Last updated: 01.09.2011
Error message: Operation timeout.
In most cases this problem is related to the multiplayer actions. Either connecting to game server, session master has timeouted, or registering/unregistering of the player car has failed because no answer from other side. Standard connection checks from problem 1500 could apply.
Relevant information:
In multiplayer basically there are 3 sides involved:
Game server - hosted on our site, collecting information about all people logged in into multiplayer and also about all running sessions (IP addresses, ports, classes etc.) It's responsible for distribution of all session lists to your multiplayer join session or show sessions dialoques as well as meeting room chat.
Session master - Racer who creates session, quality of that session is then declared by his upstream bandwidth mostly (please read about it more here), every client then connects to this session master, through him is going the traffic between all clients (position packets synchronization) and he decides when to start race procedure or else.
Session client - every other racer connecting to session master
So according to this game server is not under heavy traffic load. Important is, that each client must be able to connect to master IP address to port 26381. If this is not possible (as often users are behind NAT, broadband DSL router or so) and as default these systems are denying not initiated from inside connections to that port, another technique called NAT punch-through comes on scene. For connection success most ensuring should be to open port 26381 from outside Internet to your PC to your local IP and also be sure nothing on your PC is blocks it.
To give a bit more light into bandwidth area. According to last tests we did in this area we can say, that every car in multiplayer session produces aproximately 25kb/s of data stream. That means every client sends that to session master. It is not critical as it affects downstream of session master. But what happens then is critical for session master's upstream, because he needs to 'broadcast' to all session cars all position packets of all cars except that car who he sends data to (as that car already knows his own position already). Hehe, difficult sentence, but hopefully you know what I mean.
Formula for master upstream bandwidth usage looks then like this:
n - number of client cars in master's session
usage (kbps) = (n * 25) * n
So if you have let's say 8 cars (7 clients + 1 master) then master's upstream bandwidth usage is:
(7 * 25) * 7 = 1225 kbps
So in session with 8 cars master must have aproximately at least 1.2 Mbit upstream connection, now not including other traffic at all (messengers, voice chat programs, other downloads which also need a bit of upstream too, another home PC in LAN producing also bandwidth usage etc.) And it is also good to count with some reserve. In other words - quality of multiplayer experience has it's cost, at the moment we need quite a lot of data to be send in and out. But as said, this is not the final state, we'll try to improve it of course.
See example of bandwidth calculation: www.vrcworld.com/member/tip.aspx?member=274&topic=1730#detail
Also the more cars already in session and weaker PC configuration user has, the more time needed to build all client cars already in the session he's connecting it could take and eventually it could time out"
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