The invention relates to methods of transmitting information relating to a quality of service, which information is to be transmitted in at least one direction between a first device (30) and a second device (20). A first method comprises at least at one of the devices(20, 30) assembling a protocol message containing information other than the information relating to a quality of service and attaching the quality of service related information to the protocol message. A second method comprises forming the information relating to a quality of service inside at least one of a header field and an attribute of a protocol message. The invention relates equally to corresponding software codes, devices (20, 30), network elements and systems.