Help with slow network.

Good Evening,

I am here today in hopes that someone might be able to guide me in the correct direction. I am having slow networking issues. I seem to have a good connection when it comes to smaller things. Web pages load quickly, downloads move fairly quickly, and multiplayer games usually work alright in specific instances, i.e. co-op, small 5 man games, things that don't require AS much connection. Yet once I get into a multiplayer game of lets say, Call of Duty: World at War, my connection is horrible. I am lucky to get 2 out of 4 latency bars. It's so bad to the point that I will shoot at someone and die, then see the kill cam, and it looks like I just ran out into the open screaming to be killed.

For a little background, this happens with my router or directly connected to my modem. I have noticed that other people, who I assume live in my apartment complex, have been trying to access my public file folder. I don't allow these people to access my files and even turned sharing off as a hopeful preventative. My only assumption can be that it is almost as if my connection is being shared/networked with other people in my complex.

Any ideas, tips, advice, would be greatly appreciated. Thank you all in advance.

EDIT: To my discovery I found out that my ISP splits a T1 line to divvy out bandwidth to residences at my complex. This would probably be why, eh?

most likely the sharing a t1 line...get dsl