Not sure if to be posting here, but I'm having some problems if anyone can offer a solution.. Randomly, and quite often I will get disconnected from Xbox live and then can't connect for another 15 minutes. I'm port forwarded, but still have problems and my router is up to date.
Power cycle your modem and router. This means you unplug them both (pull the cord from the unit, not the wall) and wait 5 minutes. Then reconnect everything. Works 99% of the time. If that doesn't work: http://support.xbox.com/en-US/xbox-live/connecting/performance