Re: iSCSI: Require iSCSI to use packet formats similar to FC, etc ??

[Stephen Bailey <steph@cs.uchicago.edu>]

> SST and FCP are very dissimilar

Actually, SST and FCP are deliberately virtually identical.  The SST
status PDU is identical to FCP's.  The SST command PDU is FCP's with
the transfer length removed (it's already in another piece of the ST
PDU which carries the SST command PDU).

I did that so that I wouldn't get trapped in arguments about how this,
that, or the other SAM feature is offered by SST.  I could just say,
whatever FCP does, SST does, in basically the same way.

However, with all the clout iSCSI has, I'm sure we won't have any
trouble convincing anybody that not only does iSCSI do everything the
other widely deployed network SCSI does, we fix all their bugs, and do
twice as much beyond that, too :^)

The most important thing is having a simple, one-to-one correspondence
between components of iSCSI and FCP.  The PDU layouts don't have to be
identical, but that is one way to inarguably achieve the
correspondence.  I don't see any reason why the iSCSI/FCP
correspondence shouldn't be very close.  Put another way, if the
correspondence is WORSE (more algorithmically difficult to make) than
FCP/||SCSI (which is a somewhat poor but well known correspondence)
we've totally blown it.

Steph