+---------------------------------------------------------+
|                                                         |
|           LOCAL                        EXTERNAL         |
|   +-------------------+        +-------------------+    |
|   |      +----------+ |        |      +----------+ |    |
|   |      |          | |     +-------->|          | |    |
|   |----->|          | |     |  |      |          | |    |
|   |      |          | |     +--|      |          | |    |
|   |      +----------+ |        |      +----------+ |    |
|   +-------------------+        +-------------------+    |
|                                                         |
|                                                         |
|   +-------------------+        +-------------------+    |
|   |      +----------+ |        |      +----------+ |    |
|   |      |          | |     +---------|          | |    |
|   |<-----|          | |     |  |      |          | |    |
|   |      |          | |     +->|      |          | |    |
|   |      +----------+ |        |      +----------+ |    |
|   +-------------------+        +-------------------+    |
|                                                         |
+---------------------------------------------------------+
