Re: Question on the Maximum number of packets per second
Tim,
Before the St Louis clock vote, a "box vendor" could have the
system provide clocking for all of the PHYs, LAN and WAN, as well as the
rest of the system. In that case, no inter-clock-domain
compensation was required.
If the system clock is at +100PPM and the WIS is at +20PPM,
there are two separate, independent, clock domains now operating between
the MAC Client and the PHY. That will require some form of
compensation. The alternative is to require the "box
vendor" to have a +20PPM clock, which is now an
implementation specification issue.
Thank you,
Roy Bynum
At 04:02 PM 6/4/01 -0400, Tim Warland wrote:
Roy Bynum wrote:
> Tim,
>
> Where, in the resolution that was passed in St Louis, was
additional
> compensation added to the rate adaptation to compensate for a system
clock
> running at +100PPM and a transmitter with another clock operating
at
> +20PPM? That is a total compensation delta between the MAC
Client/RS and
> the WIS of 120PPM. From what I understand, the current rate
adaptation
> scheme was based on the system clock and the WIS clock being the
same.
Under the resolution from St. Louis, there was no added
compensation.
The system clock is still required to provide 10.000 Gb/s +/-
100ppm
while the transmit clock in WIS mode operates at 9.95328 Gb/s
+/-20ppm.
If anything the compensation is simplified since there is now a
narrow
range of frequency extremes within which to perform compensation.
--
Tim Warland P.Eng.
Hardware Design Engineer Broadband Products
High Performance Optical Component Solutions
Nortel
Networks
(613)765-6634