examples of events and measurements that can be detected by the streaming client 30 are presented in the table of fig2 while examples of metrics that can be computed by a streaming client 30 or by the streaming server 20 are presented in the table of fig3 it is to be understood that the list of events measurements and metrics employed in the system 10 may differ from the presented ones moreover four ways to define the frequency for transmission of feedback messages from the streaming client 30 to the streaming server 20 comprising events measurements and or metrics are provided in a first periodic alternative the feedback messages are sent during a session according to a certain schedule this provides the possibility of a server action to adjust the qos of the transmitted media stream s if required depending on the frequency defined this may cause some extra traffic in the uplink direction if the period of reporting is too short in a second event based alternative the feedback messages are sent based on the occurrence of events in the client 30 this method also provides possibilities for server 20 to take an action during the session if required if the event rate is high too much extra traffic may be caused in the uplink direction unless many events are appended in to the same message.