Re: [MMUSIC] Comments on IESG Changes in the -cs draft ? [Fwd: Protocol Action: 'Session Description Protocol (SDP) Extension For Setting Audio and Video Media Streams Over Circuit-Switched Bearers In The Public Switched Telephone Network (PSTN)' to Proposed Standard (draft-ietf-mmusic-sdp-cs-21.txt)]

["Miguel A. Garcia" <[e-mail]>]

Hi Hadriel:

As far as I remember, the history of the three mechanisms is kind of fuzzy. At some point in time in the past, 3GPP hadn't decided on the architecture to enable CS calls over SIP/SDP, and they were looking into it. The mechanisms were envisioned by the authors and comments on the mailing list, and put at 3GPP's disposal for a choice.

I concur with  your concern that just because we mandate to implement the 3 of them, these are not going to be implemented. I don't have any problem in removing from the draft those mechanisms that we envision they won't be used.

/Miguel

On 10/08/2013 1:28, Hadriel Kaplan wrote:

Wow.  I can kinda understand why they'd say that (interop reasons, presumably), but that's a big deal.  The 3 mechanisms are very different, with very different architectural and deployment implications.  I have a very hard time believing any of us would truly implement all three.  In fact, I don't truly believe anyone would.

So... I hate to do this, but can the authors summarize the history of how we got 3 mechanisms to begin with, and who would really implement them all?

Or to put it another way, instead of specifying all 3, would it be impossible to take a step back and reconsider the real motivating use-case (which as far as I know is 3GPP), and only specify the one they need/use?

-hadriel


On Aug 9, 2013, at 6:10 PM, Flemming Andreasen <[e-mail]> wrote:

Greetings MMUSIC

As you can see per the below, the IESG approved the Circuit-Switched Bearers draft for publication, however before doing so, they requested a couple of changes. The resulting approved document can be found at http://tools.ietf.org/html/draft-ietf-mmusic-sdp-cs-21" rel="nofollow">http://tools.ietf.org/html/draft-ietf-mmusic-sdp-cs-21

One of the changes introduced resulted in all 3 correlation mechanisms now being mandatory-to-implement (previously they were not):
<quote>
   Implementations MUST support the three correlation mechanisms
   specified in 
Section 5.2.3.2, Section 5.2.3.3 and Section 5.2.3.4
,
   and SHOULD include all supported mechanisms the initial Offer.

</quote>
Since this is a non-trivial change that has not been discussed by the WG (and we know of at least one person having expressed concerns with it off-line), we are hereby solicting the WG participants for input on changes introduced as a result of the IESG review with a focus on the above. In doing so, please keep in mind that we are developing standards that work in the general Internet. 


The following URL provides a diff-file showing the changes resulting from the IESG review:
    http://tools.ietf.org/rfcdiff?url1=draft-ietf-mmusic-sdp-cs-18.txt&url2=draft-ietf-mmusic-sdp-cs-21.txt" rel="nofollow">http://tools.ietf.org/rfcdiff?url1=draft-ietf-mmusic-sdp-cs-18.txt&url2=draft-ietf-mmusic-sdp-cs-21.txt

Comments are due by August 23 (two weeks from today)

Thanks 

-- Flemming (MMUSIC co-chair)



-------- Original Message --------
Subject:	[MMUSIC] Protocol Action: 'Session Description Protocol (SDP) Extension For Setting Audio and Video Media Streams Over Circuit-Switched Bearers In The Public Switched Telephone Network (PSTN)' to Proposed Standard (draft-ietf-mmusic-sdp-cs-21.txt)
Date:	Mon, 1 Jul 2013 11:56:23 -0700
From:	The IESG <[e-mail]>
To:	IETF-Announce <[e-mail]>
CC:	mmusic chair <[e-mail]>, mmusic mailing list <[e-mail]>, RFC Editor <[e-mail]>

The IESG has approved the following document:
- 'Session Description Protocol (SDP) Extension For Setting Audio and
   Video Media Streams Over Circuit-Switched Bearers In The Public
   Switched Telephone Network (PSTN)'
  (draft-ietf-mmusic-sdp-cs-21.txt) as Proposed Standard

This document is the product of the Multiparty Multimedia Session Control
Working Group.

The IESG contact persons are Gonzalo Camarillo and Richard Barnes.

A URL of this Internet Draft is:

http://datatracker.ietf.org/doc/draft-ietf-mmusic-sdp-cs/" rel="nofollow">http://datatracker.ietf.org/doc/draft-ietf-mmusic-sdp-cs/





*Technical Summary
*

The document describes use cases, requirements, and protocol extensions
for using the Session Description Protocol (SDP) Offer/Answer model for
establishing audio and video media streams over circuit-switched bearers
in the Publich Switched Telephone Network (PSTN)

*Working Group Summary
*

The WG had some discussion around the format to use for E.164 numbers
and whether to align this with the existing definition in RFC 3108. The
RFC 3108 definition was seen as deficient and the WG agreed it was
better to align with relevant parts of the tel URI format defined in RFC
3966, not least since SDP address types are defined in the context of a
particular network type, and hence RFC 3108 compatibility is not a
concern (the implication is that the "E164" address type may differ
between network types in SDP).

*Document Quality
*

There are currently no known implementations of the draft, however the
draft is a dependency for 3GPP, so future implementations are expected.

The document has received good overall review in the WG, some of which
resulted in changes to the detailed specification. The document has been
reviewed in detail several times, including of the last few versions.
The major contributors to these as well as earlier discussions are
listed in the Acknowledgements section of the document.


*Personnel
*

Document Shepherd: Flemming Andreasen
Responsible AD: Gonzalo Camarillo 
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.




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-- 
Miguel A. Garcia
[phone]
Ericsson Spain