+-------------------------------------------+
            |                                           |
            | Client               Server      Actuator |
Handshake   |   ----- Q4S BEGIN ----->                  |
            |   <---- Q4S 200 OK -----                  |
            |                                           |
Negotiation |                                           |
(Stage 0)   |   ----- Q4S READY 0---->                  |
            |   <---- Q4S 200 OK -----                  |
            |                                           |
            |   ----- Q4S PING ------>                  |
            |   <---- Q4S 200 OK -----                  |
            |   <---- Q4S PING -------                  |
            |    ---- Q4S 200 OK ---->                  |
            |              ...                          |
            |  (alert-pause start)                      |
            |                          --alert          |
            |                         notification-->   |
            |                                           |
            |                         <--alert          |
            |                          acknowledge---   |
            |                                           |
Repetition  |                                           |
of Stage 0  |   ----- Q4S READY 0---->                  |
            |   <---- Q4S 200 OK -----                  |
            |                                           |
            |   ----- Q4S PING ------>                  |
            |   <---- Q4S 200 OK -----                  |
            |   <---- Q4S PING -------                  |
            |              ...                          |
            |(alert-pause expires &                     |
            |                   violated constraints)   |
            |                                           |
            |                         --alert           |
            |                         notification-->   |
            |                                           |
            |                         <--alert          |
            |                          acknowledge---   |
            |                                           |
            |   ----- Q4S PING ------>                  |
            |   <---- Q4S 200 OK -----                  |
            |   <---- Q4S PING -------                  |
            |              ...                          |
Negotiation |                                           |
(Stage 1)   |   ----- Q4S READY 1---->                  |
            |   <---- Q4S 200 OK -----                  |
            |                                           |
            |   ----- Q4S BWITDH ---->                  |
            |   <---- Q4S BWIDTH------                  |
            |              ...                          |
Continuity  |   ----- Q4S READY 2 --->                  |
            |   <---- Q4S 200 OK -----                  | app start
            |                                           |
            |(alert-pause expires &                     |
            |                  fulfilled constraints)   |
            |                                           |
            |(recovery-pause start)                     |
            |   ----- Q4S PING ------>                  |
            |   <---- Q4S 200 OK -----                  |
            |   <---- Q4S PING -------                  |
            |   ----- Q4S PING ------>                  |
            |                                           |
            |(recovery-pause expires &                  |
            |                  fulfilled constraints)   |
            |                                           |
            |                         --recovery        |
            |                         notification-->   |
            |                                           |
            |                         <--recovery       |
            |                          acknowledge---   |
            |                                           |
            |(recovery-pause start)                     |
            |   <---- Q4S 200 OK -----                  |
            |   <---- Q4S PING -------                  |
            |   ----- Q4S 200 OK ---->                  |
            |   ----- Q4S PING ------>                  |
            |              ...                          |
            |                                           |
Termination |   ----- Q4S CANCEL ---->                  | app end
            |                          --cancel         |
            |                          notification-->  |
            |                                           |
            |                          <--cancel        |
            |                           acknowledge--   |
            |   <---- Q4S CANCEL -----                  |
            |                                           |
            +-------------------------------------------+