[Freeswitch-users] sending BYE due to ACK timeout

Hi, My freeswitch is sending out a BYE signal due to ACK timeout even though there is already audio . The audio gets cut off after around 30 seconds, I think it detects RTP timeout. It's wierd because I already picked up the call and I can already do conversation but after 30 seconds it just cuts it off. Is there any solution for this? Im using freeswitch 1.5 btw. Thanks, Jason