Describe the WCF architecture

WCF is built on top of .NET 2.0 Framework. You can see WCF as a set of classes that allows developers to build service-oriented applications. The architecture of WCF is layered.

It mainly consist of 4 Layers i.e contracts, Service runtime, Messaging, and Activation and hosting.

1. Contract Layer: There are 4 types of contracts available in WCF.

• Service Contract
• Data Contract
• Message Contract
• Policies and Bindings

2. Service runtime: There are 5 different types of service runtime behaviors available in WCF, They are

• Throttling Behavior
• Error Behavior
• Metadata Behavior
• Instance Behavior
• Transaction Behavior
• Dispatch Behavior

3. Messaging: This layer defines the formats and data exchange during service communication. There are 2 types of messaging channels are available:

• Transport Channels
• Protocol Channels

4. Activation and hosting: You can host WCF applications in multiples ways some of them are

• Self-hosting
• IIS hosting
• WAS hosting
• Windows service hosting