RE: Towards Consensus on TCP Connections

["Douglas Otis" <dotis@sanlight.net>]

Peter,

iSCSI intertwines LUN states to save TCP overhead.  In doing so, one tag
error sorting millions of tags within the mid-stream point of aggregation
(the iSCSI design) necessitates a catastrophic system reset.  With FC over
IP, the end point handles errors in accordance to the FC protocol such as
FCP-2 with simple frame aligned objects.  I count an additional complex
state machine in the middle of the communication path for iSCSI in addition
to new adapters with complex (INSANE) state machines at the client.  A
switch or a router would be a far safer choice for aggregation.

Doug

> -----Original Message-----
> From: owner-ips@ece.cmu.edu [mailto:owner-ips@ece.cmu.edu]On Behalf Of
> Peter Johansson
> Sent: Tuesday, August 15, 2000 10:39 AM
> To: IP Storage
> Subject: RE: Towards Consensus on TCP Connections
>
>
> At 09:24 AM 8/15/00, Douglas Otis wrote:
>
> >For details on proposed Fibre-Channel over IP ...
>
> Doug, just sort me out on this. Are you suggesting SCSI over (FCP-2 over
> (FC over (IP over FC))) to reach the storage devices? Incidentally, by
> "SCSI" I mean the SCSI command set. Or did I get the nesting
> parentheses wrong?
>
> If I do misunderstand, would you please set me straight. I though
> iSCSI was
> focused on SCSI over (SAM-compliant transport over (IP over [insert your
> favorite medium here])). I count one less nesting level---which usually
> goes hand-in-hand with less encapsulation overhead.
>
>
> Regards,
>
> Peter Johansson
>
> Congruent Software, Inc.
> 98 Colorado Avenue
> Berkeley, CA  94707
>
> (510) 527-3926
> (510) 527-3856 FAX
>
> PJohansson@ACM.org
>