Abstract: The principle object of the present invention, is to provide flexibility in the routing functions performed in the switching system. Another object is to provide a router that can be centralized in a host computer or distributed among various switching nodes. The router is easily programmable by the system operator to provide different routing algorithms for various calls. The router can be used in a system with a single switching node. However, it is particularly adopted for use in a multiple-switching-node system, either as a central, host resident unit, or as a distributed router resident on the switching nodes. A router embodying the invention uses router tables that are readily configurable by the system operator to route calls based on predefined routing criterion in the incoming or outgoing call.

Abstract: The system includes switching nodes with multiple ports for node-host communication, each port thereby connects the switching nodes to one or more hosts. One of the ports in a switching node is designated as a primary or master port and it connects the switching node to a default host. The default host controls all ports in the switching node and because applications on the default port are given the highest priority during switching node processing, the default host is useful for applications that require instant response from the switch. The other ports in the switching node are secondary ports and they connect the switching node to one or more secondary hosts simultaneously. The applications on the secondary hosts are given a lower priority than the default host's application. Therefore, the secondary hosts are useful for applications that do not require instant response from the switching nodes.