IPP Mail Archive: Re: IPP> MOD - simplified legal state transition diagram

Re: IPP> MOD - simplified legal state transition diagram

Bill Wagner (bwagner@digprod.com)
Wed, 21 May 1997 17:02:30 -0400

I apologize if I missed a step or two in this exchange. Of course, I agree
with the objective and believe the states listed are adequate. However, the
'unknown' state, within general MIB use at least, has been more a
reflection on the state of the equipment than the job. That is, the state
of a job is unknown because of some sensing difficulty or sequence
difficulty with the equipment, not because it is a normal state in the
sequence of handling a job.

It would be quite possible for a unit to report no state other than
unknown. It seems it would also be possible for a unit to recognize a state
after it has previously been unknown. For example, if a job can be
identified, it can be canceled and the state is then likely to be canceled
and not unknown. In short, I suggest that unknown is a wild card rather
than a job state that exists before pending and processing and after
canceled and completed.

If something is necessary for the pre-pending and post complete states,
what about Other?

Bill Wagner, Osicom/DPI

______________________________ Reply Separator _________________________________
Subject: IPP> MOD - simplified legal state transition diagram
Author: Tom Hastings <hastings@cp10.es.xerox.com> at Internet
Date: 5/21/97 7:29 AM

So the simplified legal state transition diagram for IPP and JMP would become,
following Bob's proposal:

New state
Old state unknown(2) pending(3) processing(4) canceled(5) completed(6)
unknown(2) yes yes
pending(3) yes yes
processing(4) yes yes yes
canceled(5) yes
completed(6) yes

A blank entry indicates impossible transitions. Self loops are not
indicated, such as a Get-Attributes operation on a job, since they aren't
a job state transition.

For IPP we need to consider which job states and job state transtions are
required for conformance and which are optional.

JMP requires that processing(4), canceled(5), and completed(6) are
mandatory, so that pending(3) is optional. What about unknown(2)?
The former needsAttention state was also mandatory, so that the
new job-state reason: printer-stopped, should become a mandator job state
reason, correct?

For IPP and JMP, all transitions into the canceled state should be required.
However, the transition from processing back to pending (a job-held situation)
is optional.