OSPF drops

Hey Guys,

I have a network problem which I am hoping you can shed some light on.

I work for an ISP and I have strange issue with one of the routers that we manage. From this router we run OSPF to our upstream PE and run LDP as well. The issue we are seeing is that the OSPF keep going from Loading to full on the CPE:

GigabitEthernet0/0.100 from LOADING to FULL, Loading Done

On the upstream PE we see the following:

GigabitEthernet0/1.100 from FULL to DOWN, Neighbor Down: Dead timer expired

The CPU on the router does spike occasionally, but not at the time of the drop. I am thinking that it may be due to a sudden burst of traffic causing saturation of the link, causing the OSPF to drop. Saying this however, the LDP neighbor doesn't/hasn't dropped and this forms via the same physical link as the OSPF does.

I have configured an EEM script on the router to try and give me a bit more info, but nothing has been generated yet. Im just wondering if it's possible for me QoS the OSPF packets generated from the router. Also if you have an troubleshooting tips they would be much appreciated.

Thanks