The print sub-system uses BSD print protocol and raw TCP to communicate with the printer. The printer vendor documentation will provide the information about which protocol to use. In general, we have found that the TCP protocol is more generic across printers.
The command to select the protocol is:
lpadmin -p printer_name -o protocol=bsd
or
lpadmin -p printer_name -o protocol=tcp
If the protocol selected is the BSD print protocol, you may further select the order of sending the control file to the printer. Some printers expect the control file, then the data file; others the reverse. See the printer vendor documentation for this information. The default is to send the control file first.
The command to select the ordering is:
lpadmin -p printer_name -o bsdctrl=first
or
lpadmin -p printer_name -o bsdctrl=last