+-----------+                                         +-----------+
|DOTS Client|                                         |DOTS Server|
+-----------+                                         +-----------+
      |                                                     |
   T0 |--DTLS ClientHello, IPv6 ---->X                      |
   T1 |--DTLS ClientHello, IPv4 ---->X                      |
   T2 |--TCP SYN, IPv6-------------->X                      |
   T3 |--TCP SYN, IPv4------------------------------------->|
      |<-TCP SYNACK-----------------------------------------|
      |--TCP ACK------------------------------------------->|
      |<------------Establish TLS Session------------------>|
      |----------------DOTS signal------------------------->|
      |                                                     |

 Note:
  * Retransmission messages are not shown.
  * T1-T0=T2-T1=T3-T2= Connection Attempt Delay.