Router apparatus using ATM switch

Abstract

A router apparatus 5 is provided with an ATM switch, an IP controller for performing routing control as a controller for layer 3 , plural kinds of interfaces which are individually provided to plural transmission paths in which various communications are performed, and a cell multiplexing/demultiplexing unit, and manages the cell communications between respective parts on the basis of identification information. The input packet is subjected to IP processing in an interface to be converted to a cell in a common format, and the cell is serially multiplexed with a cell from another interface on a cell basis, and transmitted to the ATM switch at the cell multiplexing/demultiplexing unit. Each interface and each cell multiplexing/demultiplexing unit sets and switches the identification information for the header portion of the packet and the cell to be communicated by using a table in which the corresponding relationship of the identification information is registered.

1 . A packet switching device which switches packets comprising: 
 managing means which manages route information of said packets;    a control unit which controls said packet switching device as a whole;    a plurality of input line interfaces,    wherein each line interface comprises:    receiving means which receives variable-length packets from an input line,    storage means which stores therein said route information from said control unit,    determining means which determines routes of said variable-length packets received based on contents of said variable-length packets and said route information stored in said storing means, and    means for converting said variable-length packets into a plurality of fixed-length packets respectively, and outputting each of said fixed-length packets by adding thereto said route information determined by said determining means;    a multiplexing unit which receives said plurality of the fixed-length packets outputted from said plurality of line interfaces, and multiplexes said fixed-length packets to output a plurality of fixed-amount packets each having different route information;    a switch which receives said plurality of fixed-length packets each having different route information outputted from said multiplexing unit and outputting each of the fixed-length packets in accordance with said route information attached thereto; and    an output line interface which receives said plurality of the fixed-length packets outputted from said switch and assemble the original variable length packets therefrom to output them to an output line.    
   
   
       2 . A packet switching device according to  claim 1 , wherein said variable-length packets use Internet Protocol (IP).