I just hate it when you call, accept the call, then you are denied because of some stupid it can not connect to host message ... Now you would think that when such a deficiency is prevalent in the original series would continue to disappear by the time came. Unfortunately, this is not the case. This is because the failure to write this guide for help.
Trick 1: Turn your Playstation 3 and then. This is my quick fix, and it usually works though, if you should continue reading. Make sure though that if you get invited you to wait while you are connected to the match making server and you are in the lobby, where you can change your class and pick up the game
Trick 2: Make sure that everyone in the party have downloaded the latest updates. This usually means that the whole team will have to turn off the console, so that they get the updates. This problem can be a little difficult to spot and usually happens only when an update is present.
Trick 3: Get everyone in the party to invite you. This is a very efficient way to get past this problem, but it does not get rid of the problem. The player who could not call you and still not be able to invite to a party. No, this trick has helped me a lot in the past.
Trick 4: Try to join a party meeting. This means that none of them to invite you, but I still could possibly play with them. If your friends stay in the same lobby, game after game you'll have to join a lot of sessions and it usually does not work as sometimes their game could be full.
These are all tricks I know to overcome the dreaded can not connect to host problem. If I find more I'll tell you!