IP Library Granted Patent US 7,529,203
Granted Patent B2
US 7,529,203 · App. 11/139,155 · Granted May 5, 2009

Method, system and apparatus for load balancing of wireless switches to support layer 3 roaming in wireless local area networks (WLANs)

Assignee: Symbol Technologies, Inc.
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Quick Facts
Patent No.
US 7,529,203
App. No.
11/139,155
Granted
May 5, 2009
Kind
B2
Abstract

Techniques are provided for load balancing among a plurality of wireless switches configured to support a plurality of clients including a first client. An initial home wireless switch can be configured to initially support the first client. The initial home wireless switch can select one of the wireless switches as a new home wireless switch for the first client. These techniques can be implemented, for example, in a wireless local area network.

Claims (29)

1. A wireless local area network, comprising:

a plurality of clients including a first client;

a plurality of access points including a first access point; and

a mesh network of wireless switches each being directly coupled to an access point and each being coupled to each of the other wireless switches via an IP tunnel, wherein each of the wireless switches in the mesh network of wireless switches is configured to: monitor traffic being tunneled to and from the wireless switch, generate a traffic load record (TLR) comprising traffic load information for clients associated with that wireless switch, and transmit the TLR to the registration server;

a registration server, coupled to each of the wireless switches via IP tunnels, and configured to: receive the TLRs from each of the wireless switches, generate a network load report (NLR) comprising traffic load information for each of the wireless switches, and send the NLR to each of the wireless switches,

wherein the mesh network of wireless switches comprises:

a plurality of candidate wireless switches each being directly coupled to at least one access point; and

an initial home wireless switch directly coupled to the first access point, and being configured to support the first client such that the first client communicates with the initial home wireless switch via the first access point, wherein the initial home wireless switch is configured to determine, based on the NLR when traffic at the initial home wireless switch exceeds a predefined traffic load threshold (TLT), which of the candidate wireless switches is currently handling the least amount of traffic, and to select the one of the candidate wireless switches that is currently handling the least amount of traffic as a new home wireless switch for the first client, and to tunnel traffic generated by the first client to the new home wireless switch.

2. The wireless local area network of claim 1 , wherein the initial home wireless switch selects the one of the candidate wireless switches handling the least amount of traffic based on attributes in traffic load records (TLRs) associated with each of the candidate wireless switches.

3. The wireless local area network of claim 1 , wherein the initial home wireless switch is configured to select one of the candidate wireless switches as a new home wireless switch for the first client based on the NLR and the TLRs for each wireless switch.

4. The wireless local area network of claim 1 , wherein each wireless switch maintains an active client list.

5. The wireless local area network of claim 1 , wherein the traffic load record (TLR) for each wireless switch comprises:

a first parameter which specifies the number of clients the switch supports as a home switch;

a second parameter which specifies the number of clients the switch supports as a visited switch;

a third parameter which specifies traffic volume being tunneled to the switch;

a fourth parameter which specifies traffic volume being tunneled from the switch; and

a fifth parameter which specifies traffic volume being transferred by the switch.

6. The wireless local area network of claim 1 , wherein the initial home wireless switch continuously determines which of the candidate wireless switches is to be selected as a new home wireless switch.

7. The wireless local area network of claim 1 , wherein the first client sends a DHCP request to the initial home wireless switch, and wherein the initial home wireless switch forwards the DHCP request to the candidate wireless switch selected as a new home wireless switch.

8. The wireless local area network of claim 1 , when a new client joins the WLAN and sends a DHCP request to the initial home wireless switch, wherein the initial home wireless switch redirects a DHCP request received from the new client to the candidate wireless switch selected as a home wireless switch.

9. The wireless local area network of claim 1 , further comprising:

a DHCP server, coupled to the new home wireless switch, configured to assign an IP address belonging to the new home wireless switch to the first client, and

wherein the new home wireless switch tunnels a DHCP response to the initial home wireless switch such that the initial home wireless switch becomes a visited wireless switch of the first client.

