# US 2019/0356598 A1 · Information processing system

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- Number: US 2019/0356598 A1
- Document ID: US20190356598A1
- Status: Published application
- Kind: A1
- Application number: 16/413,868
- Filed: 2019-05-16
- Published: 2019-11-21
- Earliest claimed: 2018-05-18
- Assignees: Allied Telesis Holdings K.K.
- Applicants: Allied Telesis Holdings K.K.
- Inventors: Yohei Kikuchi
- Web page: https://patentgrep.com/patent/US20190356598A1

## CPC

- H04L 45/02: Topology update or discovery
- H04L 47/2483: involving identification of individual flows
- H04L 47/32: by discarding or delaying data units, e.g. packets or frames
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

There is provided an information processing system using a controller and a switch, wherein the switch transmits a predetermined message to all controllers to be connected when it is determined that there is no flow entry for a packet from a terminal to be connected in a flow table, and the controller sets the flow entry for discarding the packet in the flow table of the switch with low priority when it is determined that the predetermined message received from the switch does not satisfy a predetermined condition.

## Claims

### Claim 1

An information processing system using a controller and a switch, wherein:
the switch transmits a predetermined message to all controllers to be connected when it is determined that there is no flow entry for a packet from a terminal to be connected in a flow table; and
the controller sets the flow entry for discarding the packet in the flow table of the switch with low priority when it is determined that the predetermined message received from the switch does not satisfy a predetermined condition.

### Claim 2 (depends on 1)

The information processing system according to claim 1, wherein:
the predetermined condition is one or more of the predetermined message from a registered switch, the predetermined message from a registered port, or the predetermined message for a packet from a terminal that is authorized to connect.

### Claim 3 (depends on 2)

The information processing system according to claim 2, wherein:
when the controller determines that the predetermined message received from the switch satisfies a predetermined condition, the flow entry for transmitting the packet to a network controlled by an SDN controller is set in the flow table of the switch with normal priority.

### Claim 4

An SDN controller used in a network constructed by an SDN, wherein:
the SDN controller receives, from a switch, a message indicating that there is no flow entry for a packet from a terminal connected to the switch in a flow table; and
the SDN controller sets the flow entry for discarding the packet in the flow table of the switch with low priority when it is determined that the message received from the switch does not satisfy a predetermined condition.

### Claim 5

A switch used in a network constructed by an SDN, wherein
the switch transmits a predetermined message to all controllers to be connected when it is determined that there is no flow entry for a packet from a terminal to be connected in a flow table;
the switch receives, from the controller, a flow entry with low priority for discarding the packet when the controller determines that the message does not satisfy a predetermined condition; and
the switch sets the received flow entry in the flow table.