Gateway Down

Morning Folks. Hoping someone can explain this to me.

Been having a few connectivity issues over the past week or so. End result was my ISP (KeConnect) got Openreach down to my exchange on Friday where the line card was reset. After the reset, all seemed good again. Spent the weekend synched at about 1700Kbps with a noise margin of 6db or so.

Got home last night, and saw a red light on my router (a Linksys WAG200G, which I'm not exactly loving). Checked the router stats, and although I was still synched at about 900Kbps, and the noise margin was about 12db, I had no connectivity. The router status said the "gateway" was "down". I rebooted the router, which eventually brought the "gateway" back "up" after about 5 mins.

What does this mean?

Kevin.