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diff --git a/docs/multiplayer.md b/docs/multiplayer.md new file mode 100644 index 000000000..89a490602 --- /dev/null +++ b/docs/multiplayer.md @@ -0,0 +1,213 @@ +# Multiplayer manual for OpenTTD + +Last updated: 2011-02-16 + + +## Table of contents + +- 1.0) [Starting a server](#10-starting-a-server) +- 2.0) [Connecting to a server](#20-connecting-to-a-server) + - 2.1) [Connecting to a server over the console](#21-connecting-to-a-server-over-the-console) +- 3.0) [Playing internet games](#30-playing-internet-games) +- 4.0) [Tips for servers](#40-tips-for-servers) + - 4.1)[Imposing landscaping limits](#41-imposing-landscaping-limits) +- 5.0) [Some useful things](#50-some-useful-things) +- 6.0) [Troubleshooting](#60-troubleshooting) + + +## 1.0) Starting a server + + - Make sure that you have your firewall of the computer as well as possible + routers or modems of the server configured such that: + - port 3979 is free for both UDP and TCP connections in- and outgoing + - port 3978 is free outbound for UDP in order to advertise with the master + server (if desired). Otherwise you'll have to tell players your IP. + - port 3977 if use of the admin interface is desired (see admin_network.txt) + - Click "multiplayer" on the startup screen + - Click "start server" + - Type in a game name + - Select the type of game ('LAN/Internet' or 'Internet (advertise)'. With the + last one other people are able to see you online. Else they need your IP and + port to join) + - Click "start game", "load game" or "load scenario" + - Start playing + + +## 2.0) Connecting to a server + + - Click "multiplayer" on the startup screen + - If you want to connect to any network game in your LAN click on 'LAN', then + on 'Find Server' + - If you want to see which servers all online on the Internet, click on + 'Internet' and 'Find Server' + - If there were more than one server + - select one in the list below the buttons + - click on 'join game' + - If you want to play and you have the ip or hostname of the game server you + want connect to. + - click add server + - type in the ip address or hostname + - if you want to add a port use :<port> + - Now you can select a company and press: "Join company", to help that company + - Or you can press "Spectate game", to spectate the game + - Or you can press "New company", and start your own company (if there are + slots free) + - You see a progressbar how far you are with joining the server. + - Happy playing + +## 2.1) Connecting to a server over the console + + - Open the console and type in the following command: + connect `<ip/host>:<port>#<company-no>` + + +## 3.0) Playing internet games + + - Servers with a red dot behind it have a different version then you have. You + will not be able to join those servers. + + - Servers with a yellow dot behind it have NewGRFs that you do not have. You + will not be able to join those servers. However, via "NewGRF Settings" and + "Find missing content online" you might be able to download the needed + NewGRFs after which you can join the server. + + - It can happen that a connection is that slow, or you have that many clients + connected to your server, that your clients start to loose their connection. + Some things you can do about it: + - [network] frame_freq: + change it in console with: 'set network.frame_freq <number>' + the number should be between the 0 and 10, not much higher. It indicates + the delay between clicking and showing up. The higher, the more you notice + it, but the less bandwidth you use. + A good value for Internet-games is 2 or 3. + + - [network] sync_freq: + change it in console with: 'set network.sync_freq <number>' + the number should be between the 50 and 1000, not much lower, not much + higher. It indicates the time between sync-frames. A sync-frame is a frame + which checks if all clients are still in sync. When the value it too high, + clients can desync in 1960, but the server detects it in 1970. Not really + handy. The lower the value, the more bandwidth it uses. + + NB: changing frame_freq has more effect on the bandwidth then sync_freq. + + +## 4.0) Tips for servers + + - You can launch a dedicated server by adding -D as parameter. + - In UNIX like systems, you can fork your dedicated server by adding -f as + parameter. + + - You can automatically clean companies that do not have a client connected to + them, for, let's say, 3 years. You can do this via: 'set autoclean_companies' + and 'set autoclean_protected' and 'set autoclean_unprotected'. Unprotected + removes a password from a company when it is not used for more then the + defined amount of months. 