Wireless mesh network including resilient backhaul links and WLAN traffic local switching

• US 10,225,180 B2
• Filed: 08/14/2017
• Issued: 03/05/2019
• Est. Priority Date: 12/03/2013
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Pang, Tak Ming, Meier, Robert C., Na, Yanxin, Edward, Emburey Samrex
• Primary Examiner(s): Mered, Habte
• Application Number:
  US15/675,846
• Publication Number:
  US 20170346729A1
• Time in Patent Office: 568 Days
• CPC Class Codes: H04L 45/122 by minimising distances, e.g. by selecting a route with minimum of number of hops
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/48 Routing tree calculation
• CPC Class Codes: H04W 40/24 Connectivity information management, e.g. connectivity discovery or connectivity update
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A method is performed at a mesh access point (MAP) in a wireless mesh network including access points (APs) of a spanning tree being divided among multiple Internet Protocol (IP) subnets. The method includes receiving from a first parent AP to which the MAP is a child a first IP subnet identifier indicating the first IP subnet to which the first parent AP belongs. The method also includes obtaining a first IP address associated with the first IP subnet, roaming from the first to a second parent AP, receiving from the second parent AP a second IP subnet identifier indicating a second IP subnet to which the second parent AP belongs, determining if the first and second parent APs are both part of the same IP subnet, and determining whether to maintain connectivity with a current controller or establish connectivity to a new controller based on results of the determining.

Claims

1. A method comprising:

at a mesh access point (MAP) in a wireless mesh network including access points (APs) of a spanning tree being divided among multiple Internet Protocol (IP) subnets, each IP subnet associated with a corresponding IP subnet identifier;

establishing over a first path in the wireless mesh network connectivity to a first controller configured to provide central control of the wireless mesh network and route data traffic associated with each AP of the spanning tree to and from a wired network;

receiving from a first parent AP to which the MAP is a child a first IP subnet identifier indicating the first IP subnet to which the first parent AP belongs;

obtaining a first IP address associated with the first IP subnet;

roaming from the first parent AP to a second parent AP;

receiving from the second parent AP a second IP subnet identifier indicating a second IP subnet to which the second parent AP belongs;

determining if the first parent AP and the second parent AP are both part of the same IP subnet; and

if it is determined that the first parent AP and the second parent AP are not part of the same IP subnet, which indicates that the mesh AP has roamed from the first IP subnet to the second IP subnet;

obtaining a second IP address for use in the second IP subnet;

dropping connectivity to the first controller; and

establishing connectivity over a second path in the wireless mesh network to a second controller that is the same as the first controller.

2. The method of claim 1, further comprising, at the mesh AP:

if it is determined that the first parent AP and the second parent AP are part of the same IP subnet, which indicates that the mesh AP has roamed within the first IP subnet, maintaining connectivity to the first controller, and continuing to use the first IP address.

3. The method of claim 1,

wherein the establishing connectivity over the first path includes establishing connectivity via the Control and Provisioning of Wireless Access Points (CAPWAP) protocol.

4. The method of claim 1, wherein the obtaining the first IP address and the obtaining the second IP address each include obtaining the respective IP address using Dynamic Host Configuration Protocol (DHCP) discovery.

5. The method of claim 1,

wherein the first path and the second path are least-cost paths.

6. The method of claim 1, wherein the establishing connectivity over the second path includes establishing connectivity via the Control and Provisioning of Wireless Access Points (CAPWAP) protocol.

7. The method of claim 1, wherein the determining includes comparing the first IP subnet identifier to the second IP subnet identifier.

8. The method of claim 1, wherein the roaming from the first parent AP to the second parent AP includes sending a registration request to the second parent AP to register as a child with the second parent AP.

9. The method of claim 1, wherein the MAP is among multiple MAPs of the wireless mesh network that are linked back to one or more root APs through parent-child relationships over wireless backhaul links, and the one or more root APs have respective wired connections to a wired network, and wherein the method further comprises performing each of the receiving from the first parent AP, the obtaining the first IP address, and the receiving from the second parent AP using the wireless backhaul links.

