RE: [10GBASE-CX4] Round trip delay (latest CX4 WP)
Hi Howard,
I think that Chuck's point is directed at clause 44 , table 44-2 where it
still says "with 15m of cable". Also, thanks for correcting my 2m reference.
Dan
-----Original Message-----
From: Howard A. Baumer [mailto:hbaumer@broadcom.com]
Sent: Tuesday, March 04, 2003 8:40 AM
To: ddprocurve@antelecom.net
Cc: Chuck Harrison; DOVE,DANIEL J (HP-Roseville,ex1); 10GBASE-CX4
(E-mail)
Subject: Re: [10GBASE-CX4] Round trip delay (latest CX4 WP)
Chuck, Dan,
Working paper V3.1 section 54.4 has the following in paragraph 2:
"The sum of transmit and receive delay contributed by the 10GBASE-CX4 PMD
shall
be no more than 512 BT (including 1 meter of cable). "
The round trip delay is specified with 1m of cable.
Howard
ddprocurve@antelecom.net wrote:
> Hi Chuck,
>
> This was an editorial "whoops" from our last meeting. We discussed this
and
> decided to spec it with 2m of cable, but
> never made the change in the document.
>
> Dan
>
> >Hi, all,
> >
> >Here is an extract from an email of early January:
> >
> >---- begin included text ----
> ><CH>
> >I was wondering about the delay constraints on CX4 (clauses
> >44.3, 54.8) -- 512 BT round-trip.
> >
> >If the propagation velocity of the cable is between 0.6 and 0.8 c,
> >then I compute the one-way delay for 15m as 625 to 834 Bit Times,
> >round-trip is double that. Am I missing something?
> ></CH>
> >
> ><HAB>
> > The 512 BT came from the cut & paste of the similar section
> >in Clause
> >53. This number, at this time, is meant to solicit feedback for an
> >actual measured delay. I haven't done this in our lab yet so thanks
> >for
> >this first cut correction.
> ></HAB>
> >---- end included text ----
> >
> >Has anybody made a measurement, to update WP3p1 Table 44-2?
> >
> >Cheers,
> > Chuck Harrison
> > Far Field Associates, LLC
> >