[Freeswitch-users] RTCP Keep Alive issue - hangup after 60 seconds of silence

Hi, Have encountered a problem recently where the company responsible for forwarding sip calls to my switch has started hanging up calls when there is more than 60 seconds of silence on one side of the call. As my service is primarily used for recording incoming messages, this means that any message being recorded longer than 60 seconds gets cut off. My provider says I need to configure freeswitch to send rtcp keep-alive packets to prevent them from hanging up the call. Can anyone tell me how I can do this, I've checked the docs and can't seem to find the right setting? Many thanks Andy