Abstract: A switch that makes it possible in real-time to determine paths that are suitable for interconnecting line termination functional entities of couplers. The switch includes a centralization device capable of centralizing information concerning the state of all the line termination functional entity situated in the couplers and a centralization device common to all couplers of the switch to centralize, in particular, all of the information centralized by the first centralizing device. Additionally, the switch is capable of establishing a routing table listing all of the active paths existing between frame relaying line termination functional entities. The switch is particularly applicable to distributors for frame relaying links.

Abstract: A type of switching fabric for exchanging variable-size frames of digital information between frame processors coupled directly or indirectly to one or more digital communication lines. It comprises one or more multi-line serial communication controllers (MSCCs), and a backplane providing a full mesh of serial point-to-point bi-directional links between each MSCC, and, in a loopback, from each MSCC back to itself. The MSCCs collectively manage the transfer of variable-size frames between the frame processors. To transfer digital information from a source line to a destination line, a frame processor coupled to the ingress line drives the switching fabric by signaling its MSCC that there is information. The ingress MSCC then switches the digital information through the backplane to the MSCC serving the frame processor coupled to the egress line. The switching fabric uses a clocking scheme that makes possible high throughput rates.

Abstract: In a packet switching (packet-based) network, such as a frame relay (FR) network, which includes network resources made up of networked elements and customer premises equipment interconnected by one or more physical paths, a Virtual Private Network (VPN) is built above the underlying packet-based network and includes selected portions of the packet-based network resources. The VPN is a collection of logical nodes and virtual paths (VPs) and includes one or more virtual circuits (VCs), each VC being a logical connection between VC terminators including network elements and customer premises equipment. Segments of the VCs are carried by VPs, each VP being a logical connection established between two VP terminators which are located in either network elements or customer premises equipment. One or more VPs are multiplexed on a physical path (PP). Each VP is allocated a positive guaranteed bandwidth (VP-CIR), and each VC on a VP is also allocated a bandwidth (VC-CIR) greater than or equal to zero.

Abstract: Connectivity matrix-based multi-cost routing includes defining a generally additive operator which is able to add traditionally (arithmetic) additive cost factors and which takes into account cost factors which are not additive, the generally additive operator being defined such that distributive and communicative properties are applicable, and wherein the generally additive operator is applicable to connectivity matrix-based factors for determining the relative costs of paths within a network, particularly with respect to multi-cost factors. Connectivity matrix-based multi-cost routing is performed by first defining cost functions and establishing a criteria for prioritizing cost functions such that a composite multi-cost function includes the cost functions in the priority order defined by the criterion.

Abstract: In a packet-based communications network (100), a virtual connection is established between a source node (102a) and a destination node (102b), which may traverse one or more intermediate nodes (105). During the flow of packets along the virtual connection in a forward direction, from the source node (102a) to the destination node (102b), each node measures the utilization of critical resources (CUF), and this utilization information is inserted into return packets flowing in the backward (return) direction, from the destination node (102b) to the source node (102b). CUF is indicative of the maximum utilization of any resource in the virtual connection forward path. If the network utilization information indicates that the resources of a virtual connection are under-utilized, the submission rate (SIR) of packets onto the virtual connection is increased.