+----------+
| SF1      |                 +--------+                  +------+ 
| instance |\                |   NR   |                  | SF2  | 
+----------+ \               +--------+                  +------+ 
              \                  ||                         ||
+------------+ \ +-------+   +---------+   +---------+   +-------+
| Classifier |---| nSFF1 |---|Forwarder|---|Forwarder|---| nSFF2 |    
+------------+   +-------+   +---------+   +---------+   +-------+
                                                            ||
                                                        +----------+ 
                                                        | Boundary |
                                                        |  node    |
                                                        +----------+