WCF Interoperability with Applications Built on Other Technologies And Explicit Support For SOA

Interoperability with Applications Built on Other Technologies

WCF is designed to interoperate well with the non-WCF world i.e. with WCF supports both cross platform communication and with the Microsoft technologies that preceded WCF.

Supported Features

•   Messaging: SOAP is the foundation protocol for Web services, defining a basic envelope containing a header and a body. WS-Addressing defines additions to the SOAP header for addressing SOAP messages, which frees SOAP from relying on the underlying transport protocol, such as HTTP, to carry addressing information. The Message Transmission Optimization Mechanism (MTOM) defines an optimized transmission format for SOAP messages based on the XML-binary Optimized Packaging (XOP) specification.
•   Metadata: The Web Services Description Language (WSDL) defines a standard language for specifying services and various aspects of how those services can be used. WS-Policy allows specification of more dynamic aspects of a service’s behavior that cannot be expressed in WSDL, such as a preferred security option. WS-MetadataExchange allows a client to request descriptive information about a service, such as its WSDL and its policies, via SOAP. Beginning with the .NET Framework 4 release, WCF also supports WSDiscovery. This broadcast-based protocol lets an application find services available elsewhere on its local network.
•   Security: WS-Security, WS-Trust and WS-SecureConversation all define additions to SOAP messages for providing authentication, data integrity, data privacy and other security features.
•   Reliability: WS-ReliableMessaging defines additions to the SOAP header that allow reliable end-to-end communication, even when one or more SOAP intermediaries must be traversed.
•   Transactions: Built on WS-Coordination, WS-AtomicTransaction allows using two-phase commit transactions with SOAP-based exchanges.

WCF implements a range of Web services standards as shown

Explicit Support For Service-Oriented Development.

Creating applications in a service-oriented style is becoming very common with the increasing number of platforms and large applications to work perfectly on all these available platforms. For this, the technology on which those applications are built must provide the right support for creating service-oriented software. Achieving this is one of WCF‟s most important goals.

Thinking of an application as providing and consuming services is hardly a new idea. WCF has a clear focus on services as distinct from objects.

•   Share schema, not class. Unlike older distributed object technologies, services interact with their clients only through a well-defined XML interface. Behaviors such as passing complete classes, methods and all, across service boundaries aren‟t allowed.
•   Services are autonomous. A service and its clients agree on the interface between them, but are otherwise independent. They may be written in different languages, use different runtime environments, such as the CLR and the Java Virtual Machine, execute on different operating systems, and differ in other ways.
•   Boundaries are explicit. A goal of distributed object technologies such as Distributed COM (DCOM) was to make remote objects look as much as possible like local objects. While this approach simplified development in some ways by providing a common programming model, it also hid the inescapable differences between local objects and remote objects. Services avoid this problem by making interactions between services and their clients more explicit. Hiding distribution is not a goal.
•   Policy-based compatibility. When possible, determining which options to use between systems should rely on mechanisms defined in languages such as WSDL and WS-Policy. The ability for a client to consume a service is based on the intersection of what the client supports and what the service supports.

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