Path management control method, path management control program, path management controller and path management control system

A path management controlling method using a path management controller comprising:

• an input/output unit for controlling input/output of various data;
• a storage unit for storing
• (1) route information including identification information regarding each link used for a path that connects nodes,
• (2) in association with the identification information of each link, resource information including identification information of advance reserved paths and working paths that use that link and a residual bandwidth of that link in chronological order,
• (3) in association with the identification information of each working path, path information including identification of links and a bandwidth used in the working path, and
• (4) in association with the identification information of each advance reserved path, path reservation information including a bandwidth used in that advance reserved path and a period of use of that advance reserved path;
• a route calculating section for calculating a route for a new future reserved path with reference to the route information, the resource information, the path information and the path reservation information;
• and
• a path setting section for setting a path between each pair of nodes in a network, based on the path reservation information or a path setting request for setting a path, which is input via the input/output unit, wherein
• the path management controlling method that allows the path management controller to execute steps of:
• via the input/output unit, receiving a path setting request for setting a new future reserved path, which includes a bandwidth and a period of use requested for the new future reserved path;
• with reference to the route information and the resource information, calculating a route for the new future reserved path;
• with reference to the residual bandwidth of each link at each time included in the chronologically ordered resource information, determining whether or not there is any link that cannot secure a bandwidth of the new future reserved path during the period of use as requested in the path setting request, among links of the route for the new future reserved path;
• when determining that there is such link that cannot secure the bandwidth of the new future reserved path during the period of use as requested in the path setting request, among the links of the route for the new future reserved path, with reference to the route information and the resource information, calculating an alternative route for an already-reserved path that uses the such link that cannot secure the bandwidth of the new future reserved path as requested in the path setting request, among paths registered in the path information and the path reservation information, wherein the alternative route does not use the such link so that the new future reserved path can be reserved;
• and
• updating the resource information and the path reservation information with the calculated alternative route and the route for the new future reserved path,
• wherein,
• the resource information further includes information reqardinq an oriqinal bandwidth of every link, and
• if there are plural links that cannot secure the bandwidth during the period of use as requested in the path setting request, among the links in the calculated route for setting the advance reserved path,
• the method allows the path management controller to execute further steps of:
• when calculating the alternative route for the path, receiving a selection input to select preferentially executing this alternative route calculation in the plural links in the order from a greater original bandwidth, or preferentially executing this alternative route calculation for the plural links in the order from a smaller original bandwidth;
• and
• when calculating the alternative route for the path, based on this received selection input, determining from which link among the plural links the alternative route for the path in the link of interest is preferentially calculated.