Apparatus for controlling data traffic and a method for measuring QoE

A method for measuring the Quality of Experience of a data session at a measurement point in a communication system comprising at least one client device and at least one server device interconnected over a packet-switching data link, wherein the method comprises:

• i. capturing at least two first timestamps each specifying a time at which a certain data package or a particular content of said data package has to be processed at the client side;
• ii. capturing at least two second timestamps each specifying a time at which an acknowledgement package sent by the client device for acknowledging said certain data packets is captured;
• and
• iii. determining the Quality of Experience of the data session from said first and second timestamps.

A device for determining the Quality of Experience in a communication system, the device processing in accordance with a method including the following steps:

• i. capturing at least two first timestamps each specifying a time at which a certain data package or a particular content of said data package has to be processed at the client side;
• ii. capturing at least two second timestamps each specifying a time at which an acknowledgement package sent by the client device for acknowledging said certain data packets is captured;
• and
• iii. determining the Quality of Experience of the data session from said first and second timestamps.

A video server for transmitting data streams over a packet based network, comprising:

• a. means for transmitting a first video stream and a second video stream over the packet based network;
• b. means for determining the Quality of Experience of the transmission of the first video stream;
• c. means for comparing the determined Quality of Experience against a predetermined threshold;
• and
• d. means for determining and adjusting the current data rate of the second video stream if the determined Quality of Experience is lower than a predetermined threshold.