A system and method for communicating elements of information between an access node and a core node of a network. An access node includes a user/network interface, and a core network node includes a cell filtering unit. The UNI includes a measuring unit which measures the actual momentary bit rate of a connection between the UNI and the core node. The UNI also includes a priority level computing unit that computes the priority level of each cell using the measured bit rate and an established nominal bit rate (NBR). The value of NBR represents an expected, but not guaranteed, bit rate associated with a particular user or connection. The connection may be a real-time or a non-real-time connection. A scheduling unit of a node accepts or discards an arriving cell based on the occupancy of a real-time buffer and a non-real-time buffer provided at the node. Cells accepted by the scheduling unit are transferred to either the real-time buffer or the non-real-time buffer depending on cell type. In general, cells are transferred out of the real-time buffer in preference to cells in the non-real-time buffer. In an alternative embodiment, a UNI may include two bit rate measuring units for measuring a short-term and a long-term bit rate of the connection. The priority level computing unit then computes cell priority values using the NBR and the short-term and long-term actual bit rates.