PWG April 2019 Face-to-Face Meeting - Summary
April 26, 2019

The PWG held its April 2019 Face-to-Face Meeting on April 16-18, 2019 at Lexmark's headquarters in Lexington, Kentucky. This event was held in collaboration with Linux Foundation OpenPrinting Workgroup. Sessions were presented by both organizations over the event's 3 days. Representatives from Apple, Artifex, Canon, Google, High North, HP Inc., Lexmark, Kyocera, Mopria, Qualcomm, Red Hat, Ricoh, TIC, TCS and Xerox attended the meetings. Attendees reviewed work in progress including drafts of a number of in-progress specifications and papers, discussed proposals for new work, and discussed liaisons with partner groups. Here is a summary of the proceedings.

PWG Plenary

In the PWG Plenary, we reviewed the overall state of the PWG, its programs and initiatives, and briefly discussed upcoming face-to-face meeting scheduling. We noted that there are now 365 printers certified by the PWG's IPP Everywhereâ„¢ Self Certification program, with more certifications believed to be in progress. Leaders of the two active PWG workgroups (IDS Work Group and IPP Work Group) summarized their current status. Finally, we reviewed the status of our partners' work in Trusted Computing Group (TCG), IETF, Mopria Alliance, Linux Foundation OpenPrinting Workgroup, and a quick summary of our 3D liaisons.

Complete minutes are available here:

Linux Foundation OpenPrinting Workgroup

In the Linux Foundation OpenPrinting Workgroup sessions on the first day, Ira McDonald reviewed the Linux OpenPrinting project's accomplishments from 2018 and surveyed the efforts under way for 2019. Work included completing the work to move the filters to QPDF or MuPDF from Poppler, and a focus on reliability and bug fixes. Preparations continue for the shift from CUPS 2.2.x to 2.3, and full support for the soon-to-be-ratified IPP System Service. Ira also announced the adoption of a new logo and website for Linux OpenPrinting.

Mike Sweet presented the CUPS Plenary, reviewing the status of CUPS 2.2.x and the development status of CUPS 2.3, including a more detailed discussion of the CUPS 2.3 changes and enhancements. He also spent some time reviewing the significant deprecated feature sets from legacy CUPS releases to help developers understand why they are deprecated and the importance of moving to the new APIs. He finished with a discussion of CUPS Future features.

After lunch, Aveek Basu presented a review of the Linux OpenPrinting Workgroup's projects that are active in 2019. He discussed the upcoming "Google Summer of Code 2019" projects that will implement a generic framework for converting legacy drivers into CUPS Printer Applications, and test suites for IPP System Service, IPP Job Extensions 1.1, IPP Document Object 1.1, and IPP 3D Printing Extensions 1.1. He also covered the Linux OpenPrinting Workgroup's engagement in "Google Season of Docs", "Google Code In", and "Linux Plumbers Conference".

Sean Kau presented "Printing in Chrome OS", covering system details that differ from other operating system environments and how that affects printing support. He discussed some of the security features of Chrome OS and the work done to build releases for the various hardware platforms that run Chrome OS. Many of the software components developed by the Linux Foundation OpenPrinting Workgroup, as well as an unmodified CUPS release, are deployed as the core components of the Chrome OS print system. IPP Everywhere is supported out-of-box and helps to enable universal printing.

After a break, Till Kamppeter presented a detailed survey of completed, in-process and future work in the "cups-filters" and "ippusbxd" projects. Many bug fixes were made in 2018, and work continues on both of these projects. To close out the day, Michael Vrhel took us through a review of the status of Ghostscript, MuPDF and associated projects such as MuJS and MuPDF WebAssembly. Color space handling for unconventional color spaces was discussed, as well as code security and analysis.

Minutes were not taken, but all slides presented are available on the April 2019 F2F Event Page.

