We have cisco router 7302 router where 14 E1 are installed.
Today Router CPU usage hit 93% and it last for 5- 6 hours when it shutdown. Person went to cabinet and found all boards were up (LED Green) and power supply intact. But we can not contact router via WAN and also there was alarm on E1 ports that D-channel error.
Router was restarted after switch OFF and ON again.
Router went down again after 1 hour, and to reduce the load we restricted traffic so that CPU usage remain below 80% and it uses less DSP resources. For last 7 hours no more issue.
My question is what could have happened and how we can prevent?