Abstract

A cell routing method and apparatus in an ATM processing apparatus. The ATM processing apparatus has two or more routing tables associated with address filters of an ATM switch to store routing information for indicating the destination of cell output, and two or more conversion tables associated with VPI conversion circuits for replacing VPI (Virtual Path Identifier) or VCI conversion circuits for replacing VCI (Virtual Channel Identifier) to store information for indicating the VPI or VCI obtained after conversion. In an input interface circuit, selection information indicating which routing table and conversion table out of the above described two or more routing tables and two or more conversion tables should be selected is written into an occupied area within a cell. In a switch circuit, the selection information is read and one routing table is selected out of the above described two or more routing tables on the basis of the selection information thus read, and cell routing is thus performed based on information in the selected routing table. Further, in an output interface circuit, selection information contained in the cell is read and one conversion table is selected out of the above described two or more conversion tables on the basis of the selection information thus read, and VPI conversion or VCI conversion is thus executed based on information in the selected conversion table.