10. An apparatus comprising:

one or more radios in a mesh access point (AP) of a wireless mesh network including access points (APs) of a spanning tree being divided among multiple Internet Protocol (IP) subnets, each IP subnet associated with a corresponding IP subnet identifier;

a memory; and

a processor coupled to the one or more radios and the memory, the processor configured to;

establish over a first path in the wireless mesh network connectivity to a first controller configured to provide central control of the wireless mesh network and route data traffic associated with each AP of the spanning tree to and from a wired network;

receive from a first parent AP to which the MAP is a child a first IP subnet identifier indicating the first IP subnet to which the first parent AP belongs;

obtain a first IP address associated with the first IP subnet;

roam from the first parent AP to a second parent AP;

receive from the second parent AP a second IP subnet identifier indicating a second IP subnet to which the second parent AP belongs;

determine if the first parent AP and the second parent AP are both part of the same IP subnet; and

if it is determined that the first parent AP and the second parent AP are not part of the same IP subnet, which indicates that the mesh AP has roamed from the first IP subnet to the second IP subnet;

obtain a second IP address for use in the second IP subnet;

drop connectivity to the first controller; and

establish connectivity over a second path in the wireless mesh network to a second controller that is the same as the first controller.

11. The apparatus of claim 10, wherein the processor is further configured to:

if it is determined that the first parent AP and the second parent AP are part of the same IP subnet, which indicates that the mesh AP has roamed within the first IP subnet, maintain connectivity to the first controller, and continue to use the first IP address.

12. The apparatus of claim 10, wherein the processor is configured to establish connectivity over the first path by establishing connectivity via the Control and Provisioning of Wireless Access Points (CAPWAP) protocol.

13. The apparatus of claim 10, wherein the first path and the second path are least-cost paths.

14. The apparatus of claim 10, wherein the processor is configured to determine by comparing the first IP subnet identifier to the second IP subnet identifier.

15. The apparatus of claim 10, wherein the processor is configured to roam from the first parent AP to the second parent AP by sending a registration request to the second parent AP to register as a child with the second parent AP.

16. The apparatus of claim 10, wherein the MAP is among multiple MAPs of the wireless mesh network that are linked back to one or more root APs through parent-child relationships over wireless backhaul links, and the one or more root APs have respective wired connections to a wired network, and wherein the processor is further configured to performing each of the operations to receive from the first parent AP, obtain the first IP address, and receive from the second parent AP using the wireless backhaul links.

17. A non-transitory processor readable medium storing instructions that, when executed by a processor, cause the processor to, at a mesh access point (MAP) in a wireless mesh network including access points (APs) of a spanning tree being divided among multiple Internet Protocol (IP) subnets, each IP subnet associated with a corresponding IP subnet identifier:

establish over a first path in the wireless mesh network connectivity to a first controller configured to provide central control of the wireless mesh network and route data traffic associated with each AP of the spanning network to and from a wired network;

receive from a first parent AP to which the MAP is a child a first IP subnet identifier indicating the first IP subnet to which the first parent AP belongs;

obtain a first IP address associated with the first IP subnet;

roam from the first parent AP to a second parent AP;

receive from the second parent AP a second IP subnet identifier indicating a second IP subnet to which the second parent AP belongs;

determine if the first parent AP and the second parent AP are both part of the same IP subnet; and

if it is determined that the first parent AP and the second parent AP are not part of the same IP subnet, which indicates that the mesh AP has roamed from the first IP subnet to the second IP subnet;

obtain a second IP address for use in the second IP subnet;

drop connectivity to the first controller; and

establish connectivity over a second path in the wireless mesh network to a second controller that is the same as the first controller.

18. The non-transitory processor readable medium of claim 17, further comprising instructions to cause the processor to:

if it is determined that the first parent AP and the second parent AP are part of the same IP subnet, which indicates that the mesh AP has roamed within the first IP subnet, maintain connectivity to the first controller, and continue to use the first IP address.

19. The non-transitory processor readable medium of claim 17, further comprising instructions to cause the processor to:

establish connectivity over the first path by establishing connectivity via the Control and Provisioning of Wireless Access Points (CAPWAP) protocol.

20. The non-transitory processor readable medium of claim 17,

wherein the first path and the second path are least-cost paths.