Abstract: A path calculation order determining method executed by a calculating apparatus for calculating a shortest path between a node pair in a network, using information on calculated shortest paths between other node pairs, the method including: a step storing calculated shortest path group information on shortest path groups each including calculated shortest paths from a starting node to one or more terminating nodes except the starting node, and topology information of the network, in a memory medium; and a calculation step of calculating shortest paths, starting from its starting node other than the starting node on the calculated shortest paths and having the most nodes that are located downstream therefrom, and terminating at nodes other than its starting node, using the calculated shortest path group information or the topology information for a path not included in the calculated shortest path group.

Abstract: A calculating apparatus calculates a shortest path connecting two nodes of a network. A shortest-path group, which is a set of shortest paths having node Y as their starting points, can be calculated at once by having calculated a shortest path having node Y as its starting point for each of other nodes. When the shortest-path group having node Y as the starting point is calculated and further if a group of shortest paths having node X as their starting points is stored beforehand in a storing unit, then path portions, which belong to the group of shortest paths having node X as the starting points and further which are paths extending from node Y to the nodes located downstream from node Y, are utilized as part of a result of calculation of the shortest path group having node Y as the starting point.

Abstract: Calculation of a shortest path connecting two nodes of a network involves steps of: comparing a distance of a first communication path between, from among the plurality of nodes, a starting node as a starting point of a communication path and an adjacent node located adjacent to the starting node, to a distance of a second communication path which has already been calculated other than the first communication path and has already been stored; either taking the first communication path as a candidate of the shortest path if the distance of the first communication path is shorter than the second communication path, or taking the second communication path as a candidate of the shortest path if the distance of the first communication path is not shorter than the second communication path; and taking the adjacent node as a next starting node in the comparison step.

Abstract: An optical network has: sections for establishing optical paths; a plurality of optical edge routers for connecting external IP networks to the optical network (1001); and a plurality of optical cross connects, for connecting the optical edge routers by the optical paths, having switching sections with respect to an optical pulse unit. In the optical network, each of the optical edge routers has both of: (1) an optical network control instance (INSp) for maintaining topology information in the optical network and switching/signaling the optical paths; and (2) an IP network instance (INSi) for maintaining a routing table in each of the external IP networks and activating routing protocols between the external IP networks and the IP network instance. By doing this, it is possible to realize a multi-layer cooperative function and provide highly safe optical networks, etc.

Abstract: A calculating apparatus calculates a shortest path connecting two nodes of a network. A shortest-path group, which is a set of shortest paths having node Y as their starting points, can be calculated at once by having calculated a shortest path having node Y as its starting point for each of other nodes. When the shortest-path group having node Y as the starting point is calculated and further if a group of shortest paths having node X as their starting points is stored beforehand in a storing unit, then path portions, which belong to the group of shortest paths having node X as the starting points and further which are paths extending from node Y to the nodes located downstream from node Y, are utilized as part of a result of calculation of the shortest path group having node Y as the starting point.

Abstract: A path calculation order deciding method that is implemented by a calculating apparatus (1) which calculates, by use of calculated shortest path between a node pair about a network comprising a plurality of nodes, a shortest path between other node pair comprises: wherein the calculating apparatus comprises a memory medium storing shortest path group information which represents calculated shortest paths each of which is shortest path between the node pair, whose starting nodes are identical and terminating nodes are different from one another, by use of the plurality of nodes and paths between the node pairs and also storing topology information representing topology of the plurality of nodes, and a calculation unit, a calculation step that the calculation unit selects each particular nodes of the plurality of nodes, which is different from the starting node, in decreasing order of the numbers of the downstream nodes from the particular node in calculated shortest path between the node pair represented by th

Abstract: A data transfer apparatus and a data transfer system are provided that can reduce the cost of installing communication equipment compatible with each of several dissimilar communication protocols in one exchange office and can reduce the cost of constructing the network.

Abstract: A data transfer apparatus and a data transfer system are provided that can reduce the cost of installing communication equipment compatible with each of several dissimilar communication protocols in one exchange office and can reduce the cost of constructing the network.

Abstract: An optical network has: sections for establishing optical paths; a plurality of optical edge routers for connecting external IP networks to the optical network (1001); and a plurality of optical cross connects, for connecting the optical edge routers by the optical paths, having switching sections with respect to an optical pulse unit. In the optical network, each of the optical edge routers has both of: (1) an optical network control instance (INSp) for maintaining topology information in the optical network and switching/signaling the optical paths; and (2) an IP network instance (INSi) for maintaining a routing table in each of the external IP networks and activating routing protocols between the external IP networks and the IP network instance. By doing this, it is possible to realize a multi-layer cooperative function and provide highly safe optical networks, etc.

Abstract: A routing table generating unit that generates a routing table describing a next hop to which a packet is to be sent according to a destination address of the packet that is input via an input channel, including a ternary content addressable memory (TCAM); an external memory; a unit that classifies items in information that is received; and a unit that stores an item that uniquely identifies the information among the classified items in the TCAM and stores the rest of the items to the external memory.