Abstract: A method for optimizing an established call routed across a network from an originating exchange to a destination exchange over a first connection path. The first connection path features a path metric of interest, such as administrative weight. A second connection path is identified which features an improved path metric, the path is made operative and the call is directed over the second connection path. Thereafter, the first connection path may be dismantled. The second connection path is preferably identified by signalling a call set-up message over the network, wherein the message incorporates a reporting field and each transiting exchange propagating the message updates the reporting field until it specifies the path metric of the replacement connection path traversed by the call set-up message. A connect message incorporating the reporting field back is signalled back to the originating exchange from the destination exchange.

Abstract: A virtual circuit whose path across a network is specified by a human operator (hereinafter operator directed route or ODR VC) is established by manually provisioning a preferred path for the connection, including a source node, destination node, and intermediate nodes or subnetworks therebetween. The source node creates a call setup message which is signalled along the preferred path, whereby the intermediate nodes along the preferred path establish the bearer channel cross-connects. The operator also specifies a re-muting scheme for the ODR VC in the event the preferred path is blocked or a link subsequently fails. The re-routing scheme includes one of (a) the preferred path only; (b) at least one manually provisioned alternate path; and (c) any available path.

Abstract: The invention provides a system and method of a selecting an egress connection from egress connections at a node for a call being established in a network along a path being associated with the node. Each connection has sufficient bandwidth to carry the call and terminates at a same destination point in said path. The system and method comprise utilizing at least a bandwidth load balance value for each connection in a set of the connections to select the egress connection from the set. An administrative factor score may be used to further define members of the set.

Abstract: The present invention provides a system and method of calculating a service disruption in a communication network comprising network elements, including nodes connected via links and at least one originating node. Each node is able to detect a failure in an adjacent network element. Upon detection of a failure, a first timestamp is generated. The detecting node generates a release signal which is transmitted, together with the first timestamp, to an originating node which releases the affected connection. The originating node establishes a new connection and initiates a new call. Upon establishing a new connection, a node affected by the failure, which forms a part of the new connection, records a second timestamp. The second timestamp is chosen to reflect, as closely as possible, the actual time of restoration of service in the network. Service disruption is measured as a difference between the first and second timestamps.

Abstract: A method is disclosed for establishing a switched virtual circuit in a digital network having network nodes with static routing tables. The static routing tables contain at least primary and alternate routing data. When a node is unable to forward a call over its outgoing primary route due to congestion or physical failure and its alternate route is the same as the route on which a call setup request arrived, it clears the call at that node and sends a crankback message to the preceding node, which responds to the crankback message to attempt to dynamically re-route the call over the alternate route stored in the routing table of the preceding node. If the attempt is unsuccessful, it sends the message back to the next preceding node and so on.

Abstract: In source routed or hop-by-hop routed protocol communication networks, when congestion is detected at a certain network element, a notification message is sent to nodes. The nodes keep track of congestion condition and generally have knowledge of the congestion, thereby allowing them to make more intelligent routing decisions, i.e., rate controlling messages, routing traffic around congestion, regulating admission at the edge of the network. The intelligent routing decision is based on the congestion condition indicated by a restriction level which is periodically and dynamically updated.

Abstract: A method of signalling a message using a terminal address across multiple network entities is provided. At least two contiguous network entities are associated with addressing spaces for which message addresses are not routable by way of the terminal address and are not otherwise routable by way of a single address. The method stores a terminal address of either an originating or terminating network entity. At every network border between any two contiguous network entities wherein an immediately succeeding network entity does not provide an address through which the message is routable, it is determined whether the address is to be stored and replaced with another address. If so, the address is stored so as to permit its subsequent retrieval. Once the address has been stored, the another address is assigned to be the address and the message is routed in the succeeding network using the another address.

Abstract: There is provided a method of signalling a message using a terminal address across multiple network entities. At least two contiguous network entities are associated with addressing spaces for which message addresses are not routable by way of the terminal address and are not otherwise routable by way of a single address. At every network border between any two contiguous network entities wherein an immediately succeeding network entity does not provide an addressing space through which the message is routable, it is determined whether the party number is to be stored and replaced with a new party number. If so, the party number is stored so as to permit its subsequent retrieval according to a last-in and first-out precedence to thereby create a stored party number. Once the party number has been stored, a replacement address is assigned as the party number. Also at every such border, it is determined whether the party number is to be discarded and replaced with a stored party number.

Abstract: A method is disclosed for establishing a switched virtual circuit in a digital network having network nodes with static routing tables. The static routing tables contain at least primary and alternate routing data. When a node is unable to forward a call over its outgoing primary route due to congestion or physical failure and its alternate route is the same as the route on which a call setup request arrived, it clears the call at that node and sends a crankback message to the preceding node, which responds to the crankback message to attempt to dynamically re-route the call over the alternate route stored in the routing table of the preceding node. If the attempt is unsuccessful, it sends the message back to the next preceding node and so on.

Abstract: A method is disclosed for establishing a switched virtual circuit in a digital network having network nodes with static routing tables. The static routing tables contain at least primary and alternate routing data. When a node is unable to forward a call over its outgoing primary route due to congestion or physical failure and its alternate route is the same as the route on which a call setup request arrived, it clears the call at that node and sends a crankback message to the preceding node, which responds to the crankback message to attempt to dynamically re-route the call over the alternate route stored in the routing table of the preceding node. If the attempt is unsuccessful, it sends the message back to the next preceding node and so on.