Methods of transmitting information relating to a quality of service are shown, 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 disclosure relates equally to corresponding software codes, devices 20, 30, network elements and systems.