Conformance of printers' IPP implementations

[John A. Murdie]

Back in August, I tried printing to an HP LaserJet 8150DTN printer using CUPS 1.1.23's ipp backend (with my own bug fix for STR #1251), and found that even with the latest HP firmware (still the latest - MB7.119) these printers didn't return either a value for job-media-sheets-completed or job-media-pages-completed, because the implementation of those request attributes is not mandatory. Michael (Sweet) told me that there was another known issue with the HP IPP implementation which is that "HP doesn't support chunking (a required feature)" - see cups.development article #714 - 16:28 August 19 called "Re: Conformance of HP's IPP implementation". (Try Googling for "ipp chunking" for an explanation - though I can't say I fully understand this matter yet!)

Why don't HP provide a correct and complete IPP implementation in all their printers? Is it just the HP LaserJet 8150 series that does not? How can I or we persuaude HP to provide a full 8150 IPP implementation?

If I'm forced to abandon HP printers after all, is there somewhere I can find information about the conformance of various manufacturers' implementations of IPP to the standard - and checklists showing which non-mandatory IPP features are implemented by each make and model of printer? Perhaps there should be (say) a `www.ipp.org' (that web address is actually used by the Illinois Prairie Path organisation!) to which we could all contribute our findings about the IPP conformance of our printers?

John A. Murdie
Department of Computer Science
University of York
UK