Howto direct pickup/connect to Zap trunk from SIP extension

I have a fully working Asterisk 1.4 set up: 3 SIP trunks, including POTS trunk inbound and outbound (dial 9+), all working. All the VOIP trunks are my business; the POTS is the family line. POTS is on a TDM400P with one FXO module.

I would like to be able to dial an extension or feature code from my Aastra SIP phone that then simply connects to the POTS FXO trunk (Zap channel 1), and then does nothing else. The functional equivalent of just taking an analog phone off-hook. My need is to a) join a call already on the POTS line, or b) see if there messages on that line (with messages you get an intermittent dial-tone when picking up any analog phone).

How is this done? My Asterisk is on a PIAF/FreePBX 2.5 system, in case there is a GUI way to do this, but I’m happy going into the config files too.


/s/ Martin