IPP Mail Archive: RE: IPP> IPP Implementation Questions

IPP Mail Archive: RE: IPP> IPP Implementation Questions

RE: IPP> IPP Implementation Questions

Manros, Carl-Uno B (cmanros@cp10.es.xerox.com)
Fri, 9 Jul 1999 23:04:43 -0700


Your question is absolutely correct for this DL, we want to learn about
problems and questions that implementers run into with IPP.

As for answer to your specific question, we did not make any firm rules on
this in the standard as this depends on the capacity of your printer or
print server and on any local policy that you want to apply.

One way of doing this is to always wait for the last document flag to be set
and don't start printing until you have the whole job. In this case you need
to have an internal time-out in the printer after which you automatically
cancel the job if you do not get the last document flag. This solution
requires that you have enough spooling space to actually store the whole job
before you start printing.

Another implementation choice would be to start printing the job right away
without waiting for the last document or the last document flag. If you have
more limited space to queue job data or if you expect to have jobs with many
documents, this may be your only choice. Again, you will need a time-out in
case you never receive the last document flag and you would need to abort
the job at some stage.

There might be other implementation choices or combinations of the two
described above.

Hopefully people who design IPP clients will make sure that if they support
the Create-Job and Send-Document operations, that the client software alerts
a user if there is no indication given about the last document.
The IPP client should probably be configured to not even send the Create-Job
operation until the user has given an indication about the last document.
This would make things work well at the IPP Printer end, but you could still
have network failures which prevent the last Send-Document operation to go


> -----Original Message-----
> From: Podojil, Jerry D. x119 [mailto:JPODOJIL@genicom.com]
> Sent: Friday, July 09, 1999 6:47 AM
> To: 'ipp@pwg.org'
> Subject: IPP> IPP Implementation Questions
> Hello - my name is Jerry Podojil (Genicom Corp.) and I am
> starting design
> work on an IPP server implementation (for a printer).
> I don't know if this is the appropriate place to send implementation
> questions - if not please let me know.
> Question:
> In the case where the server receives a Create Job followed
> by multiple Send
> Document requests - is the server guaranteed to receive a
> Send Document with
> the "last-document" flag set? Should the server wait for this
> "last-document" before starting to "process" the job? Should
> the server
> wait for this "last-document" before "completing" the job?