Dedicated servers typically run on a PC in the home over a DSL connection. This page will help you set up and get the most out of a dedicated server run from home.

NAT configuration

Servers that run through NAT require the following UDP ports to opened for inbound access: 27900, 27901, 27910. If you plan to run more than one server, enable some other ports too, for example 27920, 27930, 27940.

Please make sure that your Windows/Linux firewall also allows these inbound UDP ports.

DSL line configuration

DSL lines often use a technique called "interleaving" to improve line stability and robustness. However, this typically adds 30ms to the connection between the home PC and the ISP, which is bad for both playing Alien Arena, and serving dedicated servers.

For stable lines this can usually be turned off safely - ask your ISP or telecoms provider to do this for you.

How can you tell if your line is interleaved?

Your router should tell you under the DSL line status page. Look for "interleaved" or "fastpath".

Alternatively, use traceroute to a server on the internet. If the first hop (your DSL connection) is around 30ms, then it is likely that interleaving is enabled on your line.

Quality of Service 

Since you''re likely to use your connection for activities other than serving Alien Arena, it''s a good idea to prioritise game traffic over web and ftp traffic. Many routers will allow you to do this using Quality of Service (QoS). Look for these pages in your router configuration. You should be able to either prioritise UDP traffic on the ports you defined above, or at least reduce the priority of web (TCP port 80) and ftp (TCP port 21) traffic.

Bandwidth considerations

Monthly UDP bandwidth usage per player per month = 9.5 GiB (assuming always connected)
Average throughput = ~3872 bytes/sec
Traffic is 67% inbound, 33% outbound

Results obtained 7th March 2007 using iptraf.
An uninterrupted CTF game between two average players alongside four bots was monitored over ten minutes, and values derived from those statistics.

EuroArena, one of the more popular dedicated servers, shifts between 40-60Gb/month in games traffic alone.

Server configuration

Server game type and rules are defined in .cfg files in the /arena/ subdirectory. Typically a different config file would be created for each server that is run.

For example, "myconfig.cfg" might be configured like this:

set port 27910
set dmflags 540688
set hostname "Example Server"
set website "http://www.myhomepage.com/" s
set Admin "Admin" s
set deathmatch 1
set maxclients 16
set maxspectators 2
set fraglimit 20
set timelimit 20
set sv_maplist "dm-dynamo2 tourney0 dm-vesuvius dm-furious"
set sv_public 1
set logfile 1
set allow_download 1
set allow_download_maps 1
set allow_download_models 1
set allow_download_players 1
set allow_download_sounds 1
set rcon_password "password"
setmaster master.corservers.com master2.corservers.com
map dm-dynamo2

set sv_botkickthreshold XX

Anti-camp can be turned on like this:

set anticamp 1
set camptime 5

camptime is the number of seconds a player has to stand in one place before a warning is issued and health starts to reduce.

Server options

DMFLAGS

Below is a table of dmflags supported by the CRX engine.

Normally these would be added together to give the resulting dmflags value, but to reduce the guesswork, use the DMFLAGs calculator here.

Launching a server in Windows

Under the main game directory, create (or copy and modify) a myconfig.bat file, containing the line:

crx +set game arena +set dedicated 1 +exec myconfig.cfg