I have to develop a WCF application in 3.5. The input will be sent in the form of XML and the response would be sent in the form of XML as well. A ASP.NET application will be consuming the WCF and sending/receiving data in XML format.

Now, as per my understanding, when consuming WCF from an ASP.NET application, we just add a reference to the service, create an object of the service, pack all the necessary data(Data Members in WCF) into the input object (object of the Data Contract) and call the necessary function.

It happens that the ASP.NET application is being developed by a separate party and they are hell bent on receiving and sending data in XML format. What I can perceive from this is that the WCF will take the XML string (a single Data Member string type) as input and send out a XML string (again a single Data Member string type) as output. I have created WCF applications earlier where requests and responses were sent out in XML/JSON format when it was consumed by jQuery ajax calls. In those cases, the XML tags were automatically mapped to the different Data Members defined.

What approach should I take in this case? Should I just take a string as input (basically the XML string) or is there any way WCF/.NET 3.5 will automatically map the XML tags with the Data Members for requests and responses and I would not need to parse the XML string separately?