Why cant i find anyone in matchmaking on xbox live so theres gotta be a problem with my connection?

im trying to play blackopps and when i go to matchmaking noone shows up at all ive tried going back in and out like 100 times still same problem i was at my freinds house before and he had his wii trying to connect at the same time and as soon as he turned the thing off that connects wii to onlione i could then find matches so does having 2 devices have anything to do with that i dont think that there is anyhting else trying to onnect to my xbox anyways but just wondering so wat can i do to find matches it said somewhere my connection has a strict nat type or something like that and it may influence matchmaking so could u tell me how to change my nat type to less strict so i can please. thanks!