Items in the Exchange store can be accessed remotely by using the WebDAV protocol, defined in RFC 2518. This protocol extends the HTTP 1.1 protocol, defined by RFC 2616, to provide additional methods and capabilities. It provides a means to access both the contents of an item and an extensible set of associated properties. Some of the methods defined by the protocol are the MOVE Method, the COPY Method, the DELETE Method, and the MKCOL Method. The encoding format used to transfer item properties across the network is XML, defined in the World Wide Web Consortium (W3C) Recommendation REC-xml-20001006.
When a URL in the Exchange store is entered in a Web browser, an XML formatted WebDAV protocol request is created and sent to the Microsoft® Exchange Server computer. When the server receives the request, it verifies the credentials of the client and automatically parses the XML for the requested data. The server then builds an XML WebDAV protocol response containing the appropriate properties and their values and sends the response back to the client. If the Web browser is able to parse XML, an XSL style sheet can be applied to the XML response and the data will be displayed in the browser. If the Web browser cannot parse XML, the information is displayed in HTML.
See Authentication and Security Using WebDAV for more information.
The following illustration shows how a client browser interacts with the Exchange store using WebDAV.
Microsoft Internet Explorer 5 and later provide the Microsoft XML (MSXML) Component Object Model (COM) component, a powerful XML parser and set of related tools. The XMLHTTPRequest COM class integrates with MSXML COM objects to simplify the management of client-side HTTP protocol requests and responses that contain XML bodies. The transformational capabilities of the MSXML component can easily cast the response XML data into HTML, which can then be displayed by the browser.
This section consists of the following topics.