The variable SERVER_PORT specifies a particular port number to be used for accessing acuserve on the server host machine. This is especially helpful when the server host machine has a security firewall, because firewalls generally allow access only to specific ports. With this variable, the site can ensure that firewall restrictions are satisfied.
The acuserve daemon or service can work with privileged port numbers (from 0 to 1023) and non-privileged port numbers (1024 and higher, up to 32767).
The value of this variable is overridden by any port number assigned on the command line (via the -n option) when acuserve is started.