Guys, now that we resolved that the DTF should call the "GetAvailableProtocols()" operation on the source and sink data services. This is all fine and can be "WSDL-ized" fairly quickly. However, what do we do with the Credentials that the client of the DTF needs to pass into the DTF for it to properly instantiate the data transfer? I guess the signature of the DTF's "requestDataTransfer()" operation needs to change here. Cheers, Michel