RE: [SWMP] semantic layers

"Tony Parisi" <tparisi@mediamachines.com> Fri, 24 August 2007 17:58 UTC

Return-path: <swmp-bounces@ietf.org>
Received: from [127.0.0.1] (helo=stiedprmman1.va.neustar.com) by megatron.ietf.org with esmtp (Exim 4.43) id 1IOdQg-0004Km-W2; Fri, 24 Aug 2007 13:58:42 -0400
Received: from [10.91.34.44] (helo=ietf-mx.ietf.org) by megatron.ietf.org with esmtp (Exim 4.43) id 1IOdQf-0004Kb-32 for swmp@ietf.org; Fri, 24 Aug 2007 13:58:41 -0400
Received: from worlds.webers.org ([64.34.168.199] helo=william.mediamachines.com) by ietf-mx.ietf.org with esmtp (Exim 4.43) id 1IOdQd-0000Sy-L0 for swmp@ietf.org; Fri, 24 Aug 2007 13:58:41 -0400
Received: from NEO (h-66-134-93-202.snvacaid.covad.net [66.134.93.202]) by william.mediamachines.com (Postfix) with ESMTP id E7C99464005; Fri, 24 Aug 2007 12:56:25 -0500 (CDT)
From: "Tony Parisi" <tparisi@mediamachines.com>
To: "'Jay C. Weber'" <jweber@mediamachines.com>, <john_patterson@us.ibm.com>
Subject: RE: [SWMP] semantic layers
Date: Fri, 24 Aug 2007 10:58:24 -0700
MIME-Version: 1.0
X-Mailer: Microsoft Office Outlook, Build 11.0.6353
Thread-Index: AcfmZKQ+gXTWMGPeRSeQ0HqLnKLYrAAEnJDQ
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138
In-Reply-To: <46CEFBA9.60602@mediamachines.com>
Message-Id: <20070824175625.E7C99464005@william.mediamachines.com>
X-Spam-Score: 0.0 (/)
X-Scan-Signature: 93b4f10b2112e1468b61e19ea6180478
Cc: swmp@ietf.org
X-BeenThere: swmp@ietf.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussion of a Simple Wide-area Multiuser-3D Protocol <swmp.ietf.org>
List-Unsubscribe: <https://www1.ietf.org/mailman/listinfo/swmp>, <mailto:swmp-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www1.ietf.org/pipermail/swmp>
List-Post: <mailto:swmp@ietf.org>
List-Help: <mailto:swmp-request@ietf.org?subject=help>
List-Subscribe: <https://www1.ietf.org/mailman/listinfo/swmp>, <mailto:swmp-request@ietf.org?subject=subscribe>
Content-Type: multipart/mixed; boundary="===============1715492720=="
Errors-To: swmp-bounces@ietf.org

Jay

 

That's probably worth some clarifying language when we write the real SWMP
spec. Remember folks that all of this discussion is playing off of a short
white paper

 

Tony

 

 

  _____  

From: Jay C. Weber [mailto:jweber@mediamachines.com] 
Sent: Friday, August 24, 2007 8:39 AM
To: john_patterson@us.ibm.com
Cc: swmp@ietf.org
Subject: [SWMP] semantic layers

 

Jon: there are many issues in your note so I will respond in pieces, so we
can discuss issues separately and without undue reading burden on the others
:-)

john_patterson@us.ibm.com wrote: 

A)  As originally specified, swmp does not distinguish between requesting a
state change and being notified of a state change.  It tends to treat the
state sharing as largely a replication task with neither network element
having a controlling role over the state.  I think it is more realistic and
practical to assume that each network element has control over its state and
the other network element may request changes and be notified when changes
happen.

I agree that distinction is important.  The original SWMP doesn't take a
position on which elements have a controlling role, leaving that to the
semantics of the architecture.  My intent was to separate the two layers of
semantics, so that the protocol would be kept simple and be applicable to
many different architectures.

E.g., a peer-peer architecture would specify, as you say, that "each network
element has control over its state and the other network element may request
changes and be notified when changes happen", but some client-server
architectures (including most MMOGs) vest all control over state in the
server element.  That is, a state message from the server is always an
authoritative notification, and a state message from a client is always a
provisional request.  In such an architecture, network elements get this
semantics from their known roles, they don't need to get it from inside the
messages.

jay

-- 
Jay C. Weber, Ph.D. 
CTO, Media Machines Inc. 
650-279-2311 

_______________________________________________
SWMP mailing list
SWMP@ietf.org
https://www1.ietf.org/mailman/listinfo/swmp