Cisco network and OpenNMS

Hi,

We've discovered a strange behavior on our Network's OpenNMS reports for TCP Errors and Failures.

Every day, we get an "outrsts" spike on every node that we have SNMP monitored, routers, switches and non-Cisco devices. The time of the spike varies on each piece of equipment but always seems to happen every 24 hours for each.

Does anyone know why this is happening?

Thanks