For bypassing blocked ports in other networks, try changing the Radio Server port to something that you know works, ie 8000, 8080, etc... normally those are allwoed for HTTP access. One static port that must be open in 843, this is a static port set by Adobe. Flash player connects to a "Policy server" checking an XML file for permissions before it attemps to connect to RCForb. This a required security measure that Adobe has integrated into their software for Flash based applications to make socket connects.
So if port 843 is blocked, you will not be able to use a Flash based client that runs in your web browser. A windows based client is already in the making. Screenshot below...
