1.  Open the preferences.  This may be in a different location depending on your version of Real Player.  Here are screen shots of version 7 and RealOne.

2.  If you have RealOne Player, select Proxy under the Connection Category.  Check the box that says RTSP proxy and for address type proxy.amphi.com and for port type 554.  PNA proxy should be unchecked.  For HTTP Proxy select use system Internet Connection Proxy Settings.

If you have RealPlayer 7, select the proxy tab at the top of the box.  Check the box that says RTSP proxy and for address type proxy.amphi.com and for port type 554.  PNA proxy should be unchecked.  For HTTP Proxy select use my web browser's HTTP proxy.