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

• US 9,769,063 B2
• Filed: 06/06/2016
• Issued: 09/19/2017
• 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:
  US15/174,037
• Publication Number:
  US 20160285751A1
• Time in Patent Office: 470 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 wireless mesh network includes mesh access points (mesh APs) and a root access point (RAP) forming a root of a tree of the mesh APs in which the mesh APs are linked back to the RAP through parent-child relationships over wireless backhaul links. A mesh AP provides access to the mesh network via connections to wireless clients in one or more wireless local area networks (WLANs) served by the mesh AP. The mesh AP stores mappings between the one or more WLANs served by the mesh AP and one or more virtual local area networks (VLANs) configured on a wired network and to which the WLANs are assigned. The mesh AP receives mappings between the VLANs configured on the wired network and WLANs served by the mesh AP as known by the RAP. If the stored mappings and the received mappings differ, the mesh AP updates the stored mappings with the received mappings that differ from the stored mappings.

Claims

1. A method comprising:

at a mesh access point (AP) in a wireless mesh network including a plurality of mesh access points and a root AP forming a root of a tree of the mesh APs in which the mesh APs are linked back to the root AP through parent-child relationships over wireless backhaul links, the root AP having a connection to a wired network;

providing access to the mesh network via wireless connections to wireless clients in one or more wireless local area networks (WLANs) served by the mesh AP;

storing mappings between the one or more WLANs served by the mesh AP and one or more virtual local area networks (VLANs) configured on the wired network and to which the WLANs are assigned;

receiving, from a parent access point of the mesh AP, mappings between the VLANs configured on the wired network and WLANs served by the mesh AP as known by the root AP; and

if the stored mappings and the received mappings differ, updating the stored mappings with the received mappings that differ from the stored mappings so that the stored mappings reflect the mappings known by the root AP.

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

receiving, from a child AP of the mesh AP, mappings between one or more WLANs served by the child AP and one or more of the VLANs; and

sending the mappings received from the child AP to the parent AP to be forwarded to the root AP.

3. The method of claim 2, wherein, from the perspective of the root AP, the mappings between the one or more WLANs served by the mesh AP and the one or more VLANs configured on the wired network include the mappings between the one or more WLANs served by the child AP and the VLANs configured on the wired network.

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

discovering a new parent AP to which to roam;

sending to the new parent AP a registration request destined for the root AP, the registration request configured to register the mesh AP as a child AP to the new parent AP and including the stored mappings;

in response to sending the registration request, receiving from the parent AP a registration response originated at the root AP and that includes the mappings as known to the root AP; and

if the stored mappings and the mappings in the received registration response are different, performing the updating.

5. The method of claim 1, wherein the mappings between the one or more WLANs served by the mesh AP and the one or more virtual local area networks (VLANs) configured on the wired network include a mesh AP identifier and a mesh AP media access control (MAC) address that are each mapped to a list of the one or more WLANs, which are in turn mapped to the one or more VLANs.

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

while the mesh AP is connected to a controller of the mesh network through which traffic to and from the wireless mesh network is normally routed from and to the wired network, advertising to each child AP of the mesh AP a respective actual path-cost leading back to the root AP; and

detecting a loss of connectivity to the controller and, in response thereto, advertising to each child AP an artificially reduced path-cost that is less than the respective actual path cost so as to inhibit each child AP from roaming to a different parent AP during the loss of connectivity.

7. The method of claim 6, further comprising, at the mesh AP, if connectivity with the controller is detected, advertising to each child AP the respective actual path-cost.

8. The method of claim 1, further comprising, at the root AP:

storing in the root AP mappings of one or more WLANs to one or more VLANs configured on the wired network for each of the root AP and all descendent mesh APs of the root AP; and

updating the mappings stored in the root AP for each of the root AP and all descendent mesh APs of the root AP based on changes to the VLANs configured on the wired network.

9. The method of claim 8, further comprising, at the root AP:

sending the mappings stored in the root AP to all of the descendent mesh APs of the root AP;

receiving respective mappings from each of the descendent mesh APs of the root AP; and

updating the mappings stored in the root AP for each of the descendent mesh APs based on the respective mappings from all of the descendent mesh APs.

