Patent ID: 7330424

Claim:
A node device for connecting a plurality of networks at least one of said plurality of networks having higher speed transmission lines than other transmission lines in the plurality of networks, said node device comprising: a plurality of input units for respectively inputting data from first transmission lines installed in each of said plurality of networks; a plurality of output units for respectively outputting data to second transmission lines installed in each of said plurality of networks; a first switching unit for switching the data input from said input units to said output units; a control unit transmitting switching information only via the higher speed transmission lines and at least one higher speed input unit when trouble occurs in the higher speed transmission lines shared by said plurality of networks; and a memory unit for storing ring construction information that indicates that said first transmission lines and said second transmission lines connect to which of said plurality of networks; a transmission unit for producing topology information, squelch information and switching information concerning each of said plurality of networks on the basis of said ring configuration information for each of the said corresponding networks, and transmitting said topology information, said squelch information and said switching information via said output units; and a second switching unit for performing processing including switching operations and bridging operations on the basis of said switching information, wherein the input unit that inputs data from the transmission line shared by said plurality of networks to be output to the higher speed transmission lines has a higher transmission speed than other input units.