A Windows Communication Foundation (WCF) service has a callback contract. You are developing a client application that will call this service.
You must ensure that the client application can interact with the WCF service.
What should you do?

• A. On the OperationContractAttribute, set the AsyncPattern property value to True.
• B. On the client, create a proxy derived from DuplexClientBase(Of TChannel).
• C. On the OperationContractAttribute, set the ReplyAction property value to the endpoint address of the client.
• D. On the client, use GetCallbackChannel (Of T).

You are implementing a Windows Communication Foundation (WCF) client application that consumes the ICatalog and lCatalog2 service interfaces
You need to ensure that the client discovers services implementing these interfaces
The services may already be online or may come online within a 30 second time limit
How should you use WCF Discovery to accomplish this?

• A. Create a single FindCriteria object and add both interfaces to its ContractTypeNames
  collection. Set the criteria's Duration to two seconds.
  Create a loop that calls the Find method of the DiscoveryClient class to search for the
  services.
  Within each loop iteration, call the Find method of the DiscoveryClient class to search for
  the services Run the loop until a service is found or 30 seconds pass.
• B. Create a single FindCritera object and add both interfaces to the ContractTypeNames
  collection. Set the Duration to 30 seconds and use the FindAsync method of the
  DiscoveryClient class to search for the services.
• C. Create one FindCriteria object for each interface and set the Duration of each
  FindCriteria to two seconds.
  Create a loop that calls the Find method of the DiscoveryClient class to search for the
  services.
  Within each loop iteration, call the Find method of the DiscoveryClient class once for each
  of the FindCriteria objects Run the loop until a service is found or 30 seconds pass.
• D. Create one FindCriteria object for each interface and set the Duration of each
  FindCriteria to 30 seconds Call the FindAsync method of the DiscoveryClient class twice,
  one time for each of the FindCriteria objects, to search for the services.

The endpoint of a Windows Communication Foundation (WCF) service uses basicHttpBinding for its binding Your Company's policies have changed to require that messages not be sent in clear text.
You must ensure that all messages are encrypted when traveling across the network What should you do?

• A. Set the ProtectionLevelAttribute on the service contract and update the binding attribute in the endpoint element of the configuration file to wsHttpBinding
• B. Set the PrincipalPermissionAttribute on the service contract and update the binding attribute in the endpoint element of the configuration file to wsHttpBinding
• C. Set the PrincipalPermissionAttribute on the service contract and update the bindingConfiguration attribute in the endpoint element of the configuration file to wsHttpBinding.
• D. Set the ProtectionLevelAttribute on the service contract and update the bindingConfiguration attribute in the endpoint element of the configuration file to webHttpBinding

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You are creating a Windows Communication Foundation (WCF) service.
You have the following requirements:
Messages must be sent over TCP.
The service must support transactions.
Messages must be encoded using a binary encoding.
Messages must be secured using Windows stream-based security.
You need to implement a custom binding for the service.
In which order should the binding stack be configured?

• A. tcpTransport windowsStreamSecurity transactionFlow binaryMessageEncoding
• B. binaryMessageEncoding transactionFlow tcpTransport windowsStreamSecurity
• C. transactionFlow binaryMessageEncoding windowsStreamSecurity tcpTransport
• D. windowsStreamSecurity tcpTransport binaryMessageEncoding transactionFlow