Re: [RE] Results of today's discussion
All,
Hmm...my search found a different affiliation. I guess
that is a problem when tentative numbers are used before
the PAR is actually approved.
Congestion management is more closely affiliated to RE, but
CM appears to be dealing more with dynamic load leveling,
to reduce losses due to excess transmission rates through
a congestion point.
The CM group has not, from my observations, dealt with
real-time delivery requirements. The CM work (or what I
have observed of it) is dealing primarily with reduced losses,
as opposed to the reduced latencies being addressed in RE.
Maybe in the future we should use numbers _and_ titles,
when phrasing questions. That would reduce the context ambiguity.
DVJ
-----Original Message-----
From: Shvodian William-r63101 [mailto:bill.shvodian@freescale.com]
Sent: Sunday, October 31, 2004 5:13 PM
To: IEEE 802.3 Residential Ethernet; David V James
Cc: STDS-802-3-RE@LISTSERV.IEEE.ORG
Subject: RE: [RE] Results of today's discussion
David and John, There is a draft PAR for 802.2ar "Congestion Management",
which is up for November approval along with 802.3as "Frame Extensions."
From 802.3ar:
4. TITLE OF DOCUMENT: Information technology -- Telecommunications and
information
exchange between systems -- Local and metropolitan area networks -- specific
requirements Part 3:
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access
Method and Physical
Layer Specifications Amendment: Enhancements for Congestion Management
13. SCOPE: To specify IEEE 802.3 MAC parameters and minimal augmentation of
MAC operation
and management parameters of IEEE Std 802.3 to provide rate control and
support of IEEE 802
congestion management.
Completion of this document contingent? No
14. PURPOSE: This project will enable accelerated deployment of Ethernet
into emerging limited topology applications that require improved delay,
delay variation and frame loss characteristics.
14a. Reason: Ethernet networks are being used in an increasing number of
application
spaces (clustering, backplanes, storage, data centers, etc.) that are
sensitive to frame delay, delay variation and loss. Study Group
presentations have shown that Ethernet networks can experience higher
throughput, lower delay, and lower frame loss by performing congestion
management. This will improve Ethernet in its growing number of
applications.
Bill
-----Original Message-----
From: owner-stds-802-3-re@IEEE.ORG [mailto:owner-stds-802-3-re@IEEE.ORG] On
Behalf Of John Grant
Sent: Sunday, October 31, 2004 6:42 AM
To: STDS-802-3-RE@LISTSERV.IEEE.ORG
Subject: Re: [RE] Results of today's discussion
At 15:57 30/10/2004 -0700, David V James wrote:
>Bill,
>
>>> 1) How would a PAR for this study group differ from 802.3ar?
>>> Would the 2 TGs be coordinated somehow?
>I gather you are referring to "Frame Extensions".
>I think RE is dealing mostly with the timely delivery of frames, while
>802.3ar Frame Extensions is dealing more with increases in frame
>lengths.
Looking at
http://www.ieee802.org/3/cm_study/public/september04/agenda_2_0904.pdf
(slides 24 onwards), there seems to be more overlap with the Congestion
Management SG. There doesn't seem to be a P802.3ar yet, though Frame
Extensions SG used that designator in some of their July material.
However, given that FE is considering adding about 500 extra bytes of
overhead (!), increasing total frame size by 30% (and potentially including
some fields that could be of use to RE), there ought to be some kind of
liaison process at the next stage.
John Grant
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