Re: [rtcweb] Working Group Last Call for draft-uberti-rtcweb-rfc8829bis-01.txt

Christer Holmberg <christer.holmberg@ericsson.com> Mon, 01 November 2021 13:29 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 772103A12F4 for <rtcweb@ietfa.amsl.com>; Mon, 1 Nov 2021 06:29:26 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.101
X-Spam-Level:
X-Spam-Status: No, score=-2.101 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001, RCVD_IN_MSPIKE_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (1024-bit key) header.d=ericsson.com
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 ek28EShWNsOF for <rtcweb@ietfa.amsl.com>; Mon, 1 Nov 2021 06:29:22 -0700 (PDT)
Received: from EUR02-HE1-obe.outbound.protection.outlook.com (mail-eopbgr10072.outbound.protection.outlook.com [40.107.1.72]) (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 9D60E3A1267 for <rtcweb@ietf.org>; Mon, 1 Nov 2021 06:29:21 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=B2NuUK4vzw9ZMf1xzDD/6YHftzwA44zDL++otEvbOYCzMGTY5pSQI4dgXULzOBCHgtJ5iM8haXNMCUrK43xOgfHIcGLXk4Nrylk/Hr+CJPqvg4pwaFNGb92Hw3c5GyX6isemLVYlUsScwj5a8pB8fgupSrNhGYDKPaWY/w8PJjMf8tWvt79BCjKisC9jQq9d1W9fiKjBR5Rr3aCgVyWnzEjb8eepCq8P3H/fdTY7fnIIL2d15SH7T7buU51xiDMpX/+8VQBF+MjWIjP+gRdoQYWU1GwUCBPelY5oNYv4CLfk4E5dh7AAw4xsemH2e9TJ2FtHDEzC9FwlbK+LSH0IEA==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=8IWLZkQ0GpCJjWF/QJWqceqEzp/elAH32Hq8l7Txcs4=; b=gqeojH/WDZHUnm664V2zpQvbjwyzHFNH1KinFd9x5dnwxj1JQ5+oP5NLWBRHAA94MCwz7nWAbMWBvE7/wEc/MnCU1uGBlzQxkVSLzn6DXySbxV8DMTTiLyli0t8//RGdP8k8qjf/dhAJpqSp/xDuVpz98VkxJ2oqf2G5pH2rWZy8PyzuJTs7neGx2qejyAVLyk31ddhOYGm+Ex5WiW5s8eFFeKGK3PJHv7o6hTcnVxPRmULRT/Tm+USV1Yv/n+bTY7+WolW0JdtFrbbBwo1DHhoyCGJvuQbfsBMFkjMkPOALuBT0cO/PiO7ZaVa7TLpzyELVHrEGxwjKV8LuZqebxQ==
ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=ericsson.com; dmarc=pass action=none header.from=ericsson.com; dkim=pass header.d=ericsson.com; arc=none
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ericsson.com; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=8IWLZkQ0GpCJjWF/QJWqceqEzp/elAH32Hq8l7Txcs4=; b=b485BuNUyWVEh77dNx44ll3MRCmgnjcfLPTC48LYMLvNP7RWh+NrPnZ85lr0SF7UpgNY/94RRi/ZL8G/+i3nZqhLlV6CgkiWR2JtomZoHiTH/NXvyH6ixoJ+UYpfJ7jCMwzd+pRFlc3hzNoHuDehUzMLmtUDfglSONdcvV8xYaY=
Received: from HE1PR07MB4441.eurprd07.prod.outlook.com (2603:10a6:7:9f::27) by HE1PR07MB3097.eurprd07.prod.outlook.com (2603:10a6:7:32::31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4669.4; Mon, 1 Nov 2021 13:29:17 +0000
Received: from HE1PR07MB4441.eurprd07.prod.outlook.com ([fe80::44b6:1bcd:7be6:b173]) by HE1PR07MB4441.eurprd07.prod.outlook.com ([fe80::44b6:1bcd:7be6:b173%2]) with mapi id 15.20.4669.009; Mon, 1 Nov 2021 13:29:17 +0000
From: Christer Holmberg <christer.holmberg@ericsson.com>
To: Justin Uberti <juberti@alphaexplorationco.com>
CC: Roman Shpount <roman@telurix.com>, Justin Uberti <justin@uberti.name>, RTCWeb IETF <rtcweb@ietf.org>
Thread-Topic: [rtcweb] Working Group Last Call for draft-uberti-rtcweb-rfc8829bis-01.txt
Thread-Index: AQHXylf+AMpeemP+/Umn4mKjUNsZYKvlgWaAgAAD7wCAAFFxgIAEazaAgAAJNoCAAAJcgIAARq+AgAAFWYCAAD0AgIABPVtQgABvX4CAAHTpwIABOTMAgAB5B30=
Date: Mon, 01 Nov 2021 13:29:17 +0000
Message-ID: <HE1PR07MB4441B47E50789CBBE1BCB3F5938A9@HE1PR07MB4441.eurprd07.prod.outlook.com>
