RE: FC/IP vs. iSCSI

["Ericson, George" <gericson@clariion.com>]

Costa,

Not arguing for or against iSCSI.  However, I don't agree with two of your
points on FC.  

FC ports are identified by both a 64 bit port-WWN and a 64 bit node-WWN.
Together, they form a 128 bit WWN that should scale to the internet.
(Note, that these addresses do not provide any routing hints.  But that's a
different kettle of fish.)

Secure Login is not an FCP layer problem.  My opinion is that the trust
relationship must be established end-to-end. For SCSI, this means between a
SCSI Application Client and a SCSI Logical Unit.  There is ongoing work in
this area within T10 that should be relevant to the iSCSI effort.
Note that a trust relationship can also be established at the FC-2 level.
However, the usefulness is more limited at that level.

Regards,
George Ericson 
EMC Corporation < http://www.emc.com/>
CLARiiON Advanced Technology
4 Coslin Drive, MS C44, Southboro, MA 01772
Office: (508) 480-7349; Mobile: (508) 498-8461; Fax: (508) 480-7913






-----Original Message-----
From: csapuntz@cisco.com [mailto:csapuntz@cisco.com]
Sent: Wednesday, August 16, 2000 5:56 PM
To: ips@ece.cmu.edu
Cc: csapuntz@cisco.com
Subject: FC/IP vs. iSCSI



FC/IP is NOT an alternative to iSCSI for most applications.

Unfortunately, making a protocol that works well in complex networks
is not as simple as just putting stuff into IP packets. IP packet
headers are not magical pixie dust that suddenly make higher-layer
protocol issues go away.

The FibreChannel stack today has the following deficiencies which do
not disappear when tunneling over IP:
	- FCP has no congestion control
	- FCP deals poorly with packet loss
	- Target naming is done with either 24-bit port IDs or 64-bit WWNs,
	   neither of which scale to Internet size
	- No secure login

Of course, you could address all the deficiencies by fixing FCP. But
by the time you do that, I maintain you will most likely end up with
something in the same order of complexity as iSCSI/TCP/IP.

-Costa