Dead Sockets

Hello

We are a danish telco, and we are having problems with large amounts of dead sockets, generated by Asterisk.
Does anybody know what is causing this, and what can fix it. It takes around 2-3 days, and then we have around 200 dead sockets.
An Example:

asterisk 7422 root 124u sock 0,5 87322807 can’t identify protocol
asterisk 7422 root 134u sock 0,5 89643960 can’t identify protocol
asterisk 7422 root 138u sock 0,5 87463270 can’t identify protocol
asterisk 7422 root 140u sock 0,5 89278131 can’t identify protocol
asterisk 7422 root 141u sock 0,5 89204248 can’t identify protocol
asterisk 7422 root 142u sock 0,5 89243933 can’t identify protocol
asterisk 7422 root 143u sock 0,5 89354198 can’t identify protocol
asterisk 7422 root 146u sock 0,5 88068514 can’t identify protocol
asterisk 7422 root 148u sock 0,5 89188035 can’t identify protocol

We do have a large amount of trafic, and its very anoing that we have to restart the server every few days.

Regards
Jon