Abstract: The route calculated by the routing portion of a connection-oriented protocol between source and destination nodes is further optimized after it is initially calculated. A node X that is part of the calculated route receives or generates a connection setup request which contains the calculated route. In response to the setup request, node X examines the nodes in the calculated route to determine if node X knows of a direct link between itself and another node Y in the calculated route that is not adjacent to node X. If such a direct link is known by node X to node Y, then node X replaces that portion of the calculated route from node X to node Y with the known direct link in the connection setup request, and then forwards the connection setup request to the next node in the present calculated route, where the optimization algorithm may be performed again.

Abstract: Multiple virtual routing networks having the same identifier are defined on a shared access transport facility network. Virtual connections are defined from some or all of the network nodes to at least one of the virtual routing networks. A virtual connection contains a medium address for the node to which it is connected. When a route is calculated between a source node and a destination node, the identical identifier representing different virtual routing networks may appear in the calculated route. If it does, all portions of the route after the first occurrence up to and including the last occurrence of the identifier in the calculated route is deleted to achieve the optimal route. A destination node address is obtained from storage that is associated with the virtual connection to the destination node and information can then be directly routed to the destination node address via the calculated route in an efficient manner.

Abstract: A method and apparatus for interconnecting first and second networks that use the same protocols for communications by a third network. The third network is defined in the first and second networks as a single virtual communications link of the native type used by the first and second networks. In response to requests from initiating nodes in the first and second networks to communicate with destination nodes in the other of the first and second networks, routing computation services in the first and second networks compute routes through the first and second networks that will connect the originating and destination nodes and that include the virtual link as such a route. The virtual link is also used to remotely support the communication needs of dependent nodes in the first and second networks that do not have the ability to establish communications sessions within the networks on their own.

Abstract: A secure network data communication technique that allows the designation of selected network nodes to share encryption keys with other selected network nodes. A message originating node determines nodes along a message route with which it shares encryption keys. One of these keys is selected and a message is encrypted with the key. The identity of the originating node and the decrypting node that also knows the selected key is added to the encrypted message in clear form. The decrypting node receives the message, recognizes its identity in the message and decrypts the message using the key shared with the originating node. If it is also not the destination node, it repeats the process of selecting a new encrypting node with which it shares a key, re-encrypting and transmitting re-encrypted message toward the destination.