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Re: [8023-POEP] System Architecture



Hi David,

I agree with your observation from the RJ45 connector point of view.
It is actually a basic rule that we are using in the standard i.e. to
define a port not a system.

In short you are saying that:
1. A single PD in a PoE system can get power from each 2P
simultaneously.
2. It is possible that a PD system will get power from N x Ports=RJ45 by
utilizing a PD system that is constructed fron N PDs.
3. item 2 is out of scope of the standard due to the fact that the
standard define what happen in a single port.

I'll revise the presentation accordingly.

Thanks

Yair

 

  

-----Original Message-----
From: owner-stds-802-3-poep@xxxxxxxx
[mailto:owner-stds-802-3-poep@xxxxxxxx] On Behalf Of David Law
Sent: Wednesday, June 14, 2006 2:17 PM
To: STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-POEP] System Architecture

Hi Yair,

I'm not sure about this idea of N x 2P. The case of 2 x 2P PDs behind a 
single RJ45 (or 8 pin connector to use the term used in your slides) is 
certainly a special case we need to look at. But since the RJ45 has only

8-pins you cannot provide any more than 2 x 2P PDs behind a single RJ45.

Anything from 3 x 2P upwards requires multiple RJ45s.

However I would not classify the case of a system with multiple RJ45s
that 
chooses to implement PDs behind N of these connectors as a case of N x
2P. 
This is simply a case of multiple PDs that happen to be located within
the 
same system. The fact that these multiple PDs happen to be located in
the 
same system should have no impact on the specification. I would go as
far 
as to suggest that such system (however system can be defined - within 
same box/chassis/packaging) specifications, certainly in respect to 
Detection and Classification, are beyond the scope of the project.

There are products that ship today that provide two RJ45 and implement
two 
PDs behind them to provide redundancy. I believe these are compliant
with 
Clause 33 of IEEE Std 802.3-2005 and certainly would not agree with 
retrospectively imposing requirements on these.

Regards,
  David


owner-stds-802-3-poep@xxxxxxxx wrote on 14/06/2006 00:14:40:

> Hi all,

> Please find my action item for tomorrow's meeting.
> It is revised presentation from May meeting that focus on the concept
> 4P=2x2P and the more general case of N Pairs = Nx2P..
> Please feel free to comment.

> Thanks
> <<Flexible PD implementation driven Architecture 002.pdf>>
> Yair

> Darshan Yair
> Chief  Engineer
> PowerDsine Ltd.  -  The Power over Ethernet Pioneers
> 1 Hanagar St., P.O. Box 7220
> Neve Ne'eman Industrial Zone
> Hod Hasharon 45421, Israel
> Tel:  +972-9-775-5100, Cell: +972-54-4893019
> Fax: +972-9-775-5111

> E-mail: <mailto:yaird@xxxxxxxxxxxxxx
> <BLOCKED::blocked::BLOCKED::mailto:yaird@xxxxxxxxxxxxxx> >.
> <http://www.powerdsine.com
> <BLOCKED::blocked::BLOCKED::http://www.powerdsine.com/> >

> 
> [attachment "C.htm" deleted by David Law/GB/3Com] 
> [attachment "Flexible PD implementation driven Architecture 002.pdf"
> deleted by David Law/GB/3Com]