Node device used in network system for packet communication, network system using such node devices, and communication method used therein

A network system comprising:

• a transmission line comprising a plurality of channels;
• and
• a plurality of node devices for performing packet communication using said transmission line, said plurality of node devices connecting said transmission line to sub-transmission lines,
• each of said plurality of node devices comprising:
• packet processing means for processing a packet;
• first means corresponding to each of said plurality of channels, for outputting a packet input on a predetermined one of said plurality of channels to one of said sub-transmission line side and said transmission line side;
• second means corresponding to each of said plurality of channels, for outputting a packet transmitted through said sub-transmission line to one of said transmission line side and said packet processing means side;
• third means for outputting a packet supplied thereto from said packet processing means to said sub-transmission line side;
• memory means corresponding to each of said first means and said second means, for temporarily storing a packet output from each of said first means and said second means;
• and
• transmission means for transmitting outputs from said memory means in said channel different from each other.

A communication method in a network system having a plurality of node devices, each of the plurality of node devices performing packet communication using a transmission line having a plurality of channels, said plurality of node devices connecting terminals to the transmission line, said method comprising the steps of:

• storing in a storing unit connection information indicative of a channel to which each of the terminals is connected in the network system;
• and
• selecting the channel to which a packet to be transmitted is output,
• wherein when the packet is transmitted from the first terminal to the second terminal, information indicative of the channel to which the second terminal is connected is added to the packet, and the packet is transmitted on the channel to which the second terminal is connected, in the node device before the node device to which the second terminal is connected.

A control method of a node device for performing packet communication using a transmission line having a plurality of channels, said node device connectable to a network system having a plurality of node devices connecting the transmission line to sub-transmission lines, the network system including packet processing means for processing a packet, said control method comprising:

• a first step for outputting a packet input on a predetermined one of the plurality of channels to one of a side of the sub-transmission line and a side of the transmission line, in first means corresponding to each of the plurality of channels;
• a second step for outputting a packet transmitted through the sub-transmission line to one of the transmission line side and the packet processing means side, in second means corresponding to each of the plurality of channels;
• a third step for outputting a packet supplied from the packet processing means to the sub-transmission line side;
• a storing step for temporarily storing the packet output from the first means and the second means to memory means corresponding to each of the first means and the second means;
• and
• a transmission step for transmitting outputs from the memory means in the channels different from each other.