RE: iscsi: CRN support not required. [was :Re: [Fwd: iSCSI: items discussed at WG meeting]]

[Paul Koning <ni1d@arrl.net>]

Excerpt of message (sent 2 April 2002) by Robert Grant:
> ...
> If you accept that making FC and iSCSI work well is not just the work of the
> fabric devices (dare I call them "boxes in the middle"?) then where is the
> best place to deal with the CRN mode pages? Does having the bridge deal with
> this make sense? It strikes me that CRN is a function between the initiator
> and target and as such is best left (as near as can be obtained) as
> negotiated between the two. So Dave's suggestion of iSCSI mode pages makes
> the most sense to me.

For something to be "end to end" it has to be transport-independent.
Conversely, if something is transport-dependent, it cannot possibly be
end to end when you have mixed transports and bridges.

It seems to me the problem is that CRN is clearly defined as transport
dependent, but in spite of that people are trying to assign end to end
semantics to it across transport converting bridges.  This is an
effort akin to squaring the circle.  

I don't see that hypothetical iSCSI modepages have anything to offer
to solve this problem.  Until and unless T10 decides to make CRN a
transport INdependent thing with consistenly defined semantics across
all transports, it is inescapable that bridges have to get directly
involved -- and CRN will not be end to end.

	 paul