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 advance web technologies wcf web services

  
   
   

WCF Web Services:

According To MSDN "Windows Communication Foundation (WCF) is a framework for building service-oriented applications. Using WCF, you can send data as asynchronous messages from one service endpoint to another. A service endpoint can be part of a continuously available service hosted by IIS, or it can be a service hosted in an application."

EndPoint

WCF Service is a program that exposes a collection of Endpoints. Each Endpoint is a portal for communicating with the world.

All the WCF communications are take place through end point. End point consists of three components.

Address

Basically URL, specifies where this WCF service is hosted .Client will use this url to connect to the service. e.g

http://localhost:8090/MyService/SimpleCalculator.svc

Binding

Binding will describes how client will communicate with service. There are different protocols available for the WCF to communicate to the Client. You can mention the protocol type based on your requirements.

A binding has several characteristics, including the following:

  • Transport -Defines the base protocol to be used like HTTP, Named Pipes, TCP, and MSMQ are some type of protocols.
  • Encoding (Optional) - Three types of encoding are available-Text, Binary, or Message Transmission Optimization Mechanism (MTOM). MTOM is an interoperable message format that allows the effective transmission of attachments or large messages (greater than 64K).
  • Protocol(Optional) - Defines information to be used in the binding such as Security, transaction or reliable messaging capability

The following table gives some list of protocols supported by WCF binding.

Binding Description
BasicHttpBinding Basic Web service communication. No security by default
WSHttpBinding Web services with WS-* support. Supports transactions
WSDualHttpBinding Web services with duplex contract and transaction support
WSFederationHttpBinding Web services with federated security. Supports transactions
MsmqIntegrationBinding Communication directly with MSMQ applications. Supports transactions
NetMsmqBinding Communication between WCF applications by using queuing. Supports transactions
NetNamedPipeBinding Communication between WCF applications on same computer. Supports duplex contracts and transactions
NetPeerTcpBinding Communication between computers across peer-to-peer services. Supports duplex contracts
NetTcpBinding Communication between WCF applications across computers. Supports duplex contracts and transactions

Contract

Collection of operation that specifies what the endpoint will communicate with outside world. Usually name of the Interface will be mentioned in the Contract, so the client application will be aware of the operations which are exposed to the client. Each operation is a simple exchange pattern such as one-way, duplex and request/reply.

Below figure illustrate the functions of Endpoint