NETWORK SYSTEM

• US 20140185619A1
• Filed: 08/24/2011
• Published: 07/03/2014
• Est. Priority Date: 08/24/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Shigeeda, Tetsuya
• Granted Patent: US 9,565,133 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 12/28 characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] wireless communication networks H04W ; arrangements for dividing the transmission path H04W40/00
• CPC Class Codes: H04L 12/462 LAN interconnection over a bridge based backbone
• CPC Class Codes: H04L 12/4625 Single bridge functionality, e.g. connection of two networks over a single bridge
• CPC Class Codes: H04L 2012/40293 the transportation system being a train
• CPC Class Codes: H04L 45/74 Address processing for routing
• CPC Class Codes: H04L 49/15 Interconnection of switching modules
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation

Abstract

To provide a network system including a network constructed by combining a plurality of switching devices. The network includes a first partial network including switching devices and a second partial network that is formed outside the first partial network and includes switching devices. The switching device in the first partial network connected to the second partial network blocks passage of a broadcast signal that is transmitted from a terminal device and that has a specific logical port number as transmission information at a physical port.

Claims

1. A network system including a network constructed by combining a plurality of switching devices, wherein

the network includes a first subnetwork and a second subnetwork that is formed outside the first subnetwork, and

at least one of a switching device in the first subnetwork connected to the second subnetwork and a switching device in the second subnetwork connected to the first subnetwork blocks passage of a broadcast signal that includes a specific logical port number as transmission information.

2. The network system according to claim 1, comprising a terminal device that is connected to the network and can transmit the broadcast signal, wherein

the first subnetwork is constituted by including the terminal device, and

when having received a broadcast signal including the specific logical port number as transmission information transmitted from the terminal device in the first subnetwork, the switching device in the first subnetwork connected to the second subnetwork blocks passage of the broadcast signal into the second subnetwork at a physical port to which the second subnetwork is connected.

3. The network system according to claim 2, wherein

the second subnetwork is constituted by including the terminal device, and

when having received a broadcast signal including the specific logical port number as transmission information transmitted from the terminal device in the second network, the switching device in the second subnetwork connected to the first subnetwork blocks passage of the broadcast signal into the first subnetwork at a physical port to which the first subnetwork is connected.

4. The network system according to claim 3, wherein

the network is constructed in a train formed with a plurality of vehicles,

a subnetwork including the switching device, the terminal device, and an apparatus connected to corresponding switching device is formed in each of the vehicles,

the first subnetwork is a subnetwork provided in a first vehicle, which is an arbitrary vehicle of the plurality of vehicles, and

the second subnetwork is a subnetwork provided in a second vehicle coupled to the vehicle in which the first subnetwork is provided.

5. The network system according to claim 4, wherein

the second vehicle is coupled to a third vehicle,

a third subnetwork, which is a subnetwork including the switching device, the terminal device, and the apparatus connected to corresponding switching device, is formed in the third vehicle, and

when having received a broadcast signal including the specific logical port number as transmission information transmitted from the terminal device in the second network, the switching device in the second subnetwork connected to the third subnetwork blocks passage of the broadcast signal into the third subnetwork at a physical port to which the third subnetwork is connected.

6. The network system according to claim 5, wherein

the broadcast signal includes a broadcast address as a transmission destination address, a transmission source address, a logical port number, and a data portion, and

the data portion includes information of a vehicle in which the terminal device is incorporated.

7. The network system according to claim 6, wherein the terminal device is a train-information management device.

8. The network system according to claim 7, wherein two of the terminal devices are incorporated in each of the vehicles to form a dual system.

9. The network system according to claim 2, wherein

the second subnetwork is constituted including the terminal device, and

when having received a broadcast signal including the specific logical port number as transmission information transmitted from the terminal device in the second network, the switching device in the first subnetwork connected to the second subnetwork blocks passage of the broadcast signal into the first subnetwork at a physical port to which the second subnetwork is connected.

10. The network system according to claim 1, comprising a terminal device that is connected to the network and can transmit the broadcast signal, wherein

the first and second subnetworks are respectively constituted by including the terminal device,

when having received a broadcast signal including the specific logical port number as transmission information transmitted from the terminal device in the second network, the switching device in the first subnetwork connected to the second subnetwork blocks passage of the broadcast signal into the first subnetwork at a physical port to which the second subnetwork is connected, and

when having received a broadcast signal including the specific logical port number as transmission information transmitted from the terminal device in the first network, the switching device in the second subnetwork connected to the first subnetwork blocks passage of the broadcast signal into the second subnetwork at a physical port to which the first subnetwork is connected.