10. An apparatus comprising:

one or more radios in a mesh access point (AP) configured to communicate over backhaul links of a wireless mesh network including a plurality of mesh APs and a root AP forming a root of a tree of the mesh APs in which the mesh APs are linked back to the root AP through parent-child relationships over wireless backhaul links, the root AP having a connection to a wired network;

a memory; and

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

provide access to the mesh network via wireless connections to wireless clients in one or more wireless local area networks (WLANs) served by the mesh AP;

store mappings between the one or more WLANs served by the mesh AP and one or more virtual local area networks (VLANs) configured on the wired network and to which the WLANs are assigned;

receive, from a parent access point of the mesh AP, mappings between the VLANs configured on the wired network and WLANs served by the mesh AP as known by the root AP; and

if the stored mappings and the received mappings are different, update the stored mappings with the received mappings that are different from the stored mappings so that the stored mappings reflect the mappings known by the root AP.

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

receive, from a child AP of the mesh AP, mappings between one or more WLANs served by the child AP and one or more of the VLANs; and

send the mappings received from the child AP to the parent AP to be forwarded to the root AP.

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

discover a new parent AP to which to roam;

send to the new parent AP a registration request destined for the root AP, the registration request configured to register the mesh AP as a child AP to the new parent AP and including the stored mappings;

in response to sending the registration request, receive from the parent AP a registration response originated at the root AP and that includes the mappings as known to the root AP; and

if the stored mappings and the mappings in the received registration response are different, perform the update operation.

13. The apparatus of claim 10, wherein the mappings between the one or more WLANs served by the mesh AP and the one or more virtual local area networks (VLANs) configured on the wired network include a mesh AP identifier and a mesh AP media access control (MAC) address that are each mapped to a list of the one or more WLANs, which are in turn mapped to the one or more VLANs.

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

while the mesh AP is connected to a controller of the mesh network through which traffic to and from the wireless mesh network is normally routed from and to the wired network, advertise to each child AP of the mesh AP a respective actual path-cost leading back to the root AP; and

detect a loss of connectivity to the controller and, in response thereto, advertise to each child AP an artificially reduced path-cost that is less than the respective actual path cost so as to inhibit each child AP from roaming to a different parent AP during the loss of connectivity.

15. The apparatus of claim 14, wherein the processor is further configured to, if connectivity with the controller is detected, advertise to each child AP the actual path-cost.

16. A non-transitory tangible processor readable medium storing instructions that, when executed by a processor, cause the processor to, at a mesh access point (AP) in a wireless mesh network including a plurality of mesh APs and a root AP forming a root of a tree of the mesh APs in which the mesh APs are linked back to the root AP through parent-child relationships over wireless backhaul links, the root AP having a connection to a wired network:

provide access to the mesh network via wireless connections to wireless clients in one or more wireless local area networks (WLANs) served by the mesh AP;

store mappings between the one or more WLANs served by the mesh AP and one or more virtual local area networks (VLANs) configured on the wired network and to which the WLANs are assigned;

receive, from a parent access point of the mesh AP, mappings between the VLANs configured on the wired network and WLANs served by the mesh AP as known by the root AP; and

if the stored mappings and the received mappings are different, update the stored mappings with the received mappings that are different from the stored mappings so that the stored mappings reflect the mappings known by the root AP.

17. The non-transitory processor readable medium of claim 16, further comprising instructions to cause the processor to:

receive, from a child AP of the mesh AP, mappings between one or more WLANs served by the child AP and one or more of the VLANs; and

send the mappings received from the child AP to the parent AP to be forwarded to the root AP.

18. The non-transitory processor readable medium of claim 16, further comprising instructions to cause the processor to:

discover a new parent AP to which to roam;

send to the new parent AP a registration request destined for the root AP, the registration request configured to register the mesh AP as a child AP to the new parent AP and including the stored mappings;

in response to sending the registration request, receive from the parent AP a registration response originated at the root AP and that includes the mappings as known to the root AP; and

if the stored mappings and the mappings in the received registration response are different, perform the update operation.

19. The non-transitory processor readable medium of claim 16, wherein the mappings between the one or more WLANs served by the mesh AP and the one or more virtual local area networks (VLANs) configured on the wired network include a mesh AP identifier and a mesh AP media access control (MAC) address that are each mapped to a list of the one or more WLANs, which are in turn mapped to the one or more VLANs.

20. The non-transitory processor readable medium of claim 16, further comprising instructions to cause the processor to:

while the mesh AP is connected to a controller of the mesh network through which traffic to and from the wireless mesh network is normally routed from and to the wired network, advertise to each child AP of the mesh AP a respective actual path-cost leading back to the root AP; and

detect a loss of connectivity to the controller and, in response thereto, advertise to each child AP an artificially reduced path-cost that is less than the respective actual path cost so as to inhibit each child AP from roaming to a different parent AP during the loss of connectivity.