Abstract: A routing table circuit for a router has one or more input ports and output ports for message communication. In the routing table circuit, one or more routing table memories store a plurality of routing table arrays. The routing table arrays are arranged hierarchically in levels, and each routing table array is associated with a predetermined subset of prefixes. Each routing table array has entries. The entries include a block default route pointer field to store a block default route pointer, if any, and a routing field. The route engine may access any level of table array by using a next level route pointer stored in the routing field. Using the block default route and the routing field, the present invention further reduces the number of memory accesses and the update cost for route insertion and deletion by identifying and skipping elements that do not require route updating.

Abstract: A method of hunting for a communication channel in a communication system where a plurality of communication lines each have a plurality of communication channels includes the steps of maintaining a record of current channel statuses of the communication channels with respect to all the communication lines, and distributing busy channels evenly among the communication lines by selecting a communication channel based on the record of channel statuses and assigning the selected communication channel to a call.

Abstract: Network resources for a call between a calling party and a called party are allocated. The network resources for the call are reserved based on a reservation request. The network resources are reserved before any one network resource from the reserved network resources is committed. The reserved network resources for the call are committed when a called party indicates acceptance for the call.