+-----------------+     +-------------------+ 
  |     Routing     |     |  OAM  Control     |   
  +-----------------+     +-------------------+  
  
  
                                          Controller Plane    
+-+-+-+-+-+-+-+-+ Southbound Interface -+-+-+-+-+-+-+-+-+-+-+-+
                                           Network Plane   
                                
                                                |                    
                Operational Plane               .   Data Plane        
                                                |
  +-----------------+                           .
  |  Orientation    |                           |
  +-----------------+                           .
                                                |
  +-----------------+   +-------------------+   .
  |    Point of     |   |  OAM  Maintenance |   |
  |   local Repair  |   |  End Point  (MEP) |   .
  +-----------------+   +-------------------+   |
                                                .
                                                |