The present invention concerns a method of configuring quality parameters in a packet-based transmission flow for packets within the flow, and still further a method of transmitting packet-based transmission flows comprising packets of configured quality classes within a session capable of handling at least two distinguishable flows, the method comprising the steps of: receiving packets of a first flow as a first flow of the session, analyzing the received packets in terms of the configured quality classes, separating those segments of the packets of a configured quality class, which configured quality class differs from a quality class of said first flow of the session. Also, a corresponding reception method is disclosed, and respective transmitter and receiver devices are disclosed.