldn't affect the
core SIP specification (ie RFC2543).

Regards,

Christer Holmberg
Ericsson Finland

"Zmolek, Andrew (Andrew)" wrote:
> good, we also run the risk of ending up at a point where we might
> allow for all kinds of SDP replacement candidates which could create
> more interoperability islands over time.
>