XML Messaging Framework

Realizing the cart can't go before the horse, Microsoft Corp. has developed a comprehensive set of proposed standards about how to use XML

Realizing the cart cant go before the horse, Microsoft Corp. has developed a comprehensive set of proposed standards about how to use XML to send and receive business-to-business messages online.

The BizTalk Framework 2.0 specification, released in December, updates its 1.0 predecessor adding ways to check for reliable message delivery, and it includes information on how to use MIME (Multipurpose Internet Mail Extension) and Secure MIME to securely send BizTalk-based Extensible Markup Language messages over e-mail. HTTP delivery of messages is also described in detail.

Another big change is that BizTalk Framework has been redesigned to conform to Simple Object Access Protocol 1.1 and XML Schema standards proposals. (It also includes XML tags described using the older, nonstandard XML-Data Reduced format.)

Its possible that vendors other than Microsoft will support the BizTalk messaging framework and thus allow interoperability between Microsofts own BizTalk Server and non-Microsoft products. Its too soon to tell if this will happen, though.

BizTalk Server itself has not caught up to the XML standards that BizTalk Framework relies upon, as BizTalk Server uses XML-Data Reduced-formatted messages internally, not XML Schema (though a separate command-line tool is provided with BizTalk Server to convert XML-Data Reduced-formatted messages to an XML Schema format).

The specifics of BizTalk Framework are fairly simple because they describe only the BizTalk message envelope and message characteristics. The items described are sender and receiver names, unique message identifier, time stamps indicating when a message was sent and will expire, topic, request for confirmation of message delivery, request for confirmation of message processing commitment, attachment data, and optional business-specific message information.

Although synchronous communications like HTTP are supported, the specification is clearly oriented toward asynchronous technologies such as e-mail or message queuing (Windows 2000 has message-queuing services built into the operating system). Parts of the specification outline how companies can specify what happens to messages sent or received more than once, as well as a system of time stamps and receipts designed to accommodate slow delivery technologies.

The format of the BizTalk message body is specific to the messages purpose (for example, a purchase order) and industry segment. Microsofts www.biztalk.org Web site has about 450 such message body formats for industries such as architecture, medicine and human resources.