Re: [rmcat] requirements (was Re: time to get active)

Fu Jiantao <fuji246@gmail.com> Tue, 05 March 2013 09:17 UTC

Return-Path: <fuji246@gmail.com>
X-Original-To: rmcat@ietfa.amsl.com
Delivered-To: rmcat@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8A4C321F887F for <rmcat@ietfa.amsl.com>; Tue, 5 Mar 2013 01:17:51 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.599
X-Spam-Level:
X-Spam-Status: No, score=-2.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, HTML_MESSAGE=0.001, NO_RELAYS=-0.001]
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 4zzCSKutG0HC for <rmcat@ietfa.amsl.com>; Tue, 5 Mar 2013 01:17:50 -0800 (PST)
Received: from mail-la0-x230.google.com (mail-la0-x230.google.com [IPv6:2a00:1450:4010:c03::230]) by ietfa.amsl.com (Postfix) with ESMTP id 3D03E21F8873 for <rmcat@ietf.org>; Tue, 5 Mar 2013 01:17:50 -0800 (PST)
Received: by mail-la0-f48.google.com with SMTP id fq13so5812099lab.7 for <rmcat@ietf.org>; Tue, 05 Mar 2013 01:17:49 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:x-received:in-reply-to:references:date:message-id :subject:from:to:content-type; bh=tQ1ojEFcg1za15EmfxEHeULzDRtAMy/nfoP/dpE+CP4=; b=cGYCUpd3uGIyWOic0iQGqvE5e2jpYHzYaUU04Yn/+TZA/qKTLcwwxiREtHQNhzyJUB l30qR0q+VJBvn8GQYz73vvBF1Li7UWM+skNREiOCZOTAA4fgQD+/tYSdN7W1hDTquwIP heE2mD1Rlov6wOzyz4phP9E95+vUraFd77m11OcCW7PAleJfOpzGklzJpEUlU7RBBX34 3oWwzHkYVXRAGhiOZLNd/YI3071QUEh4ND115tU6dSJSARpawxWRiadT7GgWVCAAjWWE la6FWLgfEGq5tXt8DlqRB5LL8FxDNWrv1GJu1BsEjW3stD67KLTwzKOWG9PQR2sBkssV CUrw==
MIME-Version: 1.0
X-Received: by 10.152.110.6 with SMTP id hw6mr20873907lab.43.1362475069172; Tue, 05 Mar 2013 01:17:49 -0800 (PST)
Received: by 10.114.25.231 with HTTP; Tue, 5 Mar 2013 01:17:49 -0800 (PST)
In-Reply-To: <023D88F2-1A6E-47C2-91B2-8B56DEEC70B1@g11.org.uk>
References: <D4D47BCFFE5A004F95D707546AC0D7E91F768E66@SACEXCMBX01-PRD.hq.netapp.com> <CAH56bmDCaQB3fQLq4UyiEWY2_qEhHXzp7aoyqde5K=rMZcLKvg@mail.gmail.com> <D4D47BCFFE5A004F95D707546AC0D7E91F7690F6@SACEXCMBX01-PRD.hq.netapp.com> <023D88F2-1A6E-47C2-91B2-8B56DEEC70B1@g11.org.uk>
Date: Tue, 05 Mar 2013 17:17:49 +0800
Message-ID: <CAKmxLjWpEfD+iHdnczMSEymyu-N4=3kegqUOQU0MUFbw61280A@mail.gmail.com>
From: Fu Jiantao <fuji246@gmail.com>
To: rmcat WG <rmcat@ietf.org>
Content-Type: multipart/alternative; boundary="bcaec54b48d083754e04d729f2c2"
Subject: Re: [rmcat] requirements (was Re: time to get active)
X-BeenThere: rmcat@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: "RTP Media Congestion Avoidance Techniques \(RMCAT\) Working Group discussion list." <rmcat.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/rmcat>, <mailto:rmcat-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/rmcat>
List-Post: <mailto:rmcat@ietf.org>
List-Help: <mailto:rmcat-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/rmcat>, <mailto:rmcat-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 05 Mar 2013 09:17:51 -0000

Another concern for the requirement

There maybe sometimes UDP is blocked, and ICE may use TCP connection(see
http://tools.ietf.org/html/rfc4571 for how to use rtp/rtcp on TCP), this is
a practical user scenario, is there any consideration for this case? I'm
not sure whether this is in the scope of rmcat.

Thanks!

Jeromy


2013/2/28 ken carlberg <carlberg@g11.org.uk>

> well, perhaps I can get the ball rolling in terms of a headache to chew on
> :-)
>
> The second requirement in draft-jesup-rmcat-reqs-01.txt is...
>
>   2.   The algorithm must be fair to other flows, both realtime flows
>         (such as other instances of itself), and TCP flows, both long-
>         lived and bursts such as the traffic generated by a typical web
>         browsing session.  Note that 'fair' is a rather hard-to-define
>         term.
>
>         A.  The algorithm must not overreact to short-term bursts (such
>             as web-browsing) which can quickly saturate a local-
>             bottleneck router or link, but also clear quickly, and
>             should recover quickly when the burst ends.
>
>         B.  We will need make some evaluation of fairness, but deciding
>             what is "fair" is a tough question and likely to be
>             partially subjective, but we should specify some of the
>             inputs needed in order to select among algorithms and
>             tunings presented as options.
>
> however, the document does not have a definition of the term "fair" or
> "fairness".  And while the document points us to terminology in another
> draft (draft-ietf-rtcweb-overview-06.txt), this other draft doesn't even
> mention "fair" or fairness".  I think one nit is that the RMCAT
> requirements draft needs its own terminology section instead of pointing to
> another draft.
>
> And more importantly, I think we need to bite the bullet and decide what
> is "fair" / "fairness".  It just doesn't seem possible for us to say that
> the algorithms *must* be fair, but then punt in defining what is (or
> perhaps, what is not) fair.  And I'm definitely not meaning to beat up on
> the author, but rather ourselves.
>
> As a starting point, and in the context of real time apps, I don't think
> we need to be fair to a continual series of parallel short transaction
> flows.  Rather, I would prefer to be fair, or focus our attention, to
> longer transaction flows.
>
> thoughts?  Have I missed something?
>
> -ken
>
>
>
> On Feb 27, 2013, at 1:37 PM, "Eggert, Lars" <lars@netapp.com> wrote:
>
> > On Feb 27, 2013, at 19:35, Matt Mathis <mattmathis@google.com> wrote:
> >> Did we perhaps address all of the hard problems in the charter process,
> so
> >> now there is nothing to controversial to chew on?
> >
> > I wish...
> >
> > Lars
>
>