BizTalk: E-Commerce the Microsoft Way I (3/3) - exploring XML | WebReference

BizTalk: E-Commerce the Microsoft Way I (3/3) - exploring XML

BizTalk: E-Commerce the Microsoft Way I

BizTalk Messages

A BizTalk Message is the unit of wire-level interchange between BizTalk Servers. BizTalk Messages are used to send BizTalk Documents, and any related files, between BizTalk Servers. A BizTalk Message must always contain a primary BizTalk Document that defines the semantics of the Message within the BizTalk Framework. It may in addition contain one or more attachments (see below), including well-formed XML documents, some of which may themselves be BizTalk Documents. BizTalk Documents carried as attachments are treated just like any other XML documents and have no special significance for the semantics of the BizTalk Message. The structure of a BizTalk Message is dependent on the transport being used to carry the message and often includes transport-specific headers.

Message Transport

The actual interchange of BizTalk Messages between servers presupposes a communication mechanism that is used to carry Messages physically from the source to the destination business entity. Transports used in this context will vary widely in their characteristics, ranging from simple datagram and file transfer protocols to transfer protocols such as HTTP and SMTP, and sophisticated, message-oriented middleware. This specification does not differentiate between transports based on their capabilities.

Endpoints and Addresses

An endpoint designates a BizTalk Framework compliant source or destination of a BizTalk Message. An address is the location of an endpoint, resolvable in context for the purposes of message transport and delivery.

Attachments

Attachments are generally non-XML files or other related information that is not transmitted as a Business Document within the body of the BizTalk Document. These may be related images, large compressed files, or any other information format or content that is not an appropriate Business Document. Attachments may be carried within the BizTalk Message enclosing the BizTalk Document, or they may be external to the Message, and simply referenced within the Document.

BizTalk specifies the following:

Most Internet transports are capable of transporting MIME encoded content.

Reliable Delivery of BizTalk Documents

BizTalk facilitates asynchronous document exchanges involved in e-commerce and Enterprise Application Integration, where specific delivery guarantees and error detection and reporting are necessary for integration of business functions across domain boundaries. High-performance-messaging middleware solutions for the Internet are emerging and should be used for this purpose when available. However, given the broad scope of deployment scenarios for BizTalk Framework-based application integration, and the continued use of transports with lower guarantees of service, it is important to provide a simple standard solution for reliable delivery of BizTalk Documents that can be easily implemented by BizTalk servers. Furthermore, standard business processes require confirmation not just of delivery and physical acceptance of a message, but also separately of verification of message content and intent to perform the business action requested.

The solution for both these requirements is based on two simple notions:

The overall purpose is to ensure a defined outcome for BizTalk Document delivery, acceptance and processing commitment. The following points summarize the ideas on which the functionality described here is based:

Securing BizTalk Documents and Messages

Business processes very often require the ability to secure individual messages for authentication, integrity, non-repudiation or privacy. Transport-level mechanisms such as Secure Socket Layer (SSL) are sufficient for single-hop privacy and authentication but do not satisfy requirements for signing and encryption of individual messages and message parts for multi-hop transport and routing which is very common in business scenarios. The BizTalk Framework supports S/MIME version 3 for securing BizTalk Messages and their parts.

Conclusion

This would not be a Microsoft framework without a subsequent implementation suite, and BizTalk is no exception: The BizTalk server and the BizTalk.org Web site are an implementation of and a repository for the framework, respectively. We'll look at them in our next article, bye for now!

Acknowledgements: This article contains information from the Microsoft Developer Network (MSDN).

Produced by Michael Claßen

URL: http://www.webreference.com/xml/column47/3.html
Created: Jan 07, 2002
Revised: Jan 07, 2002