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Re: [RE] Technical Feasibility

You are not mistaken. CobraNet uses its own synchronization services as do most current media protocols.

 

One should consider whether you want synchronization to be part of the network. ATM's answer to this is no. 1394 says yes (and yet many of the media protocols used on 1394 re-implement synchronization).

 

-----Original Message-----
From: owner-stds-802-3-re@listserv.ieee.org [mailto:owner-stds-802-3-re@listserv.ieee.org] On Behalf Of Jim Battaglia
Sent: Tuesday, August 31, 2004 2:04 PM
To: STDS-802-3-RE@listserv.ieee.org
Subject: Re: [RE] Technical Feasibility

 

Okay, but I wasn't aware that the synchronization elements were part of the .3 open standard.  I had thought that those features were proprietary enhancements.  Am I mistaken?

-Jim

Gross, Kevin wrote:

Please elaborate on limitations. Our audio network (CobraNet) is .3 based
and absolutely supports synchronized playback.
 
-----Original Message-----
From: owner-stds-802-3-re@listserv.ieee.org
[mailto:owner-stds-802-3-re@listserv.ieee.org] On Behalf Of Jim Battaglia
Sent: Tuesday, August 31, 2004 1:08 PM
To: STDS-802-3-RE@listserv.ieee.org
Subject: Re: [RE] Technical Feasibility
 
Multi-node, synchronized playback is another important element of a a/v
friendly digital home network.  This is also a limitation of the current
802.3 spec.
 
-Jim Battaglia
Digital Entertainment Networking
Pioneer Research Center USA, Inc.
415-305-6263 (mobile)
 
John Gildred wrote:
 
  
One of the limitations in the current 802.3 specification is that there
is no way to say "I need 20Mbps for my application until I say stop or
timeout". This is absolutely necessary for AV across a point to point
link (and eventually over a bridge). Currently priorities allow you to
say "I need my application to be priority x" which may or may not be
higher than other applications. And if two applications choose to use
the same priority, then they will inevitably step on each other. Trying
to manage this at higher levels (higher than 802.3) is much more
difficult and expensive.
 
Deterministic latency is part of this requirement. This is not just a
problem over a bridge, as a point to point link has several
applications on each side competing for the pipe at a given moment.
 
-John Gildred
Vice President of Engineering
Pioneer Research Center USA
A Division of Pioneer Electronics
101 Metro Drive, Suite 264
San Jose, California 95110
john@pioneer-pra.com
(408) 437-1800 x105
(408) 437-1717 Fax
(510) 295-7770 Mobile