SIU should be pre-scheduled because of network delay :
control time
Control time depends on size,delay and channel capacity
requirement of a representative data object.
If the QOP parameters can not meet, the connection can
be denied or use partial dropping.
Multimedia server must keep some data in the buffer.
Client send light-weighted message called feedback
unit periodically to server.
Server use feedback unit to estimate a better actual
playback rate.
Re-synchronization policies are
| conservative | Server reacts only when play-out of different streams is guaranteed to be asynchronous. |
| aggressive | Server reacts as soon as there is even a slight chance that playback is asynchronous. |
| probabilistic | Server reacts on the average |