The following behaviors are included in the WCF Service Runtime layer.. 

1. Throttling behavior 
Throttling behavior provides the options to limit how many instances or sessions are created at the application level. 

2. Error behavior 
By implementing IErrorHandler interface WCF allows an implementer to control the fault message returned to the caller and also it performs custom error processing such as logging 

3. Metadata behavior 
Through the metadata behavior we can publish metadata of the service by configuring an endpoint to expose the IMetadataExchange contract as an implementation of a WS-MetadataExchange (MEX) protocol. By default it is disabled. 

4. Instance behavior 
This behavior specifies how many instance of the service has to be created while running WCF. 

5. Transaction behavior 
This is used to enables the rollback of transacted operations if a failure occurs. 

6. Dispatch behavior 
This behavior controls how a message is processed by the WCF Infrastructure. 

7. Concurrency behavior 
Concurrency behavior measures how many tasks can be performed simultaneously 

9. Parameter Filtering 
This demonstrates how to validate the parameters passed to a method before it is invoked.