[Freeswitch-users] Zap dialplan

All the examples show bridging calls to an fx(s|o) port, but none show how to handle an incoming call from the pstn on an fxo port. How do you distinguish this call in your dialplan and begin routing it? Does fs just place it in the public context, and if so iirc pstn calls don't have a "destination_number" to match on, but a caller id only? Thanks, jlc