Abstract: The present invention concerns a technique for providing Class-of-Service Routing in an ATM network (10) that utilizes the Private Network-Network Interface (PNNI) protocol. An originating node seeking to route a call to a terminating node does so by initially determining the class-of-service and then selecting a shortest length path there-between. Each successive link on the selected path is examined for sufficient available bandwidth and available depth (i.e., bandwidth not reserved for other services) for the Class-of-Service of the call. If every link possesses sufficient available bandwidth, then the call passes on the selected path. Otherwise, should a link on the selected path lack sufficient bandwidth and available depth, then a crankback message is sent to the originating node, and the originating node selects the next shortest path. Thereafter, the process of examining each link for sufficient bandwidth is repeated. If no path is found, the call is ultimately blocked.

Abstract: The present invention concerns a technique for providing Class-of-Service Routing in an ATM network (10) that utilizes the Private Network-Network Interface (PNNI) protocol. An originating node seeking to route a call to a terminating node does so by initially determining the class-of-service and then selecting a shortest length path there-between. Each successive link on the selected path is examined for sufficient available bandwidth and available depth (i.e., bandwidth not reserved for other services) for the Class-of-Service of the call. If every link possesses sufficient available bandwidth, then the call passes on the selected path. Otherwise, should a link on the selected path lack sufficient bandwidth and available depth, then a crankback message is sent to the originating node, and the originating node selects the next shortest path. Thereafter, the process of examining each link for sufficient bandwidth is repeated. If no path is found, the call is ultimately blocked.

Abstract: The priority of the flow of packets representing calls or other connection requests within a packet network (10) is determined from the Class-of-Service of the call. Upon receipt of a call, a recipient router (121, 122, 123) identifies available paths, typically by exchanging messages with the other routers in the network. After selecting the path, the recipient router or centralized bandwidth broker determines whether the links comprising the selected path have available bandwidth for the class of service of the call. If so, the router routes the call to the next hop along the path. Otherwise, the router selects another path(s) and checks whether the links on the path possess sufficient bandwidth for the class of service of the call.

Abstract: An originating switch (110) in a packet-based telecommunications network (100) routes calls to a terminating switch using the combination of Success-to-the Top (STT) and Class-of-Service criterion. In routing a call to the terminating switch, the originating switch 110 checks for available bandwidth for the class of service of the call on the direct path (116) between switches. If the path has available bandwidth, the originating switch routes on the direct path. Otherwise, the originating switch searches for the most recently successful one of a plurality the via switches (1181-118n) linking the originating and terminating switches to determine whether that via switch can successfully route the call to the terminating switch. If the most recently successful one of the via switches possesses available bandwidth to route the call in accordance with its class of service, the originating switch 110 selects that via switch to route the call.

Abstract: The routing of calls in a telecommunications switching system (12.sub.1, 12.sub.2) comprised of one or more fabrics (22.sub.1, 22.sub.2, 22.sub.3) controlled by corresponding fabric controllers (26.sub.1,26.sub.2 and 26.sub.3, respectively) is carried out by a routing processor (28) independent of the fabrics. The routing processor actually selects the route for each call by specifying a channel to a neighboring switching system to carry the call. Further, the routing processor has the capability to respond to queries from other switching systems regarding trunk group status and traffic load to enable the processor to assist the routing processor of the other switching system to make routing decisions. By implementing fabric independent routing, routing processing is re-used for new fabric capacity, and is readily extended to accommodate new service types, such as bursty data services.

Abstract: The routing of calls from one network (100) to another network (170) may be accomplished by tracking the call completion history over each trunk group (174.sub.1 -174.sub.2) connecting the networks. From a knowledge of the call completion history for each route, a Completion Rate Factor (CRF), representing the ratio of completed calls to all calls attempted is computed. The route having the CRF representing the highest number of completions is then selected. Typically, the process is dynamic, so that if the selected route no longer has the highest number of completions, then the route previously found to have the highest number of call completions is selected. The concept of completion rate factor routing can be extended to multiple carriers to yield a carrier completion rate feature routing technique. Routing may also be completed in accordance with network congestion to route advance a call.

Abstract: Local/toll dynamic routing integration is achieved within a telecommunications network (14) that includes at least one dynamic routing local switching system (24-1) for receiving incoming call and a plurality of toll switching systems (27-1 through 27-7) at least one of which is associated with each local switching system. For each incoming call, the local switching system (24-1) derives a set of Class-Of-Service (COS) parameters indicative of the class-of service associated with the call. In accordance with the COS parameters, the local switching system (24-1) determines whether each incoming call is a featured call, requiring routing to the toll switching system associated therewith, or a non-featured call. Featured calls are routed to the toll switching system associated with the local switching system for feature processing, whereas non-featured calls are routed by the local switching system itself in accordance with the COS parameters, thus relieving the load on the associated toll switching system.

Abstract: A telecommunications network (10) includes an Originating Switching System (12.sub.1) and a Terminating Switching System (12.sub.2) linked by a plurality of trunks (20.sub.1 -20.sub.4). For each incoming call it receives, the Originating Switching System establishes a Circuit Selection Capability Indicator (CSCI) value that determines what enhancement, if any, the Originating Switching System will provide to the call. The Originating Switching System also utilizes the CSCI value to select an appropriate trunk that is compatible with a type of call enhancement, if any, to route the call to the Terminating Switching System which also enhances the call in accordance with the CSCI value. Determining the call enhancement in accordance with the CSCI value allows different types of calls which are routed on the same trunk to get different call quality enhancements, depending on the call type.