Re: [rtcweb] m=section recycling and a=mid

Christer Holmberg <christer.holmberg@ericsson.com> Thu, 19 September 2013 18:52 UTC

Return-Path: <christer.holmberg@ericsson.com>
X-Original-To: rtcweb@ietfa.amsl.com
Delivered-To: rtcweb@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C8C2C21F94FF for <rtcweb@ietfa.amsl.com>; Thu, 19 Sep 2013 11:52:24 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.222
X-Spam-Level:
X-Spam-Status: No, score=-4.222 tagged_above=-999 required=5 tests=[AWL=-0.974, BAYES_00=-2.599, HELO_EQ_SE=0.35, HTML_MESSAGE=0.001, J_CHICKENPOX_13=0.6, J_CHICKENPOX_14=0.6, J_CHICKENPOX_17=0.6, J_CHICKENPOX_18=0.6, J_CHICKENPOX_56=0.6, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id O3Cwga6fBYH1 for <rtcweb@ietfa.amsl.com>; Thu, 19 Sep 2013 11:52:18 -0700 (PDT)
Received: from mailgw1.ericsson.se (mailgw1.ericsson.se [193.180.251.45]) by ietfa.amsl.com (Postfix) with ESMTP id 6062421F949F for <rtcweb@ietf.org>; Thu, 19 Sep 2013 11:52:17 -0700 (PDT)
X-AuditID: c1b4fb2d-b7f738e000003ee3-0a-523b47dfd98a
Received: from ESESSHC024.ericsson.se (Unknown_Domain [153.88.253.124]) by mailgw1.ericsson.se (Symantec Mail Security) with SMTP id 75.74.16099.FD74B325; Thu, 19 Sep 2013 20:52:15 +0200 (CEST)
Received: from ESESSMB209.ericsson.se ([169.254.9.146]) by ESESSHC024.ericsson.se ([153.88.183.90]) with mapi id 14.02.0328.009; Thu, 19 Sep 2013 20:52:15 +0200
From: Christer Holmberg <christer.holmberg@ericsson.com>
To: Suhas Nandakumar <suhasietf@gmail.com>
Thread-Topic: [rtcweb] m=section recycling and a=mid
Thread-Index: AQHOtI5OlzgN5l68MU+Yf86f9mtTsJnNP/0ZgAAG7ICAACKcCw==
Date: Thu, 19 Sep 2013 18:52:14 +0000
Message-ID: <7594FB04B1934943A5C02806D1A2204B1C4A800E@ESESSMB209.ericsson.se>
References: <CAMRcRGRUufCBRg77DEEcqSvJ8uP2o2HU2GoJ23xu6wKPc9G3zA@mail.gmail.com> <7594FB04B1934943A5C02806D1A2204B1C4A7F29@ESESSMB209.ericsson.se>, <CAMRcRGT5T6FQSxgot4HObMW2r+z9id+BsXd0O8ZEauZunNmtzw@mail.gmail.com>
In-Reply-To: <CAMRcRGT5T6FQSxgot4HObMW2r+z9id+BsXd0O8ZEauZunNmtzw@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [153.88.183.20]
Content-Type: multipart/alternative; boundary="_000_7594FB04B1934943A5C02806D1A2204B1C4A800EESESSMB209erics_"
MIME-Version: 1.0
X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrMLMWRmVeSWpSXmKPExsUyM+Jvje59d+sgg47nphZr/7WzW+yc28Hs wOSxc9Zddo8lS34yBTBFcdmkpOZklqUW6dslcGV8nfiFreCGQ8X8I2fZGhj3m3YxcnJICJhI nFj1nA3CFpO4cG89kM3FISRwmFHixYpD7BDOEkaJ8323mboYOTjYBCwkuv9pgzSICGhJrF48 lwnEZhZQl7iz+Bw7iC0sYCyx8NkvFogaE4ldc9ewgbSKCDhJTHiuCxJmEVCV6Pz7nRXE5hXw lZg9qwesXEjgJqPEtCvhIDanQKDEtAlrmEFsRqDbvp9aA7VKXOLWk/lMEDcLSCzZc54ZwhaV ePn4HyuErShxdfpyqPp8iX83HrBA7BKUODnzCcsERtFZSEbNQlI2C0kZRFxP4sbUKWwQtrbE soWvmSFsXYkZ/w6xIIsvYGRfxciem5iZk15uuIkRGFEHt/zW3cF46pzIIUZpDhYlcd5NemcC hQTSE0tSs1NTC1KL4otKc1KLDzEycXBKNTAGakS+Y7W+dF/40XyzDWVN717OvzBzpm25uU7O jBse648xXzq655jDUhFe8fQdMQtkDwU7M0/e7XcqXkJG5gD/AgWBot7gKQIPnc85/3JibA5x 1msqV/6+/nq+w9zZe/mSOzSPbr7tMn3Ka6Z/nDPe90uHLkp5uOTs1wOXd03sqPNLW7RIl+GB EktxRqKhFnNRcSIAYxFZPnYCAAA=
Cc: "rtcweb@ietf.org" <rtcweb@ietf.org>
Subject: Re: [rtcweb] m=section recycling and a=mid
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Real-Time Communication in WEB-browsers working group list <rtcweb.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rtcweb>
List-Post: <mailto:rtcweb@ietf.org>
List-Help: <mailto:rtcweb-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rtcweb>, <mailto:rtcweb-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 19 Sep 2013 18:52:25 -0000

