a new method of processing asynchronous transfer mode signaling messages is described wherein a plurality of computing units , each running signaling processing software , collectively provide signaling processing services for all the ports of a switch . as more ports , and more cards , are added to a switch , cus can be incrementally added to support additional traffic . more significantly , in order to optimize the utilization rates of the plurality of cus , the method provides for dynamic load - sharing of signaling traffic between cus , such that a cu is allocated not on a per port basis , but on a per switched virtual circuit session basis .