Re: [MMUSIC] draft-holmberg-mmusic-t140-usage-data-channel - multi-party

Paul Kyzivat <pkyzivat@alum.mit.edu> Tue, 27 August 2019 18:39 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 36D3B120895 for <mmusic@ietfa.amsl.com>; Tue, 27 Aug 2019 11:39:55 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -4.2
X-Spam-Level:
X-Spam-Status: No, score=-4.2 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id DhqHMbC6WArV for <mmusic@ietfa.amsl.com>; Tue, 27 Aug 2019 11:39:52 -0700 (PDT)
Received: from outgoing-alum.mit.edu (outgoing-alum.mit.edu [18.7.68.33]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 2D235120879 for <mmusic@ietf.org>; Tue, 27 Aug 2019 11:39:52 -0700 (PDT)
Received: from Kokiri.localdomain (c-24-62-227-142.hsd1.ma.comcast.net [24.62.227.142]) (authenticated bits=0) (User authenticated as pkyzivat@ALUM.MIT.EDU) by outgoing-alum.mit.edu (8.14.7/8.12.4) with ESMTP id x7RIdnG3003688 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT) for <mmusic@ietf.org>; Tue, 27 Aug 2019 14:39:50 -0400
To: mmusic@ietf.org
References: <49749CEF-41E8-4E87-8CC6-938DBDA0CEE7@ericsson.com> <0DA1248C-41FC-4155-A578-29A19883857C@ericsson.com> <a91850b9-6e86-058f-dddd-3f856bcd6710@omnitor.se> <DBC532B8-38DC-4140-B7C4-0B6853F0EF77@ericsson.com> <6fcf46a6-544d-027c-97c7-5c0e08caa555@omnitor.se> <HE1PR07MB3161A9A0C696B9636BBD380C93A70@HE1PR07MB3161.eurprd07.prod.outlook.com> <6484f305-0c38-4178-ee12-05a7dc38364f@omnitor.se> <HE1PR07MB31617F7C6E81EF041716749793A60@HE1PR07MB3161.eurprd07.prod.outlook.com> <ee4e6d3a-e984-15c7-dcaa-571be0e726b8@omnitor.se> <HE1PR07MB3161CC8F09E178F2E982E5AC93A60@HE1PR07MB3161.eurprd07.prod.outlook.com> <a5057f34-f222-e290-df88-da6e96d56294@omnitor.se> <A48CA18B-567B-46B9-9501-4FF65D4C8CAE@ericsson.com> <6c6d13ad-8699-73b9-f8aa-8ef16c5b3451@omnitor.se> <FB8E32BC-89C2-41CE-BBE1-81C4E7A56E77@ericsson.com> <f59f9335-329d-7b26-dec3-0898051040ce@omnitor.se> <VI1PR07MB31675A98F9B08A07D984369293A10@VI1PR07MB3167.eurprd07.prod.outlook.com> <084e8ee3-56fe-b764-fbbe-8afbee72e8e3@omnitor.se>
From: Paul Kyzivat <pkyzivat@alum.mit.edu>
Message-ID: <255759e0-c2c0-981a-e530-e05f7553c26e@alum.mit.edu>
Date: Tue, 27 Aug 2019 14:39:49 -0400
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:60.0) Gecko/20100101 Thunderbird/60.8.0
MIME-Version: 1.0
In-Reply-To: <084e8ee3-56fe-b764-fbbe-8afbee72e8e3@omnitor.se>
Content-Type: text/plain; charset="windows-1252"; format="flowed"
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Archived-At: <https://mailarchive.ietf.org/arch/msg/mmusic/cvt7COzmP0Spc_DSgumo35BWEkQ>
Subject: Re: [MMUSIC] draft-holmberg-mmusic-t140-usage-data-channel - multi-party
X-BeenThere: mmusic@ietf.org
X-Mailman-Version: 2.1.29
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: <https://mailarchive.ietf.org/arch/browse/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: Tue, 27 Aug 2019 18:40:04 -0000

On 8/26/19 3:59 PM, Gunnar Hellström wrote:

> 4. A multi-party server S, combining a number of sources into one call 
> to a participant A, with real-time text from each other participant 
> (B,C,...) communicated in just one T140 data channel between S and A.  
> There is a need to indicate source for each T140block sent to A. We 
> currently have no way specified for that. An extension of T.140 could do it.

Is there a reason to ever do this?

In audio and video the "mixing" actually does something irreversible. 
And it takes real work to do it, and doing so reduces the bandwith 
considerably over what is required to transmit the individual streams.

For RTT none of that is true. There is very little impact in bandwidth 
or processing in transmitting them all as separate channels.

So why not just say "don't do that"?

	Thanks,
	Paul