..........                   
       .  +--+  .      
 +--------|C1|--------+                
 |     .  +--+  .     |      
 |     .        .     |    
+--+   .  +--+  .   +--+
|S2|------|C3|------|S1|
+--+   .  +--+  .   +--+
 |     .        .     |    
 |     .  +--+  .     |     
 +--------|C2|--------+     
       .  +--+  .
       '........'    
      DOTS Client 
        Domain