'set autoclean_novehicles' can be used to remove + companies without any vehicles quickly. + + - You can also do this manually via the console: 'reset_company'. + + - You can let your server automatically restart a map when, let's say, year 2030 + is reached. See 'set restart_game_date' for detail. + + - If you want to be on the server-list, enable Advertising. To do this, select + 'Internet (advertise)' in the Start Server menu, or type in console: + 'set server_advertise 1'. + + - You can protect your server with a password via the console: 'set server_pw', + or via the Start Server menu. + + - When you have many clients connected to your server via Internet, watch your + bandwidth (if you have any limit on it, set by your ISP). One client uses + about 1.5 kilobytes per second up and down. To decrease this amount, setting + 'frame_freq' to 1 will reduce it to roughly 1 kilobyte per second per client. + + - OpenTTD's default settings for maximum number of clients, and amount of data + from clients to process are chosen to not influence the normal playing of + people, but to prevent or at least make it less likely that someone can + perform a (distributed) denial-of-service attack on your server by causing + an out-of-memory event by flooding the server with data to send to all + clients. The major factor in this is the maximum number of clients; with + 32 clients "only" sending one chat message causes 1024 messages to be + distributed in total, with 64 clients that already quadruples to 4096. Given + that upstream bandwidth is usually the limiting factor, a queue of packets + that need to be sent will be created. + To prevent clients from exploiting this "explosion" of packets to send we + limit the number of incoming data, resulting in effectively limiting the + amount of data that OpenTTD will send to the clients. Even with the default + limits it is possible to generate about 70.000 packets per second, or about + 7 megabit per second of traffic. + Given that OpenTTD kicks clients after they have not reacted within about 9 + seconds from sending a frame update packet it would be possible that OpenTTD + keeps about 600.000 packets in memory, using about 50 megabytes of memory. + Given that OpenTTD allows short bursts of packets, you can have slightly + more packets in memory in case of a distributed denial of service attack. + When increasing the amount of incoming data, or the maximum number of + clients the amount of memory OpenTTD needs in case of a distributed denial + of service attack is linearly related to the amount of incoming data and + quadratic to the amount of clients. In short, a rule of thumb for, the + maximum memory usage for packets is: + #max_clients * #max_clients * bytes_per_frame * 10 KiB. + +### 4.1) Imposing landscaping limits + + - You can impose limits on companies by the following 4 settings: + - terraform_per_64k_frames + - terraform_frame_burst + - clear_per_64k_frames + - clear_frame_burst + + - Explaining 'per_64K_frames' and 'burst' + - 'burst' defines 3 things, the maximum limit, the limit of a single action, + and the initial value for the limit assigned to a new company. + This setting is fairly simple and requires no math. + + A value of 1 means a single tile can be affected by a single action. + This results in having to click 400 times when wanting to cover an area + of 20 x 20 tiles. + + The default value 4096 covers an area of 64 x 64 tiles. + + - 'per_64k_frames' defines the number of tiles added to each companies limit + per frame (however not past the possible maximum value,the 'burst'). + 64k rather resembles the exact number of 65536 frames. So setting this + variable to 65536 means: 65536 / 65536 = 1 tile per frame. + As a day consists of 74 frames, a company's limit is increased by 74 + tiles during the course of a single day (2.22 seconds). + + To achieve a 1 tile per day increase the following calculation is needed: + 1 / 74 (frames per day) * 65536 (per_64k_frames) = 885.62... + after rounding: a value of 886 means adding a bit over 1 tile per day. + + There is still enough space to scale this value downwards: + decreasing this value to 127 results in a bit over 1 tile added to the + allowance per week (7 days). + + To create a setup in which a company gets an initial allowance only, + set the value to 0 - no increase of the allowance per frame. + + - Even though construction actions include a clear tile action, they are not + affected by the above settings. + + +## 5.0) Some useful things + + - You can protect your company so nobody else can join uninvited. To do this, + set a password in your Company Screen + + - You can give other players some money via the ClientList (under the 'head' + in the mainbar). + + - You can chat with other players via ENTER or via SHIFT+T or via the ClientList + + - Servers can now kick players, so don't make them use it! + + +## 6.0) Troubleshooting + + - My advertising server does not show up in list at servers.openttd.org + Run openttd with the '-d net=2' parameter. That will show which incoming + communication is received, whether the replies from the master server or + communication from an admin tool reach the programme. See section 1 + 'Starting a server' further up for the ports and protocols used by OpenTTD. + The ports can be configured in the config file. |