Hello, thanks for taking the time to contact us today - let's see if we can help optimize your connection!
First off, are you using a wireless connection? Using wifi is not recommended for online play, and can be the cause of many connection problems.
Can you double check your in-game NAT type and bandwidth? Multiplayer--> Options--> Back Button(Xbox) or Select Button (PS3)
Can you also run tests at speedtest.net and pingtest.net and post the results here?
This info will help us determine how we can best configure your setup.