If your company is ready to begin implementing a true service-oriented architecture, you'll need to consider what technologies are used to enable messaging and message processing, and how to secure those messages as they flow through the network and are retained in memory or on disk.
Web services technology exchanges XML messages among processes. The XML message is contained in an XML envelope defined by the SOAP standard. The ultimate recipient of a message, called a service endpoint, is hosted in a Web service platform (WSP), such as Apache Axis, IBM WebSphere or Microsoft Server System. SOAP messages are transport-independent--that is, a message can be sent over any transport the WSP supports, such as HTTP, SMTP or WebSphere MQ.
Service-oriented architecture (SOA), on the other hand, isn't a technology. Rather, it's an application design that ensures network-accessible services are autonomous and, therefore, easily shared and reused. Although an SOA can be created using a variety of messaging technologies, such as CORBA or RMI, the SOAP messaging standard's openness and broad product support make Web services the most effective choice for creating an SOA. XML messaging and standard message formatting support a central tenet of an SOA: pervasive intermediation. That is, Web service messages can be routed through any number of intermediaries that can analyze and operate on the messages as they flow to the ultimate endpoint.
