TURN                                TURN           Peer          Peer
client                              server          A             B
  |                                   |             |             |
  |-- ChannelBind req --------------->|             |             |
  | (Peer A to 0x4001)                |             |             |
  |                                   |             |             |
  |<---------- ChannelBind succ resp -|             |             |
  |                                   |             |             |
  |-- (0x4001) data ----------------->|             |             |
  |                                   |=== data ===>|             |
  |                                   |             |             |
  |                                   |<== data ====|             |
  |<------------------ (0x4001) data -|             |             |
  |                                   |             |             |
  |--- Send ind (Peer A)------------->|             |             |
  |                                   |=== data ===>|             |
  |                                   |             |             |
  |                                   |<== data ====|             |
  |<------------------ (0x4001) data -|             |             |
  |                                   |             |             |