I have 2 A-800P with all port is FXO in a PC. Only one channel (say channel 3) is plugged to PSTN. In my understand, a dial command
Dial(zap/g1/12345677) should search an available channel, which is 3, in group 1 to make a call. However, I found that it will still use channel 1 to make a call even it hasn't plugged to the PSTN. Below are the conf files.
