We have a SAAS application where reporting and other print jobs are generated on our application servers and then sent to CUPS print queues. The queue prints to printers at the client sites via IP printing; so far everything works fine.
However, we have a new requirement with a new customer. They want a print job to print to the printer closest to the current workstation in use. These are a group of 8 shared workstations, each workstation has two printers near by: a laser printer and a thermal label printer. The printers are connected to the network and have their own IP address. They support IP printing.
Since a user comes in a just selects an open workstation. We can’t tie printers to users. How do we identify a workstation and map its nearby printers. It’s easy enough to once we id a workstation to make a database table that stored it nearby printers that we can query but how do we ID the workstation?
Cookie? What happens if they delete all the browser history? Other ideas?
How about using this technique to get the IP address of the client using JavaScript then sending it back to the server:
http://www.gnucitizen.org/projects/javascript-address-info/
You could then map IP to the port on the NAT and have a unique mapping. He actually describes a very similar problem to yours.