[cups.bugs] [LOW] STR #2424: cups doesn't provide enough support for remote LPD queues

Michael Sweet mike at easysw.com
Tue Jun 26 08:21:06 PDT 2007

Dominik 'Rathann' Mierzejewski wrote:
> On Tue, Jun 26, 2007 at 10:12:58AM -0400, Michael Sweet wrote:
>> Dominik 'Rathann' Mierzejewski wrote:
>>> On Tue, Jun 26, 2007 at 08:03:07AM -0400, Michael Sweet wrote:
>>>> [STR Closed w/o Resolution]
>>>> Since the LPD protocol does not provide a way to track print jobs 
>>>> reliably,
>>>> there is no way for us to fix this issue. If you need reliable remote
>>>> printing, you must use IPP...
>>> LPRng can do it just fine using LPD. Why can't CUPS?
>> Because LPRng uses the LPD protocol natively, you are seeing the
>> remote queue and not a locally-managed queue like CUPS uses.
> So what's the problem with implementing this in CUPS? Or should
> I move this discussion to cups development/general list?

We will never support this sort of functionality in CUPS, because
a) we'd have to implement LPD support in all of the client apps and
b) it would expose one of the major problems with LPRng and LPD - if
the server goes down or changes, you lose your jobs because the
client doesn't have a local copy.

Unfortunately, since the status output from a LPD server is plain
text and the format is not well-defined, it is impossible to
reliably implement a "wait" mode in the backend itself.  We'd have
to make too many assumptions and alter the title or username we
send to the remote server to have something we can track, and even
then it might not work.

In short, if you want the functionality of LPD, stick with LPRng.
If you want the functionality of CUPS, stick with CUPS or IPP - LPRng
does provide limited support for it...

Michael Sweet, Easy Software Products           mike at easysw dot com
Internet Printing and Document Software          http://www.easysw.com

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