I just started at a new company about 2 months ago. We have a Cisco 1720 router that belongs to us for our T-1. The Cisco IOS is 12.0(3)T, which is older. All of the sudden in the last weed and a half it has stop routing traffic twice. I can't ping its interface, the only thing that makes it work again is shutting it off and turning it back on. Any ideas?