Random disconnects. multiple Event type code 16 and 24. 2 hour lease time

I am getting random disconnects.  I have MB8600 and it has been working fine for 2 years.  All of a sudden am experiencing random disconnects to the internet.  Looking at the modem log showing multipe Notice Event type 16 and 24 codes on chan id 193.  Also the lease time is now at 2 hours instead of the 7 days previously.  How do I get this resolved?