Switch system, sub-switch and method of controlling switch system

A sub-switch connectable to a first I/O device, a second I/O device and a slave sub-switch, the sub-switch comprising:

• a first bus;
• a first bridge connected to the first bus for receiving a packet from the first I/O device and transmitting the received packet to the first bus, the first bridge being capable of transmitting a request to the first bus so as to inquire whether there is any bridge addressed by the packet via the first bus, the first bridge being capable of receiving an acknowledge from any bridge addressed by the packet via the first bus before transmitting the packet to the first bus;
• a second bridge connected to the first bus for receiving the packet from the first bridge via the first bus, comparing address information of the second bridge with address information included in the packet, and transmitting the packet to the second I/O device when the address information of the second bridge matches with the address information included in the packet;
• a third bridge connected to the first bus for receiving the packet from the first bridge via the first bus and transmitting the packet to the slave sub-switch;
• and
• a table including address information of any bridge of the slave sub-switch;
• wherein the first bridge determines whether the address information included in the packet matches with the address information of the any bridge of the slave sub-switch or not in reference to the table, and transmits the packet to the any bridge of the slave sub-switch when the address information included in the packet matches with the address information of the any bridge of the slave sub-switch.

A method of controlling a switch system connectable to a first I/O device, a second I/O device and a third I/O device, the switch system including a master sub-switch and a slave sub-switch, the method comprising:

• receiving a packet from the first I/O device and transmitting the received packet to a first bus by a first bridge included in the master sub-switch connected to the first bus, the first bridge being capable of transmitting a request to the first bus so as to inquire whether there is any bridge addressed by the packet via the first bus, the first bridge being capable of receiving an acknowledge from any bridge address by the packet to the first bus before transmitting the packet to the first bus;
• receiving the packet from the first bridge via the first bus, comparing address information of the second bridge with address information included in the packet, and transmitting the packet to the second I/O device when the address information of the second bridge matches with the address information included in the packet by a second bridge included in the master sub-switch, connected to the first bus;
• receiving the packet from the first bridge to the first bus and transmitting the packet via the slave sub-witch by a third bridge included in the master sub-switch, connected to the first bus;
• receiving the packet from the third bridge and transmitting the packet to a second bus by a fourth bridge included in the slave sub-switch;
• and
• receiving the packet from the fourth bridge to the second bus, comparing address information of the fifth bridge with address information included in the packet, and transmitting the packet to the third I/O device when the address information of the fifth bridge matches with the address information included in the packet by a fifth bridge included in the slave sub-switch,
• wherein the master sub-switch has a table including address information of the fifth bridge, and the first bridge determines whether the address information included in the packet matches with the address information of the fifth bridge or not in reference to the table, and transmits the packet to the fifth bridge when the address information included in the packet matches with the address information of the fifth bridge.