Printing from cupsd to cupsd via an internet link: Where the filters are applied

[Sebastian James]

Hi CUPSers,

We've been using cups to print across a WAN link for quite a while now. It works well.

cupsd_1 receives a print job, then sends it using the https method over the WAN to cupsd_2 which then forwards it on to a printer.

If the incoming print job needs to be converted using the CUPS filtering system into a suitable format for the printer at the end of the chain, then the filtering HAS to happen at cupsd_1, as far as I can tell.

This is not always a good thing, because we generally end up transferring _more_ data across the link. For example, if the incoming job is a PDF file, then converting it into postscript suitable for an HP Laserjet printer leads to a _lot more_ data to transfer.

It seems that the ipp protocol or at least cups' implementation of it means that data that is sent via ipp or its encrypted version, https is considered "finished".

It would be great if it were possible to set a parameter in cupsd.conf to say "always apply file-typing heuristics and CUPS filtering to incoming jobs".

Would this feature be a major problem? I would like to implement it.

very best regards,

Seb James