Hitachi Metals, Ltd.

Tomoyoshi Tatsumi

Shingo Sugawara

Koichiro Seto

Wataru Kumagai

Hiroshi Ishizaki

A communication system and a network relay device capable of improving failure tolerance are provided. For example, three port switches, fabric switches, and user switches are provided, and two of the port switches configure a multi-chassis link aggregation device. Each of the fabric switches detects the number of the port switches (for example, two switches) connected without failure while logically regarding the port switches configuring the multi-chassis link aggregation device as one switch, and transmits the number of the switches (two switches) from three ports. Each of the port switches sets a link aggregation group for two of the ports which have received the largest number of the switches (two switches).

Communication system and network relay device

Each of the n port switches set LAG to m links which respectively connect the port switch and m fabric switches. For example, the port switch performs a hashing operation for a frame received at a predetermined port and containing a layer 4 port number of an OSI reference model by using the port number, determines one link based on a result of the hashing operation from among the m links to which the LAG is set, and relays the frame to the one link.

Network relay system and switching device

A communication system includes a plurality of port switches that include first and second port switches, a plurality of fabric switches that construct communication paths among the plurality of port switches, and a user switch. Each of the plurality of port switches is connected to each of the plurality of fabric switches via different communication lines. The first and second port switches are connected by a common communication line between redundancy ports of the first and second port switches to thereby form a same domain group. The user switch is connected to each of the first and second port switches via different communication lines, and also sets link aggregation for ports of the user switch that are connection sources of the communication lines that connect the user switch and each of the first and second port switches.

When a fabric switch detects a fault in its own link, the fabric switch transmits a first fault notification frame containing a fault link identifier representing the detected fault to a plurality of port switches. When the fabric switch receives a second fault notification frame from a plurality of port switches, it floods the second fault notification frame. When a port switch detects a fault in its own link, it transmits a second fault notification frame containing a fault link identifier to the plurality of fabric switches. Also, when the port switch receives the fault notification frame at all of its own links, it sets the LAG based on the fault link identifier.

Relay system and switching device

A port switch of type A has a distribution mode for maintaining a backward compatibility with a port switch of type B. A distribution identifier calculating unit performs a logical operation with the same operational expression to the same bit region as the type B in a header contained in a frame, thereby calculating a k-bit (k&#x3e;j) distribution identifier partly containing the same j-bit bit region as the type B. A distribution table indicates a correspondence relation between three sub-links and the k-bit distribution identifier, and has contents in which the j-bit distribution identifier in the distribution table of the type B is replaced with the k-bit distribution identifier partly containing the same j-bit value as that of the j-bit distribution identifier.

There is provided port switches SWPto SWP, fabric switches SWFand SWF, and user switches SWUand SWU, the port switches SWP, SWPfunctioning logically as one switch by being connected with a shared communication line between redundancy ports Pr. The port switch SWPmay receive frames from the user switch SWU, and when the frames are to be originally transferred from a port Pto the fabric switch SWF, the frames are transferred though the redundancy port Pr to the port switch SWPif there is a fault on the port Pside. The port switch SWPtransfers the frames received from the port switch SWPthrough the redundancy port Pr to the fabric switch SWFthat is the original transfer destination.

A network system has lower switches and upper switches connected to the lower switches. Each of the upper switches includes a connection information notifying means for notifying connected lower switch list informations each of which includes an identification information on each of the lower switches connected to each of the upper switches, to the lower switches connected to each of the upper switches. Each of the lower switches includes a comparison determination means for comparing the connected lower switch list informations notified by the connection information notifying means, in order to determine a connection state between the upper switches and the lower switches.

Network system

A port switch includes ports that are to serve as communication sources of communication lines extending to a plurality of fabric switches, and sets a link aggregation for the ports. The port switch further includes a fabric switch table indicating a correspondence relationship between each of the addresses of the fabric switches and the corresponding one of the ports. When the port switch receives a frame from a terminal, the port switch detects a destination address in the frame, determines, if the destination address is one of the addresses in the fabric switch table, a port corresponding to the one of the addresses, on the basis of the fabric switch table to transfer the frame from the port.

Communication system and network relay apparatus

A network system includes lower switches and upper switches connected to the lower switches. Each of the upper switches transmits a first notification frame containing a connected lower switch number information indicative of the number of the lower switches connected to each of the upper switches, to the lower switches connected to each of the upper switches. Each of the lower switches configures a link aggregation group for ports which received the first notification frames each of which contains a maximum value of the connected lower switch number information among the connected lower switch number informations contained in the received first notification frames.

A network system includes a plurality of lower switching hubs, and upper switching hubs connected to each of the lower switching hubs, to relay a normal frame to be transmitted and received between the lower switching hubs. Each of the lower switching hubs includes a lower switch configuring portion for configuring a first link aggregation group for all ports connected to the upper switching hub, and transmitting a first control frame containing its own identifier from all the ports connected to the one or more upper switching hubs. Each of the upper switching hubs includes an upper switch configuring portion for configuring a second link aggregation group for ports connected to a same lower switching hub, based on the first control frames received from the lower switching hubs, and transmitting a second control frame containing its own identifier from the ports configured as the second link aggregation group.

FSs (to) are each connected to IFSs (to). Each of the FSs (to) transmits a setting frame () that includes an FS number to the connected IFSs (to). Each of the IFSs (to) registers, in an LAG setting table, the FS numbers included in the received setting frames () and ports that have received the same in association with each other. Then, each of the IFSs (to) sorts ports (to) in an order of the associated FS numbers, and sets each of LAGs (to) in a common order.

Network relay system and method of automatically setting a network relay system

A network relay system () includes a plurality of IFSs () and a plurality of FSs (). The IFSs (to) are each connected to the FSs (to) through physical lines. In the IFSs (), an LAG is set for ports connected to the FSs (). The IFSs () and the FSs () transmit/receive a detection frame to/from each other, and when the detection frame fails to be received, it is determined that a failure has occurred within the network relay system (). When one of the FSs () determines that a failure has occurred, the one of the FSs () transmits a failure notification frame to the plurality of IFSs (), and each of the plurality of IFSs () excludes the port that has received the failure notification frame from the LAG.

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Tsuchiura, Japan

Tomoyoshi Tatsumi