+------------------------------------------------------------------+
 |        Neighboring policy and resource management systems        |
 |                                                                  |
 |   +-------------+   +-----------+   +---------+   +----------+   |
 |   | AAA Server  |   |DHCP Server|   |   EMS   |   |   MANO   |   |
 |   +-------------+   +-----------+   +---------+   +----------+   |
 +------------------------------------------------------------------+

 +------------------------------------------------------------------+
 |                       CU-separated BNG system                    |
 | +--------------------------------------------------------------+ |
 | |   +----------+  +----------+ +------++------++-----------+   | |
 | |   | Address  |  |Subscriber| | AAA  ||Access||    UP     |   | |
 | |   |management|  |management| |      || mgt  ||management |   | |
 | |   +----------+  +----------+ +------++------++-----------+   | |
 | |                              CP                              | |
 | +--------------------------------------------------------------+ |
 |                                                                  |
 |                                                                  |
 |                                                                  |
 | +---------------------------+      +--------------------------+  |
 | |  +------------------+     |      |  +------------------+    |  |
 | |  | Routing control  |     |      |  | Routing control  |    |  |
 | |  +------------------+     | ...  |  +------------------+    |  |
 | |  +------------------+     |      |  +------------------+    |  |
 | |  |Forwarding engine |     |      |  |Forwarding engine |    |  |
 | |  +------------------+  UP |      |  +------------------+  UP|  |
 | +---------------------------+      +--------------------------+  |
+------------------------------------------------------------------+