Packet repeater

A repeater having a plurality of ports for transmitting and receiving packets to form a ring type network, comprising:

• a transmitting port database operble to indicate correspondence among an address included in a received packet, a port identifier to transmit a packet having the address as the destination, and a number of hops indicating a number of repeaters used to transfer the packet having the address as the destination up to an external side of the ring type network;
• a packet processing block operable to determine a transmitting destination port of the received packet on the basis of the transmitting port database and transmitting the received packet from the determined port;
• a control packet processing block operable to detect reception of a fault notifying packet transmitted from the repeater having detected a fault, extracting the number of hops in a fault section indicating the number of repeaters used to transfer the packet up to its own repeater from the fault section included in the fault notifying packet, and notifying the number of hops in the fault section to a control block;
• and
• a control block operable to update an identifier of the port having received a fault notifying packet, the number of hops corresponding to the port identifier of the transmitting port database, and the number of hops corresponding to the port identifier of the transmitting port database on the basis of the extracted number of hops in the fault section.

A packet transfer method in a repeater having a plurality of ports for transmitting and receiving packets to form a ring type network, comprising the steps of:

• converting the packets, when the packets received from the ports other than that connected to the adjacent repeaters are to be transmitted from the ports connected to the adjacent repeaters, into the packets to which a ring tag including the hop number field setting the initial value and then transmitting these packets to the ports connected to the adjacent repeaters;
• recording, to the transmitting port database, the correspondence among the transmitting source address of the packets, identifiers of the ports having received the packets, and the predetermined value as the number of hops indicating the number of repeaters used to transfer the packets to the outside of the ring type network;
• recording, upon reception of the packets to which the ring tags are added, the correspondence among the transmitting source address of the packets, port identifiers of the ports having received the packets, and the value of the hop number field of the packets to the transmitting port database and then transmitting the packets having updated the hop number field with the value obtained by adding one (1) to the value of the hop number field of the packets from t he output port determined in accordance with the transmitting port database;
• extracting, upon reception of the fault notifying packet transmitted from the repeater having detected the fault, the number of hops in the fault section indicating the number of repeaters used to transfer the packet to the repeater having received the fault notifying packet from the fault section;
• and
• updating the port identifier of the transmitting port database and the corresponding number of hops on the basis of the identifier of the port having received the fault notifying packet, the number of hops corresponding to the port identifier of the transmitting port database and the extracted number of hops in the fault section.