When connecting to an online match, you are connecting directly to another console (peer to peer).
This means there is no server that you connect to when you're hosting or joining a match. The PSN or XBLA servers try to make the best match for you based on certain criteria.
This is commonly referred to as "matchmaking." This matchmaking service will filter different players and their connections so that you have the best online experience from both a quality standard and in some cases filtered based on your skill level.
For games made by us the information below will explain what kinds of things we look for when creating a match between players.
For both the PlayStation 3 and Xbox 360, we look at things like:
Game types - What type of game are you playing? Campaign? Mini-Game? Etc?
Game Mode - Ranked or not?
Players - Maximum number of players
Private - Is this a private match or not?
Nat Type - See: NAT Section
The game tries to match these attributes, regardless of the connection speeds or location- they are just trying to find someone who wants to play what you want to play.
At this point we gather about 10 matches and within those 10 we look for ping times under 350ms and add them to a possible join list. If within these collected matches a game is full you would move down the list of matches until one is available for you to join. If none are found you will receive one of the following messages:
"No games found"
"Game is full"
"Game is no longer available"
"Not enough open slots in this game"