Packet transfer path control apparatus and control program therefor

A packet transfer path control apparatus which controls a transfer of a unicast packet and a multicast packet, comprising:

• an output port determination unit determining an output port through which a packet input from any of one or more input ports is to be output;
• a pointer storage unit storing for each output port a pointer to a location where there is stored data of a last input one of the unicast packets to be output through the output port or packet management data for the last input unicast packet;
• a packet data storage unit storing data of each input packet;
• a packet output unit provided for each output port, reading data of a packet determined by said output port determination unit to be output through the output port in an output order for guarantee of an input/output order of a unicast packet and a multicast packet based on stored contents of said pointer storage unit from said packet data storage unit, and outputting the read data through the output port.

A program used to direct a computer to control a transfer of a unicast packet and a multicast packet, comprising:

• a procedure of determining one of output ports through which one a packet input through an input port is to be output;
• a procedure of, if the input packet is a unicast packet to be output through the one output port, writing, for the one output port, order identification information assigned for the unicast packet in a table storing for each output port the management information about each unicast packet to be output thorough the output port, the order identification information being assigned to all packets to be output through all of the output ports or all packets to be output through each port in to input order;
• and
• a procedure of, if the input packet is a multicast packet to be output through the one output port, writing order identification information assigned for the multicast packet in a table provided for the one output port and storing the management information about each multicast packet to be output through the one output port, the order identification information being assigned to all packets to be output through all of the output ports or all packets to be output through each port in to input order.

A program used to direct a computer to control a transfer of a unicast packet and a multicast packet, comprising:

• a procedure of determining one of output ports through which one a packet input through an input port is to be output;
• a procedure of, when the input packet is a unicast packet, storing for the one output port a storage address in a table storing management information about the input packet or a storage address in a table storing the data of the input packet;
• and
• a procedure of, when the packet is a multicast packet, writing in a table storing management information about a multicast packet for each output port through which the packet is to be output a storage address in a table storing management information about a unicast packet stored corresponding to the output port or a storage address in a table storing the data of the packet.

A packet transfer path control apparatus which controls a transfer of a unicast packet and a multicast packet, comprising:

• output port determination means for determining an output port through which a packet input from any of one or more input ports is to be output, and assigning output order identification information for designation of an output order of the packet;
• packet data storage means for storing data of the input packet;
• and
• packet output means provided for each of a plurality of output ports for reading data of a packet determined by said output port determination unit to be output through the output port in an output order indicated by the output order identification information from said packet data storage means, and outputting the read data through the output port.

A packet transfer path control apparatus which controls a transfer of a unicast packet and a multicast packet, comprising:

• output port determination means for determining an output port through which a packet input from any of one or more input ports is to be output;
• pointer storage means for storing for each output port a pointer to a last input one of unicast packets to be output through the output port, or packet management information about the last input unicast packet;
• packet data storage means for storing data of each input packet;
• a plurality of packet output means provided for a plurality of output ports for reading data of a packet determined by said output port determination means to be output through the output port in an output order for guarantee of an input/output order of a unicast packet and a multicast packet based on stored contents of said pointer storage means from said packet data storage means, and outputting the read data through the output port.