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

[Paul Koning <ni1d@arrl.net>]

I find it interesting that SAM-2 mentions CRN but doesn't seem to give
it any semantics, leaving it to one particular transport to choose
semantics that it likes.

If the semantics are transport-specific, then cross-transport bridges
will have to be prepared to do appropriate work to handle what each
side expects.

From what I can see, minimally iSCSI could omit the CRN entirely,
since it is not necessary in iSCSI.  It currently carries it without
specifying any use for it.  (I believe this is the point that Santosh
made.)  Perhaps the intent was for it to be carried to iSCSI/FC
bridges so those bridges can just pass it on, rather than having to
make one up locally?  If so, that seems innocuous, but would be worth
stating explicitly.

I'm puzzled about what else iSCSI could do.  We could invent semantics
for this currently-unneeded thing, but to what purpose?  As for
protocol specific LUN modepages, I thought that iSCSI doesn't have any
protocol specific modepages.  It seems a stretch to add a whole new
mechanism (modepages) to iSCSI solely in order to say something about
a field that iSCSI isn't even using.

    paul