Re: [rtcweb] Review of draft-ietf-rtcweb-mdns-ice-candidates

Bernard Aboba <bernard.aboba@gmail.com> Sat, 15 September 2018 01:00 UTC

Return-Path: <bernard.aboba@gmail.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 9B301126F72 for <rtcweb@ietfa.amsl.com>; Fri, 14 Sep 2018 18:00:14 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.999
X-Spam-Level:
X-Spam-Status: No, score=-1.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.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 oT75OA0lH_bi for <rtcweb@ietfa.amsl.com>; Fri, 14 Sep 2018 18:00:12 -0700 (PDT)
Received: from mail-ua1-x936.google.com (mail-ua1-x936.google.com [IPv6:2607:f8b0:4864:20::936]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id B2F0F12008A for <rtcweb@ietf.org>; Fri, 14 Sep 2018 18:00:12 -0700 (PDT)
Received: by mail-ua1-x936.google.com with SMTP id c12-v6so7881378uan.3 for <rtcweb@ietf.org>; Fri, 14 Sep 2018 18:00:12 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=+JrP5Ctgfaa8FJIx6ThDWKYl3T+N498IdCODP9WwC2w=; b=e/8POwG3rVMqGp4pehTB2WNthIFS0qBcaDm84Ot58KnqVcfoCi3vPeyj9Cl46wef6U B8f5fvBMs2zOy9dlNf7Gx8nTYgTP3HTENKzsTCevKXTaVvD0m98waP3tnC19qVs+gNws acBC3m1O+wgJsFvX6r+TKWfYfs44cIGV1VSA3FsTfTN43vabYrcSza/iVnGaGQyDDhc8 eczugtBJFgXdCPuV2AS/1VcXMzGUw3jD0RA8Zc4Tyere8V+XrixayHRqoGyFjUSqo1eV ULeNy1I1qJJfJixy/ZNewLPz40GEnZtGbtSDidIf5kPKKWU0f+Vw13yPGNzIpAepWW6q b95Q==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=+JrP5Ctgfaa8FJIx6ThDWKYl3T+N498IdCODP9WwC2w=; b=TKw5Ar4nK+/t2aNa89RL64HlFHvjQPtgbftT4T1RCB+bX899Tx+Evma4jBge5hYDye 9foaF70cREIITAHhrvHwgPZqRnfMbhbt7GbuAbHh53gYLctNA/M27lnQkoQJXqiiTc3z O2bcL+uVVuu3sOuO7+if19z2HnwsBIOyDgExwLQDwU0pV72Eco+vRBveCP42qaCyO8iq w3D6SvzToTOB84Hqt7tcveCjucpyDDO8eDnP3pTBJMzYYKooYCfNofSeZ7d634j8Nkj/ B8yTqJ8NPc72L8UDLzHmgfaJ69tVj3BiGxkxpB5Zg0xCjIkmqYwVmkdjIfu0UmHP8nIx 8jyw==
X-Gm-Message-State: APzg51CaloFg0HzygfMCei6lCkPqds+pCxGU+CemKWN9QYxAhFGXZkgW 97WngJndxn5SrEKLA2GCwFWi6RWT7brRAwDr/G4=
X-Google-Smtp-Source: ANB0VdYxLLR8o9AR6q/wz3XShbAa1pNw7KxVprAv22Khe1+wwtWeblNvjYMN4F2M5m5kbPBYZP2sYQEZ4K7g2L9+Y4I=
X-Received: by 2002:ab0:4364:: with SMTP id k91-v6mr5214022uak.46.1536973211583; Fri, 14 Sep 2018 18:00:11 -0700 (PDT)
MIME-Version: 1.0
References: <CAOW+2dtkNjzS0DkD37SD=POtC2Nd6Xe=upyjvVoyBnnMw7qwbQ@mail.gmail.com> <E33840DD-0E89-40C2-9CFF-E1A798007C7B@westhawk.co.uk> <84F2BA5D-3B55-4B75-A8BE-C36852BA251C@gmail.com> <CANN+akYPTyA2tQrPRAKGd=DV4f8DWCFQknMJ8OnywoTdyZtn_Q@mail.gmail.com> <ACBC7AE0-FAB2-4E17-B4F6-9A0750BBEC13@gmail.com> <CANN+akYGaqFe23-0jWM7tj-Mi4x5sKm+TG-9_MSP=jj6_Eg55g@mail.gmail.com> <5763778B-0E13-44B6-AE5A-0BF011873F23@westhawk.co.uk> <CANN+akaSGC60KUm_uV7xbvCNBCs_1T7VHrP+k=nt5UosCGSkew@mail.gmail.com>
In-Reply-To: <CANN+akaSGC60KUm_uV7xbvCNBCs_1T7VHrP+k=nt5UosCGSkew@mail.gmail.com>
From: Bernard Aboba <bernard.aboba@gmail.com>
Date: Fri, 14 Sep 2018 18:00:00 -0700
Message-ID: <CAOW+2dtfhrdwpt4BCLWy3cfBGPpj==nooyWNs=mzfedffh_Oog@mail.gmail.com>
To: youenn fablet <youennf@gmail.com>
Cc: RTCWeb IETF <rtcweb@ietf.org>, T H Panton <thp@westhawk.co.uk>
Content-Type: multipart/alternative; boundary="0000000000004e49b00575de76b2"
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtcweb/hUkhzArQuX2L2iUWkV502b-BXM4>
Subject: Re: [rtcweb] Review of draft-ietf-rtcweb-mdns-ice-candidates
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: Sat, 15 Sep 2018 01:00:15 -0000

On Fri, Sep 14, 2018 at 5:42 PM youenn fablet <youennf@gmail.com> wrote:

>
> In that case, the camera/MUX device might act as a STUN/TURN server.
>

[BA] In the usage I have seen the sender is a PC or Mac brought in to run
the meeting; STUN/TURN servers are run by an infrastructure group and are
separate.

>
> It will probably expose all of its host candidates. Ditto if sender is a
> browser since getUserMedia is on.
> I would think the connection to be feasible through peer reflexive
> candidates without the receiver to expose its own host candidates to
> JavaScript.
>

[BA] The STUN/TURN servers are often placed in the DMZ rather than on the
corpnet so using addresses other than host candidates will result in
hairpinning or unnecessary relaying.

>
>> Is the sender sending the media to each receiver or are there some
>> receivers acting as senders to other receivers?
>>
>>
[BA] For a large meeting, there is typically a conference server (SFU)
which forwards video and mixes or forwards audio to the receivers, most of
whom never send.