Binding         Binding
+--------+  request  +---+  request  +--------+
|  STUN  |<----------| N |<----------|  STUN  |
| server |           | A |           | client |
|        |---------->| T |---------->|        |
+--------+  Binding  +---+ Binding   +--------+
            response       response    |
                                       | reflexive transport address
                                       | & internal transport address
                                       v
                                     +--------+
                                     |  DOTS  |
                                     | client |
                                     +--------+