This is totally doable in FreeSWITCH. I'd recommend writing it in a script and using ESL This will give you more control over what's happening. You'll need to spend some time learning the event socket and how to handle events from two related call legs. I highly recommend our book, especially chapter 9. :P You can also hang out in #freeswitch to talk in realtime with the gang. -MC <snip>
Party A calls and party B is called (the phone is ringing at that point)
When party B picks up the phone, FS plays an announcement to party A (ex: callee.wav) and another announcement to party B (ex: called.wav) - bouth announcements/sounds has the same duration If party B stays in the line after heard the announcement/sound FS bridge A and B If party B hangup the phone, party A hears busy tone (could be an announcement too) and the call is dropped.