Reduce chunk HEARTBEAT

I had code app transfer file with SCTP, I try test performance of my app with loss packet rate 0% app run ok.But with loss packet rate 10%, sometimes my app only send chunk HEARTBEAT and don't send data any more. I don't know how to reduce chunk HEARTBEAT send on association.I'm using LKSCTP 1.11 with Fedora 11 and Linux kernel 2.26.29. I am using iptables to simulate loss packet and present I am testing on interface lookpack. Thanks a lots.