Re: [vwrap] Statements of Consensus. Flexibity First.

Boroondas Gupte <sllists@boroon.dasgupta.ch> Wed, 30 March 2011 11:28 UTC

Return-Path: <sllists@boroon.dasgupta.ch>
X-Original-To: vwrap@core3.amsl.com
Delivered-To: vwrap@core3.amsl.com
Received: from localhost (localhost [127.0.0.1]) by core3.amsl.com (Postfix) with ESMTP id B3EA128C0DB for <vwrap@core3.amsl.com>; Wed, 30 Mar 2011 04:28:27 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.988
X-Spam-Level:
X-Spam-Status: No, score=-1.988 tagged_above=-999 required=5 tests=[AWL=0.000, BAYES_00=-2.599, HELO_MISMATCH_NET=0.611]
Received: from mail.ietf.org ([64.170.98.32]) by localhost (core3.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id bOfij--dApgB for <vwrap@core3.amsl.com>; Wed, 30 Mar 2011 04:28:27 -0700 (PDT)
Received: from datendelphin.net (india288.server4you.de [85.25.150.202]) by core3.amsl.com (Postfix) with ESMTP id AA12F28C159 for <vwrap@ietf.org>; Wed, 30 Mar 2011 04:28:18 -0700 (PDT)
Received: from [192.168.1.101] (adsl-62-167-25-70.adslplus.ch [62.167.25.70]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by datendelphin.net (Postfix) with ESMTPSA id 439AD2E047 for <vwrap@ietf.org>; Wed, 30 Mar 2011 13:32:44 +0200 (CEST)
Message-ID: <4D931434.2030206@boroon.dasgupta.ch>
Date: Wed, 30 Mar 2011 13:29:56 +0200
From: Boroondas Gupte <sllists@boroon.dasgupta.ch>
User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110313 Lightning/1.0b3pre Thunderbird/3.1.9
MIME-Version: 1.0
To: vwrap@ietf.org
References: <20110330011458.GB8908@alinoe.com>
In-Reply-To: <20110330011458.GB8908@alinoe.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Subject: Re: [vwrap] Statements of Consensus. Flexibity First.
X-BeenThere: vwrap@ietf.org
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: Virtual World Region Agent Protocol - IETF working group <vwrap.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/listinfo/vwrap>, <mailto:vwrap-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/vwrap>
List-Post: <mailto:vwrap@ietf.org>
List-Help: <mailto:vwrap-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/vwrap>, <mailto:vwrap-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 30 Mar 2011 11:28:27 -0000

On 03/30/2011 03:14 AM, Carlo Wood wrote:
> Perhaps we should also start a wiki page (it's nice
> to have a stable url that one can refer to, which still
> is editable; that give me at least a feeling of progress),
> about statements that we reached consensus over.
Good idea.

> Being an abstract thinker and analyst, I believe we
> can tackle many of the current discussions at a much
> higer abstraction level first, making it easier, or
> even possible, to deal with the more detailed points
> of discussion.
We'll probably have to switch back and forth between levels of
abstraction during the discussion. A pure top-down design often won't
work. But I feel it's indeed reasonable to start at a higher abstraction
and see where we can go from there.

> I'd like to start with one such statement and ask
> for consensus on it (and if not, give your rationale
> why not).
>
>
> * Whenever a change X in the protocol is proposed
>   (which might be an addition, a change of existing
>   protocol or even deletion: any change, making
>   the protocol (VWRAP) go from A --> B), then that
>   change is accepted as part of VWRAP provided that:
Formulated like this, it sounds like the following requirements together
would be sufficient for acceptance. I guess you rather wanted to express
that they should be necessary for acceptance, but might not be
sufficient (further requirements might apply).

>   1) Protocol B can do everything that A could do.
>   2) No substantial extra demands are being made on
>      an implementation that only implements the
>      functionality of A.
As necessary but not sufficient acceptance requirements, I can consent
to these. I cannot consent to them as sufficient acceptance requirements.

> In other words: we choose for flexibility.
Or more specifically, total backwards compatibility between versions of
VWRAP. However, to make it easy (or at least easier/possible) to design
changes X or new versions B, such that they fulfill these backwards
compatibility requirements, we should already design previous versions A
for "forward compatibility".

If I remember correctly, you have made suggestions in past messages on
how to achieve such forward compatibility (e.g. protocol versioning
combined with protocol negotiation).

> Under no circumstances we want the *protocol* itself
> to be a limitation in what is possible, when that
> extra flexibility/possibility doesn't cost much for
> those not needing or using it.
Agreed.

Cheers,
Boroondas