Backhaul failover method and system for a wireless network

• US 20090213730A1
• Filed: 02/21/2008
• Published: 08/27/2009
• Est. Priority Date: 02/21/2008
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Aerohive Networks Incorporated (Extreme Networks, Inc.)
• Inventors: Liu, Changming, Zeng, Jianlin
• Granted Patent: US 7,839,771 B2
• Time in Patent Office: Days
• US Class Current: 370/217
• CPC Class Codes: H04W 24/04 Arrangements for maintaining operational condition
• CPC Class Codes: H04W 88/10 adapted for operation in multiple networks, e.g. multi-mode access points

Abstract

A method and corresponding system for providing for recovering from a failure of a wired link used for communication between the first access point and a wired network. The first access point has at least two radios including a first radio and a second radio each for providing a wireless communications link. The method including selectively configuring the radios in an access mode for enabling a communications path with a corresponding client node to enable each client node to have a communication path via the first access point to the wired network, wherein the first and second radios are enabled to be associated with a first and second client node, respectively. The method and system includes providing communications paths for the client nodes to the wired network in response to detection of loss of the wired link to the first access point by selectively reconfiguring the second radio to a backhaul mode.

Claims

1. A method for recovering from a failure of a wired link used for communication between a first access point and a wired network, said first access point having at least two radios including a first radio and a second radio each for providing a wireless communications link, the method comprising:

selectively configuring said radios in an access mode, each said radio in said access mode for enabling a communications path with a corresponding client node to enable each said client node to have a communication path via said first access point to the wired network, wherein said first radio is enabled to be associated with a first client node, and wherein said second radio is enabled to be associated with a second client node; and

providing a communications path for said first and second client nodes to the wired network in response to detection of loss of the wired link to said first access point by selectively reconfiguring said second radio to a backhaul mode, comprising;

detecting said loss of the wired link to said first access point;

disassociating any client node from said second radio;

detecting a neighboring access point which can provide a link to the wired network for said first access point;

causing said second radio to provide a wireless link to said detected neighboring access point; and

causing said first access point to enable any client nodes associated with said first radio and any client nodes that had been associated with said second radio to have a communication path to the wired network via said first radio wireless link, said second radio wireless link, and said detected neighboring access point'"'"'s wired link.

2. The method of claim 1, wherein said detecting a neighboring access point includes;

causing said second radio to broadcast a request for backhaul connectivity to neighboring access points;

detecting whether any neighboring access point responds to said request; and

selecting a responding neighboring access point based on at least one predetermined criteria.

3. The method of claim 1, further comprising:

detecting recovery of the wired link to said first access point; and

in response thereto, selectively reconfiguring said second radio in said access mode, wherein said second radio is enabled to be associated with said second client node.

4. The method of claim 1, wherein the wired link comprises an Ethernet link and the first access point has an Ethernet port for providing a physical link to the Ethernet link.

5. The method of claim 4, wherein said Ethernet port has a link status indicative of the status of the wired link, and wherein the step of detecting said loss of the wired link to said first access point comprises obtaining said link status and determining therefrom whether the wired link is lost.

6. The method of claim 4, wherein the wired link provides a connection between the Ethernet port and a gateway switch, wherein said gateway switch comprises an address recognizable by an Ethernet protocol;

wherein the step of detecting said loss of the wired link to said first access point comprises periodically requesting said address using the Ethernet link and determining whether the address was received by said first access point in response.

7. The method of claim 6, wherein said gateway switch comprises an Internet Protocol (IP) address and a Media Access Control (MAC) address.

8. The method of claim 6, wherein the periodic requesting comprises transmitting an echo message.

9. The method of claim 8, wherein said echo message is a PING command.

10. The method of claim 8, wherein said echo message is an Address Resolution Protocol (ARP) command.

11. The method of claim 2, wherein said at least one predetermined criteria include that there is a communications path via said responding neighboring AP to the wired network.

12. The method of claim 3, wherein said request and said response to said request each have an associated signal power and wherein said at least one predetermined criteria include that the signal power of said request and said response each exceed a predetermined threshold.

13. The method of claim 3, wherein said first access point has an associated identification code and password, and said at least one predetermined criteria include that said response of said neighboring access point includes the identification code and password of said neighboring access point which matches said first access point'"'"'s identification code and password.

14. The method of claim 2, wherein said selected neighboring access point has at least two radios including a first radio and a second radio each for providing a wireless communications link, the method further comprising:

prior to detecting loss of the wired link, selectively configuring said radios of said detected neighboring access point in an access mode, each said radio of said selected neighboring access point in said access mode for enabling a communications path with a corresponding client node to enable each said client node to have a communication path via said selected neighboring access point to the wired network, wherein said first radio of said selected neighboring access point is enabled to be associated with a third client node, and wherein said second radio of said selected neighboring access point is enabled to be associated with a fourth client node.

15. The method of claim 14, further comprising selectively reconfiguring said second radio of said selected neighboring access point to a backhaul mode, comprising:

disassociating any client node from said second radio if said selected neighboring access point;

causing said second radio of said selected neighboring access point to enable a wireless link to said first access point; and

causing said selected neighboring access point to enable any client nodes that had been associated with said selected neighboring access point'"'"'s second radio to be associated with said selected neighboring access point'"'"'s first radio to provide a communication path to the wired network.

16. The method of claim 2, further comprising

detecting whether said first access point has been reconfigured in an access mode in response to recovery of the wired link to the first access point, and in response thereto, selectively reconfiguring said second radio of said selected neighboring access point in an access mode.

17. The method of claim 6, wherein there are one or more switches in a path between the first access point and the gateway switch.

18. The method of claim 1, wherein providing a communications path for said first and second client nodes to the wired network includes enabling any client nodes that had been associated with said second radio to be associated with said first radio.

19. A wireless backhaul failover system having a plurality of access points operative to recover from failure of a wired link used for communication between a first one of said access points and a wired network,

a first access point having at least two radios including a first radio and a second radio each for providing a wireless communications link,

means for causing said first access point to selectively configured said radios in an access mode, each said radio in said access mode for enabling a communications path with a corresponding client node to enable each said client node to have a communication path via said first access point to the wired network, wherein said first radio is enabled to be associated with a first client node, and wherein said second radio is enabled to be associated with a second client node;

and

means for selectively reconfiguring said second radio to a backhaul mode for providing a communications path for said first and second client nodes to the wired network in response to detection of loss of the wired link to said first access point, said means for selectively reconfiguring comprising;

means for detecting said loss of the wired link to said first access point;

means for disassociating any client node from said second radio;

means for detecting a neighboring access point which can provide a link to the wired network for said first access point;

means for causing said second radio to provide a wireless link to said detected neighboring access point; and

means for causing said first access point to enable any client nodes associated with said first radio and any client nodes that had been associated with said second radio to have a communication path to the wired network via said first radio wireless link, said second radio wireless link, and said detected neighboring access point'"'"'s wired link.

20. The system of claim 19, wherein the means for detecting a neighboring access point includes;

means for causing said second radio to broadcast a request for backhaul connectivity to neighboring access points;

means for detecting whether any neighboring access point responds to said request; and

means for selecting a responding neighboring access point based on at least one predetermined criteria.

21. The system of claim 20, further comprising:

means for detecting recovery of the wired link to said first access point; and

in response thereto, selectively reconfiguring said second radio in said access mode, wherein said second radio is enabled to be associated with said second client node.