Openflow switch and failure recovery method in openflow network

Patent metadata

Field	Value
Publication number	US-9628324-B2
Application number	US-201514665564-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Apr 14, 2014
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

An OpenFlow switch used in an OpenFlow network including a plurality of OpenFlow switches and an OpenFlow controller configured to control the plurality of OpenFlow switches includes: a failure detector configured to detect a failure of a link connected to the OpenFlow controller; and a channel management unit configured to establish an OpenFlow channel to transmit control information to the OpenFlow controller through another OpenFlow switch among the plurality of OpenFlow switches when a failure is detected by the failure detector.

First claim

What is claimed is:

1. A failure recovery method used in an Open Flow network including a plurality of OpenFlow switches and an OpenFlow controller configured to control the plurality of OpenFlow switches, wherein
the OpenFlow controller has a memory in which a proxy OpenFlow switch for a first OpenFlow switch among the plurality of OpenFlow switches is registered, the proxy OpenFlow switch being one of the plurality of OpenFlow switches other than the first OpenFlow switch and wherein the failure recovery method comprises:
detecting, both in the first OpenFlow switch and the OpenFlow controller, a failure on a link between the first OpenFlow switch and the OpenFlow controller when a failure occurs on the link between the first OpenFlow switch and the OpenFlow controller;
transmitting a first request to establish an OpenFlow channel from the first OpenFlow switch to a second OpenFlow switch among the plurality of OpenFlow switches when the first OpenFlow switch detects the failure on the link between the first OpenFlow switch and the OpenFlow controller;
establishing a first OpenFlow channel between the first OpenFlow switch and the second OpenFlow switch in response to the first request;
transmitting a second request to establish an OpenFlow channel from the second OpenFlow switch to the OpenFlow controller when the second OpenFlow switch receives the first request from the first OpenFlow switch;
allowing the second request when the OpenFlow controller detects the failure on the link between the first OpenFlow switch and the OpenFlow controller and the second OpenFlow switch that has transmitted the second request is registered as the proxy OpenFlow switch for the first OpenFlow switch in the memory; and
establishing a second OpenFlow channel between the second OpenFlow switch and the OpenFlow controller when the second request is allowed.

2. The failure recovery method according to claim 1 , further comprising:
configuring a forwarding circuit in the second OpenFlow switch so as to forward control information transmitted from the first OpenFlow switch through the first OpenFlow channel to the OpenFlow controller through the second OpenFlow channel and forward control information transmitted from the OpenFlow controller through the second OpenFlow channel to the first OpenFlow switch through the first OpenFlow channel.

3. The failure recovery method according to claim 1 , wherein
the second OpenFlow channel is established on a connection established between the second OpenFlow switch and the OpenFlow controller in response to the second request.

4. The failure recovery method according to claim 1 , wherein
the second OpenFlow channel is established on a connection that has been established in advance between the second OpenFlow switch and the OpenFlow controller.

5. The failure recovery method according to claim 1 , wherein
the second OpenFlow switch is designated in advance for the first OpenFlow switch.

6. The failure recovery method according to claim 5 , wherein
a path between the first OpenFlow switch and the second OpenFlow switch is designated in advance for the first OpenFlow switch.

7. The failure recovery method according to claim 1 , wherein
the first OpenFlow switch adds an identifier to identify communication between the first OpenFlow switch and the OpenFlow controller to the control information and transmits the control information through the first OpenFlow channel, and
the OpenFlow controller adds the identifier to the control information and transmits the control information through the second OpenFlow channel.

8. The failure recovery method according to claim 1 , wherein
the OpenFlow controller collects statistical information that represents traffic amount of each OpenFlow switch,
the OpenFlow controller specifies an OpenFlow switch with the least traffic amount based on the statistical information,
the OpenFlow controller transmits an instruction to notifies the first OpenFlow switch of the specified OpenFlow switch, and
the first OpenFlow switch transmits to the OpenFlow switch specified by the OpenFlow controller a request to establish an OpenFlow channel between the first OpenFlow switch and the OpenFlow controller.

9. The failure recovery method according to claim 1 , further comprising:
collecting statistical information that represents a load of each OpenFlow switch, and
determining the second OpenFlow switch in accordance with the statistical information.

Assignees

• Fujitsu Ltd

Inventors

• Yamashita Shinji
• Yamada Akiko
• Soumiya Toshio
• Shimizu Sho
• Nakatsugawa Keiichi

Classifications

• H04L41/0654 Primary

  using network fault recovery (ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437) · CPC title

• H04L41/40

  using virtualisation of network functions or resources, e.g. SDN or NFV entities · CPC title