+
|             ------- uplink ------>
|                                       _    ,--,_
|   +--------+       +------------+   _(  `'      )_    +--------+
+---+   PD   |-------| Delegating |--(   Operator   )---| DHCPv6 |
|   | Client |       |    relay   |   `(_ Network_)'    | server |
|   +--------+       +----------- +      `--'`---'      +--------+
|
|             <----- downlink ------
+                 (client facing)
Client
Network