+------------------------ DC2 ----------------------+ 
                   |                         +-----+                   |
                   |                         | SF2 |                   |
                   |                         +--+--+                   |
                   |                            |                      |
                   |                            |                      |
                   |        +------------+      |    +------------+    |
                   |        | N(100,254) |      |    | N(100,253) |    |
                   |        +------------+      |    +------------+    |
                   |        | F:Inner Pkt|      |    | F:Inner Pkt|    |
                   |        +------------+  ^   |  | +------------+    |
                   |                    (7) |   |  | (8)               |
                   |                        |   |  v                   |
             (5)   |                 (6)        |     (9)              |
+---------+  --->  | +----------+   ---->    +--+---+ ---->            |
|         |   SR   | |          |    NSH     |      |  IP              |
+ DC1-GW1 +--------|-+ DC2-GW1  +------------+ SFF2 |                  |
|         |        | |          |            |      |                  |
+---------+        | +----------+            +------+                  |
                   |                                                   |
                   |           +------------+      +------------+      |
                   |           | N(100,254) |      | F:Inner Pkt|      |
                   |           +------------+      +------------+      |
                   |           | F:Inner Pkt|                          |
                   |           +------------+                          |
                   +---------------------------------------------------+