References: <CA+9kkMA_8jCGeb_QkhVz2JLRYGbq+MkGG9wJ2k0vo6noDDkkQA@mail.gmail.com> <CAD5OKxvK_CUnHc0kqNNVUkOHgtUqL=vjdUTLqL+RJpZBtWL+4A@mail.gmail.com> <CALe60zAC7VA6y5oLkC9HBRQUhJyY73Atbfmm1KVKw=hyPqD=2Q@mail.gmail.com> <CAD5OKxvi7t6ug9xsjqiB35hTWNJ0D04XK5w=njZ8hB_6UpRzEQ@mail.gmail.com> <CAOLzse14Qkn+EiO3xHfGi2QmBvH0M=fQD-SmA9TXsfmHjPKLfQ@mail.gmail.com> <CAD5OKxtrBFsZBGUKtB6MNwMrPnzE9NSyQWrjXGjzE8PkYmj8Bw@mail.gmail.com> <CAOLzse2L=Xu=Y944B9mwURQ6VP__KuEp-C_-xNw0MhNLv2LoCw@mail.gmail.com> <CAD5OKxtr==_dwW7-JbjP7abxNAityukfpHS5xK6vf-YuTADd+A@mail.gmail.com> <CAOLzse1-8cTg=GE2ndQ3tpVa25wzNqkOy6J6M30X=dN2Ejnvyg@mail.gmail.com> <CAD5OKxs5wCQuaaC1sL+Zi2iwMhnzexTh89HVOWc2jLTBGoyD9A@mail.gmail.com> <HE1PR07MB44413791A6AC8D20349BEBF793889@HE1PR07MB4441.eurprd07.prod.outlook.com> <CAD5OKxtyCUgJP2CjPkyNBuDp3_N-42J15AvB==36edujJsjh-g@mail.gmail.com> <HE1PR07MB4441051506F5A2E16A2C902993899@HE1PR07MB4441.eurprd07.prod.outlook.com> <CAOLzse1H6OgtpkbMNXVSJFpvWoBoJeVp3Rg37x7d24LZ7A+Pmw@mail.gmail.com>
In-Reply-To: <CAOLzse1H6OgtpkbMNXVSJFpvWoBoJeVp3Rg37x7d24LZ7A+Pmw@mail.gmail.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
suggested_attachment_session_id: 039f4edd-ff8d-7c7b-c1d3-98743c282fe1
authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=ericsson.com;
x-ms-publictraffictype: Email
x-ms-office365-filtering-correlation-id: bae664a6-a124-4f79-eea0-08d99d3b9afd
x-ms-traffictypediagnostic: HE1PR07MB3097:
x-microsoft-antispam-prvs: <HE1PR07MB3097D3A6CA307D3BEAB3A6C3938A9@HE1PR07MB3097.eurprd07.prod.outlook.com>
x-ms-oob-tlc-oobclassifiers: OLM:10000;
x-ms-exchange-senderadcheck: 1
x-ms-exchange-antispam-relay: 0
x-microsoft-antispam: BCL:0;
x-microsoft-antispam-message-info: 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
x-forefront-antispam-report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:HE1PR07MB4441.eurprd07.prod.outlook.com; PTR:; CAT:NONE; SFS:(4636009)(366004)(9686003)(76116006)(8936002)(5660300002)(82960400001)(6506007)(8676002)(508600001)(55016002)(186003)(38100700002)(54906003)(64756008)(316002)(52536014)(38070700005)(2906002)(66556008)(66476007)(86362001)(7696005)(6916009)(83380400001)(19627405001)(122000001)(66446008)(33656002)(71200400001)(66946007)(4326008)(44832011); DIR:OUT; SFP:1101;
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: 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
Content-Type: multipart/alternative; boundary="_000_HE1PR07MB4441B47E50789CBBE1BCB3F5938A9HE1PR07MB4441eurp_"
MIME-Version: 1.0
X-OriginatorOrg: ericsson.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: HE1PR07MB4441.eurprd07.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: bae664a6-a124-4f79-eea0-08d99d3b9afd
X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Nov 2021 13:29:17.6691 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 92e84ceb-fbfd-47ab-be52-080c6b87953f
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: psZ8QXNiaIXisN7BKsyMXL+0D/xtchFUcxU2TZOmypf+lo2aonLxu5j+ojTZEFZN++cGjuHHkGwExbuNDl0nlQeNL4efh389v88c83rEByk=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: HE1PR07MB3097
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtcweb/vjbj6seFYCpGaurpYcMznH7HBxU>
Subject: Re: [rtcweb] Working Group Last Call for draft-uberti-rtcweb-rfc8829bis-01.txt
X-BeenThere: rtcweb@ietf.org
X-Mailman-Version: 2.1.29
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: <https://mailarchive.ietf.org/arch/browse/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: Mon, 01 Nov 2021 13:29:27 -0000

