Re: [MMUSIC] BUNDLE: SDP Offer Types

Paul Kyzivat <pkyzivat@alum.mit.edu> Mon, 03 June 2013 20:33 UTC

Return-Path: <pkyzivat@alum.mit.edu>
X-Original-To: mmusic@ietfa.amsl.com
Delivered-To: mmusic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id E0C5221E808B for <mmusic@ietfa.amsl.com>; Mon, 3 Jun 2013 13:33:53 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.437
X-Spam-Level:
X-Spam-Status: No, score=-0.437 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, FH_RELAY_NODNS=1.451, HELO_MISMATCH_NET=0.611, RDNS_NONE=0.1]
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 cWwu9WeIvZXg for <mmusic@ietfa.amsl.com>; Mon, 3 Jun 2013 13:33:38 -0700 (PDT)
Received: from qmta14.westchester.pa.mail.comcast.net (qmta14.westchester.pa.mail.comcast.net [IPv6:2001:558:fe14:44:76:96:59:212]) by ietfa.amsl.com (Postfix) with ESMTP id B861021E8099 for <mmusic@ietf.org>; Mon, 3 Jun 2013 13:24:27 -0700 (PDT)
Received: from omta03.westchester.pa.mail.comcast.net ([76.96.62.27]) by qmta14.westchester.pa.mail.comcast.net with comcast id jn071l0050bG4ec5EwQSB8; Mon, 03 Jun 2013 20:24:26 +0000
Received: from Paul-Kyzivats-MacBook-Pro.local ([50.138.229.164]) by omta03.westchester.pa.mail.comcast.net with comcast id jwQS1l00s3ZTu2S3PwQSvm; Mon, 03 Jun 2013 20:24:26 +0000
Message-ID: <51ACFB79.1080207@alum.mit.edu>
Date: Mon, 03 Jun 2013 16:24:25 -0400
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:17.0) Gecko/20130509 Thunderbird/17.0.6
MIME-Version: 1.0
To: Christer Holmberg <christer.holmberg@ericsson.com>
References: <7594FB04B1934943A5C02806D1A2204B1C37F87C@ESESSMB209.ericsson.se>, <51A8B059.7070705@alum.mit.edu> <7594FB04B1934943A5C02806D1A2204B1C38134B@ESESSMB209.ericsson.se>
In-Reply-To: <7594FB04B1934943A5C02806D1A2204B1C38134B@ESESSMB209.ericsson.se>
Content-Type: text/plain; charset="ISO-8859-1"; format="flowed"
Content-Transfer-Encoding: 7bit
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20121106; t=1370291066; bh=zb1xlpISYqahfUJMpKuR7VUrRk4rZfTAQ5gpd7fYNEE=; h=Received:Received:Message-ID:Date:From:MIME-Version:To:Subject: Content-Type; b=A2BERj1px+d/pXQEx06RLL7+Zf7vTkjVUxDsttU50IrixVVdggL8D1tZao90FPz5F AT+ob8098LTPjDw6SyYfu1nw7qFtDDvZ/OHDVtVFHkN5nF7sZpkPqN+KsrHb+Jd+jy q/s52Vtk6Rahk0okVuAWJU9C5AP/s8o8yWbJPSV3CRJEvXnKeg1Bej4tqulcs5zOVH pkUhylgm50m+nh+uXSRAY1Q8+ovS9YfA99JBcbqwZ9FDBc7sDj+dC51B4wuCgrL8oE aQpDIZj9DhlrrJSiAdBK/E+0XkH4J0IG6fIvgVvA2iyCgAkYNFNX+0T+Ih1+FDiunQ BqkJrF/XyhhKQ==
Cc: "mmusic@ietf.org" <mmusic@ietf.org>
Subject: Re: [MMUSIC] BUNDLE: SDP Offer Types
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Multiparty Multimedia Session Control Working Group <mmusic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/mmusic>, <mailto:mmusic-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/mmusic>
List-Post: <mailto:mmusic@ietf.org>
List-Help: <mailto:mmusic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/mmusic>, <mailto:mmusic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 03 Jun 2013 20:33:54 -0000

On 6/2/13 2:42 PM, Christer Holmberg wrote:
>
> Hi,
>
>>> I'll throw the ball out with suggesting the following ones:
>>>
>>> -*Bundle restart offer* (different port value, currently referred to as
>>> "first offer")
>>>
>>> The reason I use "restart" wording is because this is used, no matter
>>> whether in the beginning of the session or mid-session, to
>>> (re-)negotiate the usage of BUNDLE, and the bundle address information
>>> selection.
>>>
>>> -*Bundle sync offer* (identical port value, currently referred to as
>>> "second offer")
>>>
>>> The reason I used "sync" wording is because this is used to ensure that
>>> intermediaries have correct address information for each m- line.
>>>
>>> Keep in mind that we may even need to split the sync offer into more sub
>>> types, when we get into the details of adding new m- lines etc, but I'd
>>> like to agree a base to start from :)
>>
>> Above seems like a good start, but I'm still grappling with some things
>> and don't know how to talk about concisely:
>>
>> I understand that the next offer after a Bundle Restart Offer will
>> typically be a Bundle Sync Offer. But if there is another offer after a
>> Bundle Sync Offer, and it doesn't change anything about the bundle, then
>> is it still a Bundle Sync Offer?
>
> Currently, yes.

I agree that without adjusting the terminology this is the only right 
choice to make. But it is a little obscure. I'm not certain this needs 
to be improved, but I thought I would suggest that it might.

>> Also, I don't believe the above are mutually exclusive. If I send an
>> offer to add a new m-line to a bundle, and I give it distinct address
>> info so that the answerer may take it out of the bundle if needed, then
>> is that a Bundle Restart Offer or a Bundle Sync Offer? It seems to be a
>> bit of each. And of course there may be multiple bundles described by
>> the SDP, and these terms apply independently to each.
>>
>> Maybe we need a couple more terms for:
>>
>> - offer that adds a new m-line to bundle using the existing bundle
>>    address info.
>
> Technically that is a Bundle Sync Offer, but I DO agree that the wording is not good in this case - as it's not only about synchronization.
>
>> - offer that adds a new m-line to an existing bundle using unique
>>    address info.
>
> I agree that doesn't fit the current definitions.
>
> However, we will have to agree on whether we allow that in the first place, or whether the offerer will have to use 1) same address information or 2) different address information for ALL m- lines (Bundle Restart Offer).

Yes, we need to settle on whether either or both of these are permitted.

But I can think of reasons why I might wish to use either one, and no 
good reason not to allow both. So allowing both is my preference.

	Thanks,
	Paul