A device includes a frame data analyzer that generates buffer increment data based on frame data sent from the media server to the media client and further based on acknowledgement data sent from the media client to the media server. A playback data generator generates playback data based on frame data buffer contents and further based on player state data. A frame buffer model generator generates a buffer fullness indicator and the frame data buffer contents, based on the buffer increment data and the playback data. A player state generator generates the player state data, based on the buffer fullness indicator and further based on media client data, media server data and player command data.