[Freeswitch-users] Odd situation bridge

Hi, I have this situation: 1) Leg A calls Leg B 2) Leg B answers 3) Start exchange media but here is the problem: a) Leg B starts with silence and after that starts ringtone (but understand you are inside a bridge) The question: How can I bridge A with B only when I receive from Leg B the inside ringtone (when it answered). Consider in this situation -When Leg B answers it produces silence and after that ringtone and after that the person from the other side- . Thanks a lot