I have some integration scenarios where my ERP System exchanges messages with PI through RFC Sender Channel. The problem is that sometimes my RFC destinations (transaction SM59 of my ERP System) stop working. Sometimes they do not stop working but when I test them (with "Test Connection" button) the response time is VERY high! Well in both situations I have to restart my communcation channels (stop/start channel in RWB). Do you have any idea of what could be the cause of this problem? I found some wikis on SCN where people say that destinations stop working because of network problems/issues. But I am not sure that this is the cause because I have two ERP and two different PI Productive Systems and the problem always happens with one of them.
Amit gives you a good point to start but if i was you can wonder to migrate the sender RFC to sender ABAP proxy. I had the same problem, the problem often occurred when any exception appears, the sender RFC was stopped, with abap proxies the performance is better and i havent any problem.