A method (700) for use in a Transport Network, TN, in a Radio Access Network, RAN, in an HSPA enabled cellular system (100). The method (700) comprises (705) inspecting and/or queuing data frames which are sent over at least part of the TN between a Radio Network Controller, RNC (105), and a NodeB (110) in the cellular system (100), and using the inspected and queued data frames to identify flows (710) in said at least part of the TN and to detect congestion (715) in said at least part of the TN. The method (700) further comprises (720) taking a congestion control action using identified flows and/or detected congestion in said at least part of the TN.