Best CPM banner network for international traffic

HI
I looking for weeks to fnd a good CPM network that counts international traffic and has no joining requirements.
I used AdBrite on my website but i needed to remove it again because is slowed my website down and if the AdBrite server was down the website did only load half so there is no way that i would put a Ad script like this on my website.
But i have a hard time to find a AdBrite alternative hop some people can help me in finding one. :/

See original post by Mike80