Reprinted from: http://www.aspx2.com/article/20101126/20101126024002951.html
To allow the Silverlight control to access services in other domains, the Service must explicitly allow cross-origin access. Silverlight 4 supports two different mechanisms for Service Selection for cross-origin access:
Place a clientaccesspolicy. xml file in the root directory of the domain hosting the service to configure the service to allow cross-origin access.Place clientaccesspolicy. XML in Apache-Tomcat-6.0.20 \ webapps \ Root
Place a valid crossdomain. xml file in the root directory of the domain hosting the service.
Here we use clientaccesspolicy. xml. The content is as follows:
Clientaccesspolicy. xml
<? XML version = "1.0" encoding = "UTF-8"?>
<Access-Policy>
<Cross-domain-access>
<Policy>
<Allow-from http-request-headers = "soapaction">
<Domain uri = "*"/>
</Allow-from>
<Grant-to>
<Resource Path = "/" include-subpaths = "true"/>
</Grant-to>
</Policy>
</Cross-Domain-access>
</Access-Policy>