C                            RS                   AS
   | <===== DTLS channel =====> |                     |
   |        + Access Token      |                     |
   |                            |                     |
   | --- Token Request  ----------------------------> |
   |                            |                     |
   | <---------------------------- New Access Token - |
   |                           + Access Information   |
   |                            |                     |
   | --- Update /authz-info --> |                     |
   |     New Access Token       |                     |
   |                            |                     |
   | == Authorized Request ===> |                     |
   |                            |                     |
   | <=== Protected Resource == |                     |