[cups.general] RAW queue en 9100 printing

[Dennis Leeuw]

On 02/28/2013 12:47 PM, Helge Blischke wrote:
> Dennis Leeuw wrote:
>
>> Hi all,
>>
>> For all our windows printer queues we used to use IPP to the printer and
>> a RAW queue on CUPS and that worked fine, till a couple of weeks ago we
>> received a Xerox WC7556 printer. After a lot of tweaking and testing I
>> found that the only solution to make it work is to use port 9100 + RAW
>> printing.
>>
>> When we use IPP and RAW and we send a job that has to print 2 copies,
>> only one is printed.
>> When we use 9100 and RAW then all works fine.
>>
>> That fact that we found a solution is great, but I also would like to
>> know why. Can someone explain to me what the difference is and how this
>> works? Or can someone point me to the direction how to find out what
>> goes on?
>>
>> We are using Windows XP, CUPS 1.4.3 on Ubuntu.
>>
>> Thanks in advance,
>>
>> Dennis Leeuw
> I guess the IPP issue is due to the fact that in this case IPP job
> attributes take precedence over the respective settings of the PostScript
> job itself (an issue I already detected some time ago when using the java
> based IPP implementation in Xerox DocuTech printers).
> CUPS inserts a copies value of 1 in the printing IPP requests (as this is
> the default) which corresponds to the command line options for the filters
> and backends.
> I then hacked the IPP backend (starting with 1.3.5) to discard the copies
> attribute from the IPP request unless explicitely specified, so that the
> copies spec in the PS job got activated again.
> If you are interested, I could send you this (brute force) hack which could
> easily adapted to the 1.4.3 backend, but you then need to get the cups 1.4.3
> sources, compile from the sources, and replace the original ipp backen.
>
> Helge
>

Thank you for your explantion this sounds exactly like what might be 
going on. For now the 9100 printing solution is workable.

I am going to put wireshark on the wire, to see if I can find the 
command where it says 1 copy instead of two. Sounds like another mistery 
solved.

Thanks,

Dennis