RE: Common Encapsulation: CRC at beginning of frame?

[Charles Monia <cmonia@NishanSystems.com>]

Hi Robert:

The CRC you refer to only covers the encapsulation header, not the FC Frame,
which is covered by its own, separately computed FC CRC. 

According to section 2.1 on pp 6::

"CRC (word 6): When the CRCV Flag bit is zero, the CRC field SHALL contain
zero. When the CRCV Flag bit is one, the CRC field SHALL contain a CRC for
words 0 to 5 of the FC Encapsulation Header computed using the polynomial,
initial value, and bit order defined for Fibre Channel[3]."

Charles

-----Original Message-----
From: Harmon, Robert [mailto:rharmon@entradanet.com]
Sent: Wednesday, June 13, 2001 2:20 PM
To: Ips (E-mail)
Subject: Common Encapsulation: CRC at beginning of frame?




Has there been any discussion of putting the 
common encapsulation CRC at the end of the frame 
rather than -near- the beginning? 
Its possible to do CRC in H/W but to put it at the 
beginning of the frame is 5 times harder than putting 
it at the end.