The term "phonepatch" usually refers to the hardware device used to
connect a radio transceiver and a phoneline. Asterisk-phonepatch do that task, but it's mainly software, as it uses Asterisk (the EAGI mode), sox as sound converter and festival as text-to-speech syntetizer.
Anyway, you need to setup some hardware interface between computer and radio, to control audio (using the soundcard as D/A, A/D converter), PTT (Push-to-Talk) and -optionally- carrier detection.
These details are provided for information only. No information here is legal advice and should not be used as such.