OAS FALLS DOWN - there may be a reason for opmn to "think" the instance is dead?

Hi

why could be the reasons OAS falls down after a randomtime?

.it work ok for a time, but after 10min, 24hours, so on..falls down suddenly..

.there may be a reason for opmn to "think" the instance is dead?

.one reason, may be that the instance is so busy that it can't respond to opmn's requests?

network interruption?

wrong firewall, network configuration?

bug?

tks in advance!