Single Point Setup Overview
Single Point Setup provides a centralized method to administer and control wireless services across multiple devices. You use Single Point Setup to create a single group, or cluster, of wireless devices. After the WAP devices are clustered, you can view, deploy, configure, and secure the wireless network as a single entity. After a wireless cluster is created, Single Point Setup also facilitates channel planning across your wireless services to reduce radio interference and maximize bandwidth on the wireless network.
When you first set up your WAP device, you can use the Setup Wizard to configure Single Point Setup or join an existing Single Point Setup. If you prefer not to use the Setup Wizard, you can use the web-based configuration utility.
Managing Single Point Setup Across Access Points
Single Point Setup creates a dynamic, configuration-aware cluster, or group, of WAP devices in the same subnet of a network. A cluster supports a group of up to 16 configured WAP371 devices, but no other non-WAP371 models in the same cluster.
Single Point Setup allows the management of more than one cluster in the same subnet or network; however, they are managed as single independent entities. The table shows Single Point Setup wireless service limits.
A cluster can propagate configuration information, such as VAP settings, QoS queue parameters, and radio parameters. When you configure Single Point Setup on a device, settings from that device (whether they are manually set or set by default) are propagated to other devices as they join the cluster. To form a cluster, make sure the following prerequisites or conditions are met:
- Plan your Single Point Setup cluster. Be sure the two or more WAP devices you want to cluster are compatible with each other. For example, Cisco WAP371 devices can only cluster with other Cisco WAP371 devices.
NOTE It is strongly recommended to run the latest firmware version on all clustered WAP devices. Firmware upgrades are not propagated to all WAP devices in a cluster; you must upgrade each device independently.
- Set up the WAP devices that will be clustered on the same IP subnet and verify that they are interconnected and accessible across the switched LAN network.
- Enable Single Point Setup on all WAP devices. See Access Points.
- Verify that the WAP devices all reference the same Single Point Setup name. See Access Points.
Single Point Setup Negotiation
When a AP is enabled and configured for Single Point Setup, it begins sending periodic advertisements every 10 seconds to announce its presence. If there are other WAP devices that match the criteria for the cluster, arbitration begins to determine which WAP device will distribute the master configuration to the rest of the members of the cluster.
The following rules apply to Single Point Setup cluster formation and arbitration:
- For existing Single Point Setup clusters, whenever the administrator updates the configuration of any member of the cluster, the configuration change is propagated to all members of the cluster, and the configured WAP device assumes control of the cluster.
- When two separate Single Point Setup clusters join into a single cluster, then the latest modified cluster wins arbitration of the configuration and overwrites and updates the configuration of all clustered WAP devices.
- If a WAP device in a cluster does not receive advertisements from a WAP device for more than 60 seconds (for example, if the device loses connectivity to other devices in the cluster), the device is removed from the cluster.
- If a WAP device in Single Point Setup mode loses connectivity, it is not immediately dropped from the cluster. If it regains connectivity and rejoins the cluster without having been dropped, and configuration changes were made to that device during the lost connectivity period, the changes are propagated to the other cluster members when connectivity resumes.
- If a WAP device in a cluster loses connectivity, is dropped, later rejoins the cluster, and configuration changes were made in the during the lost connectivity period, the changes are propagated to the device when it rejoins. If there are configuration changes in both the disconnected device and the cluster, then the device with the greatest number of changes and, secondarily, the most recent change, will be selected to propagate its configuration to the cluster. (That is, if WAP1 has more changes, but WAP2 has the most recent change, WAP1 is selected. If they have an equal number of changes, but WAP2 has the most recent change, then WAP2 is selected.)
Operation of a Device Dropped From a Single Point Setup
When a WAP device that was previously a member of a cluster becomes disconnected from the cluster, the following guidelines apply:
- Loss of contact with the cluster prevents the WAP device from receiving the latest operational configuration settings. The disconnection results in a halt to proper seamless wireless service across the production network.
- The WAP device continues to function with the wireless parameters that it last received from the cluster.
- Wireless clients associated with the non-clustered WAP device continue to associate with the device with no interruption of the wireless connection. In other words, loss of contact with the cluster does not necessarily prevent wireless clients associated with that WAP device from continued access to network resources.
- If the loss of contact with the cluster is due to a physical or logical disconnect with the LAN infrastructure, network services out to the wireless clients may be impacted depending on the nature of the failure.
The tables summarize configurations that are shared and propagated among all clustered WAP devices.
Configuration Parameters Propagated and Not Propagated to Single Point Setup Access Points
Radio Configuration Settings and Parameters that are Not Propagated in Single Point Setup
Channel
Beacon Interval
DTIM Period
Maximum Stations
Transmit Power