Abstract: In a packet transport network, to determine a path route in which a bottleneck does not occur with a small amount of calculation, provided is a network system, including data transfer devices and a management computer, each of the data transfer devices including IFs, in which the management computer is configured to: store remaining bandwidth information on the each of the IFs; select one of bandwidths; judge, based on the remaining bandwidth information and the selected bandwidth, whether or not the each of the IFs is usable; determine a route candidate though which data is transferred, bypassing the each of the IFs which has been judged to be unusable; judge, based on the remaining bandwidth information, whether or not continuity of the IF through which the route candidate passes is possible; and allocate the route candidate, the continuity of which is possible, to a new path.

Abstract: In a packet transport network, to determine a path route in which a bottleneck does not occur with a small amount of calculation, provided is a network system, including data transfer devices and a management computer, each of the data transfer devices including IFs, in which the management computer is configured to: store remaining bandwidth information on the each of the IFs; select one of bandwidths; judge, based on the remaining bandwidth information and the selected bandwidth, whether or not the each of the IFs is usable; determine a route candidate though which data is transferred, bypassing the each of the IFs which has been judged to be unusable; judge, based on the remaining bandwidth information, whether or not continuity of the IF through which the route candidate passes is possible; and allocate the route candidate, the continuity of which is possible, to a new path.

Abstract: If opening and deleting of arbitrary optical pathways are repeated in a configuration where plural OADM nodes are connected to each other in a ring manner, empty waves in the ring are fragmented, and thus, it is necessary to optimize the optical pathways. When an optical pathway is opened from an OADM node to a different OADM node, transponders capable of connecting two routes to the OADM nodes and of setting different wavelengths for two routes are mounted in a state where there are no empty waves on a part of the route, so that an already-opened optical pathway is detoured to a detour route or a different wavelength in the OADM ring, and continuous empty waves are produced in a section to be opened so as to open a new optical pathway.

Abstract: A high-manganese, non-magnetic steel having excellent weldability and machinability and suitable for use in the structural parts of electrical equipment or nuclear fusion equipment consisting essentially of (% by weight):______________________________________ carbon 0.55-0.80 silicon 0.1-1.2 manganese 10.0-14.5 nickel 0.3-3.0 chromium 0.5-3.6 nitrogen 0.01-0.2 ______________________________________balance iron and inevitable impurities. The steel may further contain at least one element of 0.01 to 1.0% of molybdenum, 0.01 to 0.5% of vanadium, 0.01 to 0.5% of niobium, 0.005 to 0.5% of titanium, 0.01 to 1.0% of zirconium, 0.0007 to 0.005% of calcium, 0.01 to 0.15% of sulfur, 0.03 to 0.2% of selenium, 0.03 to 0.2% of lead, and 0.01 to 0.8% of tin.