Call of Duty 4 online multiplayer 4 players at once?

No.

The only way to join their split screen game is to be on the same hub (router) as them.

It's pretty well structured, it's sorted into game mode based playlists, with options for either Core or Hardcore. Hardcore is more tactical, and punishes death more severely whereas Core is the standard game mode, featuring Call of dutys inoviative killcams and whatnot. The playlists aren't rank based, everyone has a rank, actually there are 605 ranks to go through I think, which come in sets of 55. You aren't sorted into teams or games based on these ranks, so if your high rank you can be playing with a guy who's very low. This provides a great multiplayer experience because players who are able to excel, really are able to own the competition, not that more casual players won't be able to find it fun though. The multiplayer is all class based, which means you get to setup your player with weapons of your choosing (there's a wide selection) There are about 18 maps I think, all pretty unique and provide a good combat experience. If it's your first Call of Duty multiplayer you'd want to go with CoD4, World at War is pretty good but is slightly to moderately inferior in every aspect.

No, the only way you could all play together is if ou were each on the same system or each of you had your own system with internet and played