A method for use in a Transport Network, TN, in a Radio Access Network, RAN, in an HSPA enabled cellular system. The method includes inspecting and/or queuing data frames which are sent over at least part of the TN between a Radio Network Controller, RNC, and a NodeB in the cellular system, and using the inspected and queued data frames to identify flows in at least part of the TN and to detect congestion in at least part of the TN. The method further comprises taking a congestion control action using identified flows and/or detected congestion in at least part of the TN.