[Freeswitch-users] calls remain connected after conference initiator hangs up

Hi, i have a little problem that i m sure it is easy to fix , my extensions make conferences (the confonference button on the phone) and/or transfers and then they hag up but the others in the conference remainconnected, so this is provoking some people to abuse by connecting their friends through the company PBX and then they hang up and leave the friendsconnected in the call ... i have not succeeded so far in finding how to fix this. Also, it is possible to allow to transfer calls from outside to inside and/or inside to outsidebut not to transfer calls from outside to outside ?thanks!