Hi,


>1. Make subsequent offers valid initial offers. This means adding some language explaining how the endpoint processing initial offer can detect that m= lines cannot be unbundled. Even if we add this language it will have backwards compatibility issues with anything that has not implemented it.



I don’t agree with that suggestion. Because, in that case we could have done it from the beginning, as a general rule, without using port zero. But there were reason we chose not to allow shared addresses (with non-zero port values) in initial offers.

>We did come up with a=bundle-only mechanism to ensure backwards compatibility, and none of us want to revisit that decision. However, I do think that it would be consistent with Postel's Principle for the
> answerer to properly handle the case where a 3PCC offer ends up with a shared address, rather than failing simply because the offer does not appear to be an initial offer.

I don't agree with that. Again, that is why we did not define it to begin with. When this was discussed, people indicated that even in cases where an answerer would accept the offer, it is not possible to predict how the answer would look like.

Also, keep in mind that the answerer may not know that the offer is for 3PCC. It may just see an initial offer.




>2. Make endpoints generate subsequent offers that are valid initial offers in 3PCC scenarios. This is what draft 8843 bis does.



Correct.



However, keep in mind that it is not only about how to encode the port numbers and bundle-only attributes. Sending an initial offer also comes with a set of procedures. Some of those (e.g., ICE)  I assume you will have to do anyway, as the remote endpoint changes.



>I would even be fine with webrtc endpoint not doing anything and adding a note to JSEP telling the 3PCC application to "fix" the offer and add m= port zero and bundle-only attributes when it is sending subsequent offers as initial offers to a new end point.



I would be fine adding such text to JSEP. It could be an additional sentence to the existing text.



(However, I still would not say “sending subsequent offers as initial offers”. I would say “create and send an initial offer based on a received subsequent offer”, or something like that.)

>This might turn out to be the simplest option, but as noted before, it will require several SDP changes and will be somewhat error-prone as a result (assuming anyone implements this at all). Accordingly I think #1 above is the least bad choice.

I don't agree with suddenly allowing (read: specify in the standard that it is ok) something that we agreed that we are not going to do more or less from day one, and that has never considered later during the process either.

---

The PROBLEM is that we have two endpoints, where one sends a subsequent offer, and the other one expects an initial offer. What do you normally do when you have that kind of problem? You use an SBC/B2BUA. In this case that SBC/B2BUA would be the 3PCC controller.

So, my suggestion would be to remove the SHOULD text from 8843bis, and simply add a note somewhere (in 8843bis and/or 8829bis) which describes the issue and says that the 3GPP controller needs to modify the offer accordingly.

Regards,

Christer