Abstract: The present invention relates generally to restoration of services in a network. More particularly, the invention encompasses a scheme for randomized selection of equal cost links during restoration in a communication network. The invention further includes multiple schemes for restoring services. The network could consist of optical, ATM, FR, or IP/MPLS switches and cross-connects.

Abstract: The present invention relates generally to restoration of low priority services in a network. More particularly, the invention encompasses a method and an apparatus for delaying the start of the restoration of low priority services in a communication network. The invention further includes multiple schemes for restoring low priority services. The network could consist of optical, ATM, FR, or IP/MPLS switches and cross-connects.

Abstract: The present invention relates generally to routing of circuits in a network. More particularly, the invention encompasses a method and an apparatus for routing circuits using dynamic self-adjusting link weights within a network. The invention further includes multiple schemes for routing circuits with dynamic self-adjusting link weights in a SCN (Switched Communication Network). The network could consist of optical, ATM, FR, or IP/MPLS switches and cross-connects.

Abstract: A method and a system for allocating restoration capacity in a network link in a communications network provides that a common pool of communication capacity is provisioned in a network link, such that the common pool of communication capacity includes spare capacity for new service and restoration capacity. A pool of pre-allocated communication capacity for future growth of at least one connection in the network link is also provisioned. The pool of pre-allocated communication capacity for future growth is available for restoration capacity, but not for spare capacity for new service. The communications network can be, for example, a private line (PL) network, a SONET-based network, an Asynchronous Transfer Mode (ATM)-based network, an Internet Protocol/MultiProtocol Label Switching (IP/MPLS)-based network or a frame relay (FR)-based network.

Abstract: A method and apparatus is provided for setting up an IP session from a first node, across a network that uses direct virtual path routing, to a second node. The first node receives a request to set up the session. The second node is identified as the destination of the session, based on the request. A first stack of labels is obtained that defines a first path. A second stack of labels is obtained that defines a second path. A first label identifier is selected that identifies the session in a first direction. A second label identifier is selected that identifies the session in a second direction. Finally the data is transmitted from the first node to the second node and from the second node to the first node using the first stack and second stack of labels and label identifiers, respectively.

Abstract: A data network wherein network links have an assigned service weight and a restoration weight that are used as factors for respectively determining an optimum primary data path and a back-up data path through the network. The restoration path is used in the event of a failure of the primary service path and a Dijkstra or similar algorithm may be used for determining these paths. Service weights may be assigned to the links to prioritize finding the shortest possible path, whereas restoration weights may be assigned to the links to find a path with the maximum available capacity.

Abstract: The problems associated with prior solutions for implementing ATM or IP/MPLS in a large-scale network are overcome by providing an efficient means by which capacity in the network is more fully shared without adversely affecting call or session setup latency, and at the same time simplifying network operations. This is achieved by performing the functions of route setup, route allocation, and capacity management in a network at the edges (e.g., the interfaces existing between each ATM switch or IP/MPLS router and customers) of the network. In accordance with the principles disclosed herein, the edges contain nodes that form the interface between the ATM switches and IP/MPLS routers and the link(s) that interconnect them and the outside world. These nodes comprise controllers and other apparatus that in some cases may be incorporated in, or connected as adjuncts to, the ATM switches or IP/MPLS routers.

Abstract: Apparatus for managing packet flow in network routers is provided which communicates the congestion status among the ports inside routers in the network, and substantially eliminates packet dropping due to congestion by providing overflow paths for destination IP addresses. Each router in a network stores at least two possible output paths for selected destination IP addresses, so that the router may direct the output of packets appropriately when congestion is detected on one of the paths. A forwarding table stores the possible output paths for each destination IP address.

Abstract: A method for managing packet flow in network routers is provided which communicates the congestion status among the ports inside routers in the network, and substantially eliminates packet dropping due to congestion by providing overflow paths for destination IP addresses. Each router in a network stores at least two possible output paths for selected destination IP addresses, so that the router may direct the output of packets appropriately when congestion is detected on one of the paths. A forwarding table stores the possible output paths for each destination IP address.

Abstract: A method is provided for setting up a communication from a first edge node, across a network that uses direct virtual path routing, to a second edge node. The first edge node receives a request to set up the communication. The second edge node is identified as the destination of the communication, based on the request. A first virtual path identifier (VPI) is obtained that defines a first path from the first edge node across the network to the second edge node. A second VPI is obtained that defines a second path from the second edge node across the network to the first edge node. The first and second VPIs are selected by a routing status database. A first virtual channel identifier (VCI) within the first VPI is selected. A second virtual channel identifier (VCI) within the second VPI is selected. Data is transmitted from the first edge node to the second edge node using the first VPI and first VCI, and from the second edge node to the first edge node using the second VPI and second VCI.

Abstract: An efficient approach and corresponding apparatus for selecting virtual paths in a network for routing datagrams achieves effective sharing of capacity without adversely affecting call setup latency. Edge nodes of the network assign calls to virtual paths based on the destination of the call and the current load status of each of a relatively small number of paths. Each call is assigned a VPI (Virtual Path Identifier) corresponding to the path chosen and a VCI (Virtual Circuit Identifier) corresponding to the identity of the call at that edge node. The ATM backbone nodes route calls based solely on the VPI. Capacity management and load balancing is achieved by each edge node keeping track of the load on each access link from its edge node to the rest of the network and of the congestion status of the various links in the network.

Abstract: The distribution of replica caches of information is dynamically optimized among the regions of a network, based upon the changing usage patterns. Initially, a single server in a first region stores the primary copy of information. A router in the first region receives service request messages from the plurality of users throughout network, directed to the server storing the primary copy. To determine if it is justified to deploy a replica cache, the router transmits a monitor request message to other routers in other regions of the network, requesting them to monitor all service requests in their respective regions, being directed to the primary copy in the first server. The first router then computes an optimum assignment of a replica copy of the information, for storage in at least one newly assigned server in the network.

Abstract: An efficient approach and corresponding apparatus for selecting virtual paths in a network for routing datagrams achieves effective sharing of capacity without adversely affecting call setup latency. Edge nodes of the network assign calls to virtual paths based on the destination of the call and the current load status of each of a relatively small number of paths. Each call is assigned a VPI (Virtual Path Identifier) corresponding to the path chosen and a VCI (Virtual Circuit Identifier) corresponding to the identity of the call at that edge node. The ATM backbone nodes route calls based solely on the VPI. Capacity management and load balancing is achieved by each edge node keeping track of the load on each access link from its edge node to the rest of the network and of the congestion status of the various links in the network.

Abstract: The call processing capacity of the of a telecommunications network by forming the communication switches forming the network into respective groups of communication switches. The communication switches forming a respective group of switches are fully interconnected to one another and then each of the communications switches forming a respective group is connected at least one other group of telecommunication switches as a way of interconnecting the groups with one another.

Abstract: The efficiency of a telecommunications network is enhanced by associating each of the communication switches forming the network with an external connection control processor and forming the switches into respective groups of communication switches. The communication switches forming a respective group of switches are fully interconnected to one another and then each of the communications switches forming a respective one of the groups is connected at least one other group of telecommunication switches as a way of interconnecting the groups with one another.