RadDataServiceDataSource does not communicate with the server directly. Instead it uses the built-in WCF Data Services class DataServiceContext to communicate with the server. So if the DataServiceContext is capable of what you need, then the answer should be yes.
This topic explains how you can configure the DataServiceContext to use authentication.
And I believe that this topic will directly answer your question.
If you want to learn more about the new RadDataServiceDataSource controls and experiment with a sample project, please take a look at my blog post.
I hope this helps.
All the best,
the Telerik team
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