iFCP CRC

[Wayland Jeong <wayland@troikanetworks.com>]

Josh,

Charles mentioned in his presentation that a CRC was being added to the
encapsulation scheme.
I'm wondering if you could elaborate on the motivations for this move.
Certainly, It would be very
desirable to protect the iFCP encapsulation header, but adding another CRC
could be costly
for hardware. I know that "implementations" may be able to ensure that FC
traffic is entirely
encapsulated within a single network MTU, but generally speaking, that might
not be the case.
Requiring yet another CRC which is hard to manage across network packets
seems like overkill.

Fibre Channel and iSCSI both have considerations for CRC. I know that iFCP
mucks with the
encapsulated payload (D_ID's and S_ID's), but it seems like it would be
completely acceptable
to check and re-calculate the FC CRC to cover the modifications to the
payload of the iFCP PDU
(you have to do this anyway). To protect the iFCP header, I would vote for a
simple checksum which
just covers the header. 

-Wayland