RE: Chapter 46: preamble length
There are a number of places within 802.3ae that synchronization between
clock domains may require some form of compensation. The WIS was just an
example of a part of the structure that may require clock compensation.
Generally, we permit shortening of the IPG and preamble to assist with this
compensation so that the data remains untouched.
I'm not sure if that's helping you understand it any better.
From: Sanjeev Mahalawat [mailto:email@example.com]
Sent: Wednesday, March 28, 2001 1:46 PM
To: Booth, Bradley; firstname.lastname@example.org
Subject: RE: Chapter 46: preamble length
At 10:08 AM 03/28/2001 -0800, Booth, Bradley wrote:
>In 10GbE, truncation of the preamble can occur due to
>the asynchronous timing associated with the WAN PHY.
PCS + PMA = LAN PHY
PCS + WIS + PMA = WAN PHY
The PCS and PMA processes are common in both LAN and WAN
The only difference is extra WIS. And all WIS is supposed to
take the MAC frame (Preamble + Data + IPG) and encapsulate
in STS-192c frame without any involvement, visibility into
the MAC framing
process. So, I am not getting where and why the WIS should
open the MAC
frames and try to change it. Could you please explain it a