Internet Printing Protocol (IPP) Workgroup

The second day of the F2F event was dominated by IPP Workgroup sessions covering the majority of the Workgroup's wide range of engagement topics. Ira McDonald and Mike Sweet kicked it off by summarizing the status of current IPP Workgroup activities. We then moved to 3D Printing, considering the value and work required for the PWG to develop a an IPP 3D GUI client prototype. Paul Tykodi guided us through a discussion of work ISO JTC1 WG12, SME, AMSE, and related standards work outside the PWG to which Paul has been liaising and evangelizing PWG IPP 3D related semantics and technologies. There is growing interest in the work we did earlier with IPP 3D Printing Extensions. Characterizing materials and new 3D printing technologies may be needed in the future, but the consensus is that we are prepared for that work with the foundation we have laid with IPP 3D Printing Extensions v1.1, PWG Safe G-Code, and IPP Everywhere.

After a break, Mike and Ira covered the status of IPP System Service. Mike is close to completing prototyping work using ippserver, and showed a demo. Sean noted that the non-standard IPP attributes specific to the ippserver's implementation are non-standard, by renaming them to use the "smi2699-" prefix. We talked about the "Printer template" resource that could be used in a Create-Printer operation, which could make it very easy to create a new printer. We think Q2 is still a good target for getting to a stable draft, with specification finalization targeting late Q3 / early Q4 2019.

During lunch, Rick Yardumian presented a slide deck contributed by Canon. The slide set described a collection of various features Canon would like supported in IPP if they are not supported already. The group discussed each feature, some of which seemed to be supportable with IPP today, while others might need some additional specification work.

After lunch, we discussed the state of IPP Everywhere v1.1, and Mike demonstrated a new tool to convert the self certification report to a JSON format, that is intended to be used with the revised submission process. We discussed the requirements for print servers compared to physical printers, and also discussed relaxing the DNS-SD requirements for enterprise-class MFDs.

After a break, we reviewed the latest draft of IPP Enterprise Printing Extensions v1.0. We considered the semantics of feature terminology introduced by that draft and how it overlapped with JPS2 (PWG 5100.11). Job state phases and states were discussed, which are very important to the semantics of the new Proof Job and Stored Job feature concepts. We cut the review of this short to move on to IPP Job Extensions v2.0.

In the Job Extensions v2.0 review, we engaged on the fate of the much-discussed "document-format-details". A vigorous and productive discussion reviewing the merits and demerits of that attribute and its members, as well as the value that some of its members provided, produced a consensus for deprecating the attribute and some of its members while obsoleting other members. This led into the Job Accounting BoF, where we had a more open-ended discussion of use cases and requirements for job accounting generally. This will help to inform the IPP Workgroup in creating a sound functional replacement for "document-format-details" and other attributes used for Job Accounting. We plan to have another Job Accounting BoF at the August F2F.

On the third day, Mike led a review of the latest draft of IPP Encrypted Jobs and Documents. We considered use cases for the ownership of encryption keys, which might come from the Printer, but might also come from the User / Client. The group consensus was that this document should become a Standards Track specification, not a registration, because of its scope and uniqueness. Notifications for future drafts will be posted to both the IPP Workgroup and the IDS Workgroup, to encourage the IDS members to provide feedback from their own security-focused perspectives. We concluded our IPP sessions with next steps for the IPP Workgroup.

Complete minutes are available here:

Imaging Device Security (IDS) Workgroup

On the third day, Alan Sukert led the IDS Workgroup session with a review of state of the final draft of the Hardcopy Device (HCD) Protection Profile (PP) v1.1 proposed at the Hardcopy Device Technical Community (HCD-TC) face-to-face meeting held in Rome two weeks earlier. The NIAP TLS Package v1.1 was discussed for its candidacy as a possible addition to the HCD PP. Also, the latest HCD iTC Terms of Reference (ToR) and Essential Security Requirements (ESR) drafts were reviewed, which are the documents required by the process to create an HCD international Technical Committee (iTC). We then discussed thoughts on issues the HCD TC needed to address to transition from an HCD TC to an HCD iTC, and some thoughts on what requirements should be included in the eventual HCD collaborative PP (cPP). Finally, Ira provided an overview of the PWG Hardcopy Device Security Guidelines he is developing.

Complete minutes are available here:

Next PWG Face-to-Face Meeting

The next PWG Face-to-Face meeting will be a virtual event tentatively planned for August 28-29. Please check the PWG Meetings page for updates on plans for upcoming meetings.