A radio base station (104) is described herein that measures a round-trip-time (RTT) which is the time it takes an uplink (UL) control frame (109a) to travel to a radio network controller (102)) and a downlink (DL) control frame (109b) to travel back from the radio network controller (102). If the measured RTT is greater than a predetermined threshold, then the radio base station (104) can correct a problem associated with too long of a RTT by reducing the bit rate of a certain high-speed (HS) user flow or by reducing the maximum bit rate for all of the HS traffic which is going to be sent by the radio network controller (102) over the transport link (106) to the radio base station (104.