+------------------+ 
                          | I2NSF Controller |  
                          +------------------+               
                   I2NSF NSF-Facing |
                          Interface |
                  /-----------------+---------------\
                 /                                   \
                /                                     \ 
   +----+  +--------+                            +--------+  +----+
   | h1 |--| nsf_h1 |== IPsec_ESP_Tunnel_mode == | nsf_h2 |--| h2 |
   +----+  +--------+                            +--------+  +----+
          :1        :100                       :200       :1
          
(2001:db8:1:/64)          (2001:db8:123:/64)       (2001:db8:2:/64)