+-------------+
  | client      |
  +-------------+                   1..* +-----------------------+
  | admin-state |<>----------------------| mode-preference-chain |
  |             |                        +-----------------------+
  |             |  1..* +------------+   | priority              |
  |             |<>-----| key-chain  |   | mode                  |
  +-------------+       +------------+   +-----------------------+
         ^              | key-id     |
         V              | secret-key |
         |              +------------+
         | 0..*
  +------------------------+
  | ctrl-connection        |
  +------------------------+
  | name                   |
  | client-ip              |
  | server-ip              |
  | server-tcp-port        |    0..* +----------------------+
  | control-packet-dscp    |<>-------| test-session-request |
  | key-id                 |         +----------------------+
  | max-count              |         | name                 |
  | client-tcp-port   {ro} |         | sender-ip            |
  | server-start-time {ro} |         | sender-udp-port      |
  | state             {ro} |         | reflector-ip         |
  | selected-mode     {ro} |         | reflector-udp-port   |
  | token             {ro} |         | timeout              |
  | client-iv         {ro} |         | padding-length       |
  +------------------------+         | test-packet-dscp     |
                                     | start-time           |
              +-------------+ 1      | repeat               |
              | pm-reg-list |------<>| repeat-interval      |
              +-------------+        | state           {ro} |
              | pm-index    |        | sid             {ro} |
              +-------------+        +----------------------+