PPP type interfaces may also be used in pfSense® software. These are not to be confused with PPPoE or PPTP interfaces, as these are traditional PPP on serial devices.
This will commonly be used to drive 3G modems for wireless WAN access, but could also be used for controlling dialup modems.
The parent interface of a PPP interface is a serial device. Check the System Logs </monitoring/system-logs> or the output of the "dmesg" command to see which serial device should be used.
There are some pre-defined connection profiles available for cellular modems from certain providers, click the links to fill in the information automatically.
Depending on the equipment and provider, some settings may not be necessary and others may be required. Check with the provider, Google, or the pfSense forums for more information if there is not a profile available for a specific network.