Apple has prototyped all of the required attributes, operations, and values in the following prototype draft of IPP Shared Infrastructure Extensions:
http://ftp.pwg.org/pub/pwg/ipp/wd/wd-ippsix10-20140226-rev.pdf
Comments:
1. During implementation, it was difficult to make sure that I had implemented all of the required attributes. I ended up making a list of the required attributes, which should be included in the specification.
2. There is no way to provide resource files - icons, ICC profiles, etc. This could be done with a few new attributes provided by the Infrastructure Printer with support for the HTTP PUT and DELETE requests:
a. “printer-resource-directory-uri (uri)” - specifies a HTTP or HTTPS URI that can be used to upload resource files using PUT requests or delete resource files using DELETE requests
b. “printer-resource-k-octets-available (integer(0:MAX))” - specifies resource storage availability
c. “printer-resource-k-octets-used (integer(0:MAX))” - specifies kilobytes of resources that have been used
d. Issues:
i. HTTP authentication can limit to proxy user, but how to limit to output devices that have been registered?
ii. Also, for fan-out how to avoid/prevent name collisions? Provide separate “printer-resource-directory-uri” values, filtered on “output-device-uuid”?
3. There is no way to do registration, but our implementation works with a printer-uri that is obtained separately
a. Output Device is “registered” by using the Update-Output-Device-Attributes operation
4. There is no way to do de-registration
a. This is more of an issue for fan-out configurations - no way to remove an output device from the Infrastructure Printer
b. We ended up adding a Deregister-Output-Device operation corresponding to the existing Cloud Imaging Model DeregisterSystem operation
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Michael Sweet, Senior Printing System Engineer, PWG Chair