Hello, my company is a single site with a 2600 series router. Our internet keeps going down periodically through out the day. I can ping locally, but not on the WAN (ie yahoo). Our ISP will only ping their circuit and not our router, so they are useless in this situation. When i am working form home this happens and i loose the connection. At that time i cannot ping the public IP on the WAN port of the router. Is it possible that the CSU\DSU card is going bad?