Phone A        Openser        Asterisk        Openser        Phone B
  |               |               |              |              |
  |               |               |              |              |
  |-- Invite B -->|               |              |              |
  |               |-- Invite B -->|              |              |
  |               |               |              |              |
  |               |               |- Invite B -->|              |
  |               |               |              |              |
  |               |               |              |- Invite B -->|
  |               |               |              |              |
  |               |               |              |<---- OK -----|
  |               |               |              |              | 
  |               |               |<---- OK -----|              |
  |               |               |              |              |
  |               |<---- OK ------|              |              |
  |               |               |              |              | 
  |<---- OK ------|               |              |              |
  |               |               |              |              |
  |---- ACK ----->|               |              |              | 
  |               |               |              |              |
  |               |---- ACK ----->|              |              |
  |               |               |              |              | 
  |               |               |---- ACK ---->|              |
  |               |               |              |              |
  |               |               |              |---- ACK ---->| 
  |               |               |              |              |
	
        ....   reinvites for native bridging (they work) .....
  
  |               |               |              |<---- BYE ----|
  |               |               |              |              | 
  |               |               |<---- BYE ----|              |
  |               |               |              |              |
  |               |               |----- OK ---->|              |   
  |               |               |              |              |
  |               |<-- Invite A --|              |----- OK ---->| 
  |               |               |              |              |
  |<-- Invite A --|               |              |              |
  |               |               |              |              | 
  |---- OK ------>|               |              |              |
  |               |               |              |              |
  |               |---- OK ------>|              |              | 
  |               |               |              |              |
  |<-------------ACK -------------|              |              | 
  |               |               |              |              |
  |               |               |              |              |
  |---- OK ------>|               |              |              |
  |               |               |              |              |
  |               |---- OK ------>|              |              | 
  |               |               |              |              |
  |<-------------ACK -------------|              |              | 
  |               |               |              |              |  
  |<------------ BYE -------------|              |              | 
  |               |               |              |              | 
  |---- OK ------>|               |              |              |
  |               |               |              |              |
  |               |---- OK ------>|              |              | 
  |               |               |              |              |
  |<-------------ACK -------------|              |              | 
  |               |               |              |              |  
  |<------------ BYE -------------|              |              | 
  |               |               |              |              | 
  |---- OK ------>|               |              |              |
  |               |               |              |              |
  |               |---- OK ------>|              |              | 
  |               |               |              |              |
  |<-------------ACK -------------|              |              | 
  |               |               |              |              |  
  |<------------ BYE -------------|              |              | 
  |               |               |              |              |