IETF Logo Mail Archive

Re: [rtcweb] JSEP question: How to set up simulcast for server-originated calls?

Iñaki Baz Castillo <ibc@aliax.net> Mon, 05 November 2018 22:57 UTC

Return-Path: <ibc@aliax.net>
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 AFC45130DC7 for <rtcweb@ietfa.amsl.com>; Mon, 5 Nov 2018 14:57:50 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.902
X-Spam-Level:
X-Spam-Status: No, score=-1.902 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_MED=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, 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=aliax-net.20150623.gappssmtp.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 ORhTvF_jrNgn for <rtcweb@ietfa.amsl.com>; Mon, 5 Nov 2018 14:57:48 -0800 (PST)
Received: from mail-vk1-xa2f.google.com (mail-vk1-xa2f.google.com [IPv6:2607:f8b0:4864:20::a2f]) (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 9E783128CE4 for <rtcweb@ietf.org>; Mon, 5 Nov 2018 14:57:48 -0800 (PST)
Received: by mail-vk1-xa2f.google.com with SMTP id n126so2226120vke.12 for <rtcweb@ietf.org>; Mon, 05 Nov 2018 14:57:48 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aliax-net.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=tVIEwfKcYDxD46meOmGZXDGAcc0cITOPeHQ1rNUdm5c=; b=EtVrs6GIAWKREMdsc2KWhp7H7ue73P9GW+3/CHwzS+ktH+TI2ALKOOHEmAE7/ac+SR sAg6lka07RpV17N2kn+fT643k6URFKk9ykDYmYv7XjsWaocCsBx57GLjCzVo9lxulo4m mLD2+37R5MhzXffmWdBKz1ZjHX3mz+Fwgzw7Wa9tGpkzRqTU6tacalXHXvTAcBfv6lHO 8sCAzWh0ycVHJknFpxCS7mpjaqD5v9LpIXo2jTRrTWMRagFWKPvu19quIlIbOsc+xwsJ tPxjj8OZ65GxlfEnbmhEufcfG19EM7Kr90zc9UPbZ3YFZX0Vt8qtuYpucNQLRJUIMc78 hRzg==
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:content-transfer-encoding; bh=tVIEwfKcYDxD46meOmGZXDGAcc0cITOPeHQ1rNUdm5c=; b=W8Bih4uqN90OCW/5EUjq9vZRNNum226ZT+rYt0wxSWJuCf22PHV4w7mUFUL7OjSEJA zf1gpes/pX12a4lLhsxxyBfalP2BvKQ4gOt6g5WQTC4Ql6/H1vb+VeHxzQUEHqB9FnsU S0uRQHd3SBp6DAFk//74v/tpjWv0CYsbNqK6JVrlGWlPDz7TBr2iY0BK79A9+tkycRG6 iKp87vgnnEhBEI1oDJOhcW8oyjGNbfIFNhACy1iSlUPKX9rNiq0L6+fLLKG8smd1405h /PKICL8PT0gts2EpOgFvsCg0T6EWLpccVHy0XMIhvTgZRNGAeqlT3S6s6IHotsGCt39d 71qA==
X-Gm-Message-State: AGRZ1gJ+Ery+8eTSnAf0vFrZpirbZLCf8dyM52mC09i0QuvuZnluPu7b AvSgE76sAAHrtnOLogTSnfw4w+qUQsUevIMDOo/ukg==
X-Google-Smtp-Source: AJdET5e3qvZ8b2xfA3BHRn7UvWg1y8dEaj2APer2Y79RvsB3j+VJy+P2wuNKin8GhZCwM5581lUVLFQmlpvN9Hek2N0=
X-Received: by 2002:a1f:8b48:: with SMTP id n69mr2496531vkd.12.1541458667637; Mon, 05 Nov 2018 14:57:47 -0800 (PST)
MIME-Version: 1.0
