If this optional parameter is set, it forces a particular port number to be used for the forwarding port. Therefore if you have, for example:

OutPort 1001

Then all requests forwarded will appear to come from port 1001 on this Radiator host. This can be useful for implementing strict firewall rules. The argument may be either a numeric port number or an alphanumeric service name as specified in /etc/services (or its moral equivalent on your system). The default is to use a port number determined by your operating system, which will typically be different every time you restart your Radiator. OutPort may contain special formatting characters. A typical use of special formatting characters is with GlobalVar and command line arguments.