[cups.development] IPP Everywhere on Linux

[Michael Sweet]

Franz,

On Jun 12, 2012, at 2:13 PM, "franz.pfoertsch.brose" <franz.pfoertsch at brose.com> wrote:
> Hello Michael,
> 
> I installed the new CUPS 1.6b1 and looked for the new features on this version.
> Could you please explain the new features and how to use it?

There are only a few user-visible features in 1.6, mainly in how 1.6 can now do bonjour discovery of printers on Linux. Most of the changes are "under the hood" with new APIs that need to be adopted by the desktop toolkits before they will provide user-visible benefits.

> I am looking for 'IPP Everywhere', but do not know how to deal with it ...
> How does the server discover the capabilities of printers without a ppds.

PPD files describe printers in terms of what a postscript interpreter supports. CUPS traditionally has used them to describe raster printers as well, but they still use postscript commands to set the raster options.

IPP describes printers using abstract attributes like "media" and "sides". The printer ultimately translates these to whatever internal commands are needed. IPP Everywhere just standardizes what operations, attributes, formats, and protocols are required, allowing any client to print without printer-specific software. One way to implement support for this is to create a ppd file for a discovered printer, and that is something you will see in add-on components for CUPS in the future.

> where are the tools to do a IPP-discover?

The dnssd backend does discovery of IPP printers.