is it possible to set different ringtones for the FXS ports. So you can hear if it is an external or internal call. Same as "distinctive ringtone".
[bell]
exten = 80,1,Wait(1)
exten = 80,n,Dial(DAHDI/4r2,60,iTtKkXx) ; ' r2' = ring pattern 2 for bell '4' = FXS port 4
exten = 80,n,Hangup()