Correct.



Regards,



Christer

________________________________
From: Suhas Nandakumar [suhasietf@gmail.com]
Sent: Thursday, 19 September 2013 9:48 PM
To: Christer Holmberg
Cc: rtcweb@ietf.org
Subject: Re: [rtcweb] m=section recycling and a=mid

Hello Christer

  Completely agree with you

My point with the above examples was

  "recycling of m=line should take into account its existing BUNDLE membership and JS user's preference on requiring the added media track to be BUNDLED or not"

This would imply, as suggested by you,

  - remove the mid from a=group:BUNDLE line if the JS user doesn't want the new track to be BUNDLEd

 - or if the mid value is changed, then add the new mid value to the BUNDLE group if the JS user want's the new track to be BUNDLED

- or just retain the mid value and its BUNDLE membership for the new track, if it is going to be BUNDLEd


Cheers
Suhas







On Thu, Sep 19, 2013 at 9:24 AM, Christer Holmberg <christer.holmberg@ericsson.com<mailto:christer.holmberg@ericsson.com>> wrote:

Hi Suhas,



The mid attribute itself does not add an m- line to a BUNDLE group. The attribute value also needs to be listed in the group:BUNDLE attribute mid list.



So, if you want to re-use an m- line and mid attribute, but you don't want the m- line to be in the BUNDLE group, simply remove the mid from the mid list.



Regards,



Christer



________________________________
From: rtcweb-bounces@ietf.org<mailto:rtcweb-bounces@ietf.org> [rtcweb-bounces@ietf.org<mailto:rtcweb-bounces@ietf.org>] on behalf of Suhas Nandakumar [suhasietf@gmail.com<mailto:suhasietf@gmail.com>]
Sent: Wednesday, 18 September 2013 7:44 PM
To: rtcweb@ietf.org<mailto:rtcweb@ietf.org>
Subject: [rtcweb] m=section recycling and a=mid

After thinking about it a bit, I think there are some side effects associated with changing/not changing mid attribute of a re-cycled m= section and it being part of a BUNDLE group or not..

example

say , we have these video m=section part of BUNDLE group as below
a=group:BUNDLE 1, 2

m=video .....
a=mid:1
a=inactive

m=video .....
a=mid:2
a=sendrecv

Now If JS user adds a new video track and he wants it to be out of BUNDLE. If we recycle first video m=section and dont change mid attribute,  we end up BUNDLing even if the user dint want to

On the other hand, if we allowed mid value to be changed, we might end up UNBundling a video stream , when the user did want to BUNDLE them

So allowing a mid value to be changed or not should be tied to what the JS API is asking on behalf of the user


Any thoughts ?

Cheers
Suhas