I am planning to connect a Nextel phone to a Asterisk FXO port using a Phonelabs docking station but, this dock station use ‘flash’ to simulate the PTT button. Is it possible that Asterisk translate # or * key to ‘flash’?
What kind of phones are you calling from? This might be a programable feature on the phones that you will be accessin the dock and talk with unless im thinking of a different situation asterisk does ahve the ability to send a flash see here