The port number is 20051.
To test to check whether the router is blocking the Scala port # 20051 you can type in the command prompt Telnet, then the name of the player or player IP Address, and port # 20051. It will make a temporary connection if it is correct or you will get a Service Unavailable message if it failed. Cause of the failure could be the Router is blocking the port, no TCPIP, or the Player is running.
Examples:
TELNET 255.255.100.23 20051
TELNET \PlayerName 20051