+---------------------------------+
      |                                 |
      |         DetNet App-Flow         |
      |       (original IP) Packet      |
      |                                 |
      +---------------------------------+ <--\
      |            DetNet ACH           |    |
      +---------------------------------+    +--> PREOF-capable
      |       Service-ID (S-Label)      |    |    DetNet IP data
      +---------------------------------+    |    plane encapsulation
      |            UDP Header           |    |
      +---------------------------------+    |
      |            IP Header            |    |
      +---------------------------------+ <--/
      |            Data-Link            |
      +---------------------------------+
      |             Physical            |
      +---------------------------------+