[Freeswitch-users] Hangup on silence?

Hi, is there a way to hangup after a certain amount of silence? my problem is that with regular PSTN calls I don't get a BYE from my provider until around 1 minute after the phone has been hanged up. This is pretty standard, and the provider is not at fault, but I would like to hangup the call after I detect a certain amount of silence time. The only thing I could find was wait_for_silence on the wiki, but that application only delays dialplan execution, and I would need something like: hangup_on_silence=30, where 30 means to hangup if 30 seconds of silence have passed. Thanks for your help! Nicolas