How do I play Modern Warfare 3 with my friend online?

Hopefully this topic won't get removed. My friend and I were trying to figure this out at the internet cafe earlier. Basically, the cafe has no steam so we can't play LAN but we can play online. The problem is though, we can join the same hosted game. We can play separate games without problems but the minute I try to join the game my friend is in, his connection gets timed out and my pc just stays at connecting to server screen. Why is this happening and is there anyway around it?

Um... definitely going to need more information. "the cafe doesn't have steam"? Are you using your own computer? Is your friend using his own computer? Do you both have separate copies of the game?

The game is installed on both of the computers you're using? Is it like one of those places where there's a bunch of gaming systems set up, and people pay by the hour to play?

Then there should be someone there who can make it work. 

Well then you should probably let them know their business sucks, by leaving, and not giving them any more money/patronage.