You can try it just following these simple steps:
- open the solution using Visual Studio 2008;
- deploy the Wcf Service “DuplexService” to http://localhost/DuplexService;
- copy the included crossdomain.xml and clientaccesspolicy.xml in c:\inetpub\wwwroot\;
- run the project “DuplexClientWeb” from within Visual Studio or deploy it to IIS.