RE: iSCSI: draft 7: remove S bit and Status field from the Data-i

[Dave Sheehy <dbs@acropora.rose.agilent.com>]

David,

> I think you've taken a wrong turn.  

I think John hit the nail on the head.

> > Second, thoughts of removing the immediate data seem not to be
> > simplification, since all the information to tie the data to the command
> is
> > right there with the command.  That has got to be easier than matching up
> > separate PDUs of data with the appropriate commands.
> 
> Actually, that was the point, since the logic for "matching up separate
> PDUs of data with the appropriate commands" has to exist for inbound
> Data PDUs already.  

Except that there is a target context present in the solicited case to route 
the data. That doesn't exist in the unsolicited case.

> The slide I presented in London was about replacing
> immediate data with an unsolicited data PDU immediately following the
> command, thus removing the immediate data case in favor of reusing the
> logic for dealing with separate Data PDUs.  Remember that this was presented
> as a simplification possibility.

This does help some. It eliminates the situation where a target can receive
an essentially unlimited number of immediate data commands prior to receiving
*any* data PDUs.

But, do you mean to say that *one* unsolicited data PDU would follow the
command? Wouldn't that be unnecessarily restrictive if the PDU size is small?
Simply guaranteeing that the data PDUs will immediately follow the command
seems like an adequate improvement.

Dave Sheehy