The application places an audio/video call to the designated target, after initializing the platform and endpoints. After the call is connected, the application waits for the configuration of the AudioVideoFlowto change. After the configuration of the flow is changed, the application prints the content of the change to the console, and then exits, performing normal platform shutdown.

• Subscribing to a change in flow properties and dealing with being placed on hold.
  
  
• Basic audio/video call placement.
  
  
• AudioVideoFlowhandling and control.
  
  
• Changing the configuration of an active AudioVideoFlow.
  
  

• Microsoft Office Communications Server 2007 R2.
  
  
• Two users capable of sending and receiving audio calls.
  
  
• The credentials for each user, and a client capable of signing in to Office Communications Server.
  
  
• A client signed in to Office Communications Server.
  
  

1. Replace the credentials in the variables at the beginning of the code sample with the credentials and server of the users from your Office Communications Server topology.
   
   
2. Substitute the address of the called user in the code sample with the address of a valid, currently signed-in user capable of receiving audio calls.
   
   
3. Open the project in Microsoft Visual Studio, and then press F5.