DOTS clients       DOTS server
   +---+
   | c |-----------
   +---+           \
   c1.example.org   \
                     \
   +---+              \ +---+
   | c |----------------| S |
   +---+              / +---+
   c1.example.com    /  dots1.example.net
                    /
   +---+           /
   | c |-----------
   +---+
   c2.example.com