[Freeswitch-users] Call monitoring

I am writing a "call monitor", something like an operator panel. I am capturing events via esl in php, filtering down the data and then sending them to a javascript UI via websocket. My problem is that I am totally bewildered by the amount of events that fs generates, and I'd like to filter it down to a bare minimum. New outgoing call (with uuid, extension and dialed number) Call answererd from other party Line busy Call hung up from either party. Can anyone give me a pointer to which events I really need to monitor, and which fields inside? I will obviously share finished code!