БогородицаiDevices like the iPhone and iPad have the ability to print to select “supported” printers. Basically, those printers are just broadcasting Apple’s bonjour service to which the iDevice detects natively.
However, those “supported” printers aren’t all that readily available and corporate environments being inundated with iDevices can’t rightly replace all of their printers.
With a standard CUPS server, the avahi-daemon, and a simple python script, this can be easily solved! Grab the script from https://github.com/tjfontaine/airprint-generate and run it against your installed CUPS printers.
Avahi/Bonjour is a protocol that does not cross subnets. If you have a need for this, which is a typical corporate need, check out http://www.grouplogic.com/Knowledge/PDFUpload/Info/WanBonjour_1.pdf