10. A method of load balancing in wireless local area network comprising a plurality of access points, a mesh network of wireless switches comprising an initial home wireless switch and a plurality of candidate wireless switches, wherein each of the wireless switches in the mesh network is coupled to the other wireless switches via IP tunnels and directly coupled to at least one access point, and a plurality of clients including a first client that communicates with the initial home wireless switch via one of the plurality of access points that is directly coupled to the initial home wireless switch, the method comprising:

generating, at each of the wireless switches, a traffic load record (TLR) and communicating the TLR to a registration server, wherein each TLR comprises traffic load information for a particular wireless switch;

generating, at the registration server based on the TLRs, a network load report (NLR) which includes traffic load information for each of the wireless switches, and sending the NLR to each of the wireless switches; and

selecting one of the candidate wireless switches as a new home wireless switch for the first client based on the NLR;

determining, by the initial home wireless switch based on the NLR, which one the candidate wireless switches is currently handling the least amount of traffic;

selecting, at the initial home wireless switch, the candidate wireless switch which is currently handling the least amount of traffic as a new home wireless switch for the first client.

Assignments (11)
AMENDED SECURITY AGREEMENT Recorded Aug 18, 2023
From: EXTREME NETWORKS, INC.; AEROHIVE NETWORKS, INC.
To: BANK OF MONTREAL
Reel/Frame 064782/0971 →
RELEASE OF SECURITY INTEREST Recorded May 1, 2018
From: SILICON VALLEY BANK
To: EXTREME NETWORKS, INC.
Reel/Frame 046051/0775 →
SECURITY INTEREST Recorded May 1, 2018
From: EXTREME NETWORKS, INC.
To: BANK OF MONTREAL
Reel/Frame 046050/0546 →
THIRD AMENDED AND RESTATED PATENT AND TRADEMARK SECURITY AGREEMENT Recorded Oct 31, 2017
From: EXTREME NETWORKS, INC.
To: SILICON VALLEY BANK
Reel/Frame 044639/0300 →
SECOND AMENDED AND RESTATED PATENT AND TRADEMARK SECURITY AGREEMENT Recorded Jul 14, 2017
From: EXTREME NETWORKS, INC.
To: SILICON VALLEY BANK
Reel/Frame 043200/0614 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 8, 2016
From: SYMBOL TECHNOLOGIES, LLC
To: EXTREME NETWORKS, INC.
Reel/Frame 040579/0410 →
AMENDED AND RESTATED PATENT AND TRADEMARK SECURITY AGREEMENT Recorded Oct 31, 2016
From: EXTREME NETWORKS, INC.
To: SILICON VALLEY BANK
Reel/Frame 040521/0762 →
RELEASE OF SECURITY INTEREST Recorded Aug 17, 2015
From: MORGAN STANLEY SENIOR FUNDING, INC.
To: SYMBOL TECHNOLOGIES, INC.
Reel/Frame 036371/0738 →
CHANGE OF NAME Recorded Jul 8, 2015
From: SYMBOL TECHNOLOGIES, INC.
To: SYMBOL TECHNOLOGIES, LLC
Reel/Frame 036083/0640 →
SECURITY AGREEMENT Recorded Oct 31, 2014
From: ZIH CORP.; LASER BAND, LLC; ZEBRA ENTERPRISE SOLUTIONS CORP.; SYMBOL TECHNOLOGIES, INC.
To: MORGAN STANLEY SENIOR FUNDING, INC. AS THE COLLATERAL AGENT
Reel/Frame 034114/0270 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded May 26, 2005
From: BAJIC, ZELJKO; HAJELA, SUJAI
To: SYMBOL TECHNOLOGIES, INC.
Reel/Frame 016642/0501 →
Continuity (1)
Related Publication 20060268765A1 · Nov 30, 2006