WCF is formerly known as the code “Indigo” is the first Unified Programming Model (UPM) for Service Oriented Applications (SOA). It is the unification of the technologies used to deliver distributed systems such as Enterprise Services, Messaging, .NET remoting, ASMX and WSE that run on the Microsoft platform. In other words, Windows Communication Foundation is an advanced technology to provide web services/remoting functionality with better features and reduces the time to develop a distributed system. It makes development interoperable with Non-MS Platform and integrates with existing products. We can build amazing services that would add more weight using WCF. WCF uses SOAP messages for communication between two processes. WCF has a set of API's for creating systems that send messages between services and clients. The same API's are used to create applications that communicate with other applications on the same system or on a system that resides in another company.

Core components

Here is a list of core components in WF.

1. End Point: A WCF service is exposed to the world as a collection of endpoints. It is the point where messages are sent or received. It consists of Address, Binding and Contract.

Address: End point consists of location where message can be sent/received. This is equivalent to a service address in WSDL. An example of Address components are URI, Identity & Headers.

Binding: This is a communication mechanism that describes how messages can be sent. This represents configuration. It is made up of various binding elements like Transport protocol, such as TCP, HTTP, MSMQ, named pipes, Encoding such as text, Message Transmission Optimization Mechanism such as MTOM, binary, and security like asymmetric, symmetric and transport.

Contract: It is a definition for a set of messages that can be sent or received (or both) at the address that describes what message can be sent. It describes the WCF contracts and their operations like One way, request/reply, duplex, and queuing.

2. Channel: A channel is a concrete implementation of a binding element. The channel is the implementation associated with that configuration.

3. Client: A program that exchanges messages with one or more endpoints using channels.

4. Service: A service is a construct that exposes one or more endpoints, with each endpoint exposing one or more service operations.

5. Behavior: A behavior is a component that controls various run-time aspects of a service, an endpoint, a particular operation, or a client.

·         WCF has rich communication capabilities.

·         WCF is 25%—50% faster than ASP.NET Web Services and approximately 25% faster than .NET Remoting.

·         It is secured, Confidential in keeping messages.

·         Using WCF message transfer is reliable.