Method for acquiring, by SDN switch, exact flow entry, and SDN switch, controller, and system

Patent metadata

Field	Value
Publication number	US-10367718-B2
Application number	US-201715681659-A
Country	US
Kind code	B2
Filing date	Aug 21, 2017
Priority date	Oct 26, 2013
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

Embodiments disclose a method for acquiring, by a switch deployed in a software defined network (SDN), an exact flow entry, where the SDN network includes an SDN controller and multiple SDN switches, the SDN controller being configured to communicate with each SDN switch in an inband communication manner. The method includes establishing, by a first SDN switch, a reliable connection to the SDN controller, and sending a first control message based on a packet corresponding to a protocol for the reliable connection. Path information of the first SDN switch is added to the control message. Each SDN switch that receives the first control message adds path information of each SDN switch to the first control message, so that the SDN controller is provided with an entire path, so as to deliver a flow table to the first SDN switch.

First claim

What is claimed is:

1. A method for controlling a software defined network (SDN), the method comprising:
providing an SDN controller connected to first and second switch devices, the SDN controller being configured to communicate with the first and second switch devices via inband communications;
sending a first control message from the first switch device to the second switch device, the first control message including path information of the first switch device and being carried in a packet corresponding to a protocol used by a reliable connection established between the first switch device and the SDN controller;
generating, by the second switch device, an updated first control message obtained by adding, to the first control message, path information of the second switch device, and sending the updated first control message to the SDN controller;
determining, by the SDN controller, a routing path between the SDN controller and the first switch device in accordance with the path information of the updated first control message; and
sending, from the SDN controller to the first switch device, an exact flow entry according to the routing path.

2. The method according to claim 1 , wherein the reliable connection established between the first switch device and the SDN controller comprises a TCP connection utilizing a TCP/IP packet carrying information about a three-way TCP handshake between the first switch device and the SDN controller.

3. The method according to claim 1 , wherein the SDN network is implemented based on an OpenFlow protocol, the first control message comprising an OFPT_HELLO message as defined in the OpenFlow protocol, a body field of the OFPT_HELLO message carrying the path information.

4. The method according to claim 1 , further comprising receiving a final updated first control message forwarded by the second switch device.

5. The method according to claim 4 , wherein receiving a final updated first control message comprises:
when the SDN network includes a single second switch device, directly receiving the final updated first control message from the second switch device;
and when the SDN network includes a plurality of second switch devices, receiving the final first control message through multiple, interconnected second switch devices, wherein the final updated first control message includes path information of the interconnected second switch devices in the routing path.

6. The method according to claim 1 , wherein the SDN network is implemented based on an OpenFlow protocol, and sending the exact flow entry from the SDN controller to the first switch device according to the routing path comprises:
adding multiple exact flow entries by the first switch device to an OFPT_FLOW_MOD message defined in the OpenFlow protocol; and
sending the OFPT_FLOW_MOD message to the first switch device according to the routing path.

7. The method according to claim 6 , wherein, the first switch device extracts the multiple exact flow entries carried in the OFPT_FLOW_MOD message and adds the multiple exact flow entries to a local exact flow table.

8. The method according to claim 1 , wherein the SDN network is implemented based on an OpenFlow protocol, and sending the exact flow entry to the first switch device according to the routing path comprises:
adding to an OFPT_FLOW_MOD message defined in the OpenFlow protocol, multiple exact flow entries from corresponding multiple switch devices positioned along the routing path and path information corresponding to each switch device on the routing path; and
delivering the OFPT_FLOW_MOD message to the switch devices according to the routing path, each switch device extracting from the OFPT_FLOW_MOD message an exact flow entry required by the next switch device in the routing path.

9. A controller device connectable to first and second switch devices in a software defined network (SDN), the second switch device connected to a first switch device in the SDN, the controller device being configured to communicate with each of the first and second switch devices in an inband communication manner and to:
receive an updated first control message forwarded by the second switch device, wherein the updated first control message is obtained by adding path information of the second switch device to the first control message, the first control message carrying path information of the first switch device and being carried in a packet corresponding to a protocol used by a reliable connection established between the first switch device and the controller device;
acquire a routing path between the controller device and the first switch device according to path information added by each switch device and carried in the updated first control message; and
deliver an exact flow entry to the first switch device through the routing path.

10. The controller device according to claim 9 , wherein the reliable connection established between the first switch device and the controller device comprises a TCP connection utilizing a TCP/IP packet carrying a message of a three-way TCP handshake performed between the first switch device and the controller device.

11. The controller device according to claim 9 , wherein the SDN network is implemented based on an OpenFlow protocol, the first control message comprising an OFPT_HELLO message as defined in the OpenFlow protocol, a body field of the OFPT_HELLO message carrying the path information.

12. The controller device according to claim 9 , wherein the controller device is configured to directly receive a final updated first control message forwarded by the second switch device.

13. The controller device according to claim 8 , wherein the controller device is configured to receive a final updated first control message forwarded by a plurality of interconnected switch devices, the final updated first control message including path information that has been added by each switch device in the routing path between the controller device and the first of the switch devices.

14. The controller device according to claim 9 , wherein the SDN network is implemented based on an OpenFlow protocol, and the controller device is configured to:
add an exact flow entry to an OFPT_FLOW_MOD message as defined in the OpenFlow protocol; and
send the OFPT_FLOW_MOD message to the first switch device through the routing path.

15. The controller device according to claim 9 , wherein the SDN network is implemented based on the OpenFlow protocol, and the controller device is configured to:
add, to an OFPT_FLOW_MOD message as defined in the OpenFlow protocol, multiple exact flow entries corresponding to respective ones of multiple OpenFlow switches located along the routing path and path information corresponding to each OpenFlow switch along the routing path; and
deliver the OFPT_FLOW_MOD message to a respective OpenFlow switch along the routing path.

16. A method for collecting path information in an OpenFlow network comprising an OpenFlow controller (OFC) connected to first and second OpenFlow Switches (OFS), the OFC communicating with each OFS in an inband communication manner, the method comprising:
receiving an OFPT_HELLO message sent by the first OFS and carried in a packet corresponding to a protocol used by a reliable connection established between the first OFS and the OFC, a body field of the OFPT_HELLO message carrying path information;
generating an updated OFPT_HELLO message by adding path information of the second OFS to the OFPT_HELLO message;
forwarding the updated OFPT_HELLO message to the OFC, the OFC determining a routing

Assignees

• Huawei Tech Co Ltd

Inventors

• Zheng Xiuli
• Wen Bailin
• Wang Rong

Classifications

• H04L45/02 Primary

  Topology update or discovery · CPC title

• H04L69/16

  Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] · CPC title

• H04L45/38 Primary

  Flow based routing · CPC title

• H04L45/42

  Centralised routing · CPC title

• H04L45/54

  Organization of routing tables · CPC title