This is the exact project from SIP r&d (asterisk,ser,yate) is project number 46911. I want the same application. Basicly. To put it more sample, I make a call trough SIP, it goes trough a custom-trunk. Then from the custom-trunk we create a script. That makes another call to the right destination. We do a Voice Activity Detection. If theres a voice, then we bridge the 2 calls together. So we if theres voice we connect. If its rings we let ring, we dont connect. If its busy, we return the hangup. It has to have the ability to detect ring or busy. If its not those 2 then its connect.