Connecting Web Services and SOA
Web services is a technology that enables SOA. It is not the only technology enabling SOA — there are others such as Common Object Request Broker Architecture (CORBA) and Java Remote Method Invocation (RMI). But, it certainly is the most talked about because it is easier to use and is platform and technology independent.
While SOA defines the business paradigm for implementing a services-based distributed computing solution, Web services is a technology standard that enables it.
“SOA is not just a technology thing. It involves many different aspects of an enterprise, from the skills people have, to the way the organization is set up and right through to how their supply-and-demand chain is established — including technology,” says Terri Bennett Schoenrock, Executive Director, SOA, HP.
Factoring Other Technologies
If Web services is not the only technology available to enable integration and interoperability, and the likes of CORBA, Java RMI and .NET Remoting are available, why then choose Web services?
SOURCE: THE IMPACT BRIEF
The scope of Web services is broader than that of most other technologies. While .NET Remoting can make Microsoft’s Web-based applications talk and Java RMI can do the same with Sun’s applications, Web services is platform and technology agnostic. In layman’s terms, it can make every application talk to the other, which means it can, for example, make Microsoft’s applications talk to Sun’s applications.
“We would always recommend Web services over CORBA, WCF [Windows Communication Foundation] and .NET Remoting,” says HP’s Schoenrock. “There may be some unique cases where a company might consider one of the legacy mechanisms, but it would be a rare exception.”
But, CORBA is also platform and language independent. Then why not CORBA? Communication across CORBA can be blocked by corporate firewalls (technically it uses nonstandard ports for communication). Using CORBA will require companies to be flexible about their firewall setups. This is something that is practically not possible when companies have offices spread across hundreds of locations — zip codes, cities and countries.
Web services communicates with applications in the same way Web browsers (Internet Explorer, Netscape, Opera) communicate with Websites. And since corporate firewall setups do not generally block Web browsing, the chances are that they will not block Web services either.