References: <185c8d1d-3971-ad09-eee0-a26bed446a96@alvestrand.no> <CALiegfmbghnBtDt=wfCAbOWi5SDFTi2qPgDOuXHRazKSvvCKNQ@mail.gmail.com> <CA+ag07YD3oSuL=R=h-28waha4b7xf7haU+-oWuNbzO_sBY4MQw@mail.gmail.com> <e567832e-1918-d51c-6f00-a732547c0a8e@alvestrand.no> <CA+ag07byo1vReeo2uMKxmF1tnzW+4CJSMPLaJO79H0s9j0PO0g@mail.gmail.com> <31fb92c1-2934-c33f-a3cf-552f027eacda@alvestrand.no> <bb7f863b-510c-f460-c9b0-843d500784b8@gmail.com> <5db76ada-b896-7eba-b42e-85b2e239dc42@alvestrand.no> <db90e287-145b-5ffe-18c0-f38faed76c07@gmail.com> <CALiegf=7yJJEbGT9SrbcEBBo9cnBbPimDP_oaTzJL63hrnXGoQ@mail.gmail.com> <CA+ag07ZuGYBhr=djPP=nLXLX96Yp2O4H8rJT2z8RVvNTiky2qw@mail.gmail.com> <CALiegfmOsLgeO-jkj20qKa0=w-xwHJdKD12Py_Dvades8Jjnrw@mail.gmail.com> <fe3e1b27-ba9f-4403-6835-8e7faebb4362@gmail.com> <CALiegf=o6z-HpU+Dr=KbJJss6pYenEnKo620gEyvkJ6PubvWRA@mail.gmail.com> <e2ba2ad8-a3eb-fa99-3a77-2ea7131237a8@alvestrand.no> <CALiegf=1gvE04pWL_aKiw9q=N7iF2Max17Hb+vhkd9On4dp7Kg@mail.gmail.com> <ffad83c9-f14b-4cdd-2d58-b0c56e547053@alvestrand.no>
In-Reply-To: <ffad83c9-f14b-4cdd-2d58-b0c56e547053@alvestrand.no>
From: Iñaki Baz Castillo <ibc@aliax.net>
Date: Mon, 05 Nov 2018 23:57:35 +0100
Message-ID: <CALiegfm0Az3ubKc_id2_YJdbRSXo2jPqsMT3YRBh9KXUPP=MFA@mail.gmail.com>
To: Harald Alvestrand <harald@alvestrand.no>
Cc: Sergio Garcia Murillo <sergio.garcia.murillo@gmail.com>, rtcweb@ietf.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Archived-At: <https://mailarchive.ietf.org/arch/msg/rtcweb/O9h2dk31z9G4czYHYYty-QiZSWY>
Subject: Re: [rtcweb] JSEP question: How to set up simulcast for server-originated calls?
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, 05 Nov 2018 22:57:51 -0000

On Mon, 5 Nov 2018 at 23:54, Harald Alvestrand <harald@alvestrand.no> wrote:
> If in your example, the writer of the SDP knew that the browser would
> discard encodings at the end, it would send
>
> - 150kbps
> - 400kbps
> - 1000kbps
> - 120kbps
> - 750kbps
>
> That's predictable.
>
> If it thought "biggest and smallest are most important", it could also
> choose to send
>
> - 120kbps
> - 1000kbps
> - 400kbps
> - 150kbps
> - 750kbps
>
> If it thought "most clients are 400kbps, or 1000kbps, the 120kbps client
> is only seen occasionally, and handles 3 streams anyway",
> it could send
>
> - 400kbps
> - 1000kbps
> - 120kbps
> - 150kbps
> - 750kbps
>
> If the behavior of the responder is predictable, the initiator can
> achieve the result it wants.

Right, my fault. In my mind bitrates had to be ordered.


-- 
Iñaki Baz Castillo
<ibc@aliax.net>

v2.23.0 | Report a Bug | By Email