I wonder how can I achieve this without UDP, I have a solution using UDP multicast: http://blogs.msdn.com/b/ncl/archive/2009/11/18/udp-multicast-in-silverlight-4.aspx but since this is for a high profile customer who has an intranet with port TCP 80 and TCP 8080 only enabled this solution is not possible. Yes, the application runs in an intranet environment.
I need a simple example how to send messages to all Silverlight clients over WCF.
I found this solution, but I have no idea how to implement that into Silverlight:
http://idunno.org/archive/2008/05/29/wcf-callbacks-a-beginners-guide.aspx
I'm out of ideas guys, please help.