Gateway offline!?

Okey so my msn messenger has been unvailable for the last days. And it is starting to annoy me. I thought at first that msn was down, and that everyone had this problem, but I soon figured out otherwise.

So… when I try to log on I get this message that wants me to troubleshoot. So I did. And it says that my gateway is offline.

First of all, how do I make it online, and what is is:P lol