Configuring a Client Access Policy File

By default, Silverlight applications will not be able to connect to the Visualization Service unless an appropriate ClientAccessPolicy file is served to them. Whenever the Silverlight application attempts to connect to a Visualization Service instance, the Silverlight framework will attempt to download a Client Access Policy file from port 943 of the server (for example, if the client is connecting to then Silverlight will attempt to download a client access policy file from

The client access policy file dictates which Silverlight clients are allowed to connect to the visualization service. The default ClientAccessPolicy.xml file included with the Visualization Service allows all TCP connections to port 4530 for any client. You can modify this file to restrict access to clients.