[Kamailio-Users] SIP Session timeouts

Hi All, I have a question about the best solution to ensure that SIP calls are terminated when the 2 parties drop off the network (wireless). Is there a std way of doing this (maybe using sst module) or should this be implemented using some specialised code? If not supported in a std manner in Kamailio, i thought about creating a child process within the DLG module that continuously checks all dialogs and the connected parties and pings them for connectivity. Should connectivity of any participant drop for more than a specific unit of time then the call is focefully torn down by openser. Any ideas? Cheers Jason