hardware components but are rather dynamically configured in ram as needed the number of fifos created depends on the number of vcs being handled by the particular slot controller according to the invention when a cell is inspected by the cell processor 22 to determine the vci of the cell a fifo is created for that vc if one does not already exist typically each vc fifo would be a 64 k fifo although fifos of different sizes could be used depending on the number of cells expected for a particular vc the arbitration fifos are preferably also dynamically configured in ram the number of arbitration fifos corresponds to the number of priority levels for vcs through the switch as shown in fig3 there are four arbitration fifos representing the current atm priority levels of u201c 0 u201d through u201c 3 u201d u201c 0 u201d being the highest priority in the presently preferred embodiment a separate set of arbitration fifos is used for each switch fabric thus as shown in fig3 fifos 32 a 32 d would be use for switch fabric 14 fig1 and fifos 32 u2032 a 32 u2032 d would be listed for switch fabric 14 u2032 the oam fifos 34 a u2032 34 d are also prefer ably dynamically configured in ram the number of oam fifos corresponds to.