Posted: Sep. 23, 2002

A new developer toolkit, the Web Services Development Kit (WSDK), has been posted to MSDN. The WSDK is an add-on to the .NET Framework that supports three GXA protocols: WS-Security, WS-Routing, and WS-Attachments (along with Direct Internet Message Encapsulation, or DIME). The WSDK consists of a set of extensions to the .NET Framework base class libraries that supports the protocols, along with documentation and a set of tutorials.

In order to send a message that uses these protocols, the developer must either annotate the Simple Object Access Protocol (SOAP) message with additional information (such as routing information or security credentials) or alter the contents of the message itself (such as encrypting). The receiver must then reverse the process on inbound messages. The WSDK automates some of this process by providing class libraries to both annotate SOAP messages and to extract the information that was added.

The WSDK, however, has significant limitations that make it more suited for experimentation than application deployment. First, the protocols are not yet supported by Visual Studio or by platform vendors other than Microsoft. Second, even when both participants in an exchange are using the WSDK, the description information generated by the WSDK (known as the Web Services Description Language, or WSDL) does not indicate how the protocols are being used. Clients that query the WSDL, therefore, would have no idea that routing information is being transmitted or that a Kerberos ticket has been attached and must instead know, in advance, what protocols are used and how to respond correctly.