Re: iSCSI: Some proposed vendor-specific (X-) keys

[Paul Koning <ni1d@arrl.net>]

Excerpt of message (sent 7 June 2002) by Luben Tuikov:
> Bill Studenmund wrote:
> > 
> > 
> > That comment reflects a very nice ideal. My concern is that I'm not sure
> > we're there. What about Luben's comments that there are existing
> > interoperability problems among compliant systems? AS I understand him,
> > compliant *iSCSI* systems. ??
> 
> I haven't checked for those lately, (especially in the login procedure),
> but any time you see ``MAY'' or ``may'' in the draft and a target
> and initiator arrive at different outcomes _just_ by taking one
> or the other route, you have ``compliant-non-interoperability''
> (as you coined the term).

That is not true at all.  "MAY" is fine if either choice results in
behavior that is acceptable to the other side.  In fact, that's the
only place where a standard is allowed to use it.  Sometimes,
achieving that requires that side A communicates its choice to side B;
in other cases it doesn't.

A very simple example is the use of MAY in the rules for responding to
protocol violations.  Since those cases don't occur in the first place
in conforming implementations, neither choice can possible result in
compliant non-interoperability.

If the spec allows a choice -- either with MAY or with MUST -- but the
conforming other end will for one of those two choices -- then the
spec is broken, pure and simple.

	paul