A radio base station (104) is described herein that uses a delay reference timing (DRT) extension (402) located within a received high-speed downlink shared channel (HS-DSCH) data frame (110) to detect a buffering delay that is caused by large buffer build ups in transport nodes (112 and 114) that are located on a transport link (106) between a radio network controller (102) and the radio base station (104). In addition, the radio base station (104) can correct a problem if the detected buffering delay is too long 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).