Please see the locationIPAddress topic for when you would use the locationPort setting (the locationIPAddress setting is required or locationPort is ignored).
When the SEND-LOCATION Telnet option is set to send a specific address using locationIPAddress, the port used to connect can be set using the locationPort setting. The default port of 23 may not be expected and you can set the port using this setting:
<add key="locationPort" value="3200" />
The above example will set the active location port to 3200.