Optimized Roaming

Optimized Roaming

Optimized roaming resolves the problem of sticky clients that remain associated to access points that are far away and outbound clients that attempt to connect to a Wi-Fi network without having a stable connection. This feature disassociates clients based on the RSSI of the client data packets and data rate. The client is disassociated if the RSSI alarm condition is met and the current data rate of the client is lower than the optimized roaming data rate threshold. You can disable the data rate option so that only RSSI is used for disassociating clients.

Optimized roaming also prevents client association when the client's RSSI is low. This feature checks the RSSI of the incoming client against the RSSI threshold. This check prevents the clients from connecting to a Wi-Fi network unless the client has a viable connection. In many scenarios, even though clients can hear beacons and connect to a Wi-Fi network, the signal might not be strong enough to support a stable connection.

You can also configure the client coverage reporting interval for a radio by using optimized roaming. The client coverage statistics include data packet RSSIs, Coverage Hole Detection and Mitigation (CHDM) pre-alarm failures, retransmission requests, and current data rates.

Optimized roaming is useful in the following scenarios:

  • Addresses the sticky client challenge by proactively disconnecting clients.

  • Actively monitors data RSSI packets.

  • Disassociates client when the RSSI is lower than the set threshold.

This section contains the following subsections:

Restrictions for Optimized Roaming

  • You cannot configure the optimized roaming interval until you disable the 802.11a/b network.

  • When basic service set (BSS) transition is sent to 802.11v-capable clients, and if the clients are not transitioned to other BSS before the disconnect timer expires, the corresponding client is disconnected forcefully. BSS transition is enabled by default for 802.11v-capable clients.

  • The Cisco Catalyst 9800 controller increments the 80211v smart roam failed counter while disconnecting the client due to optimized roaming.

  • We recommend that you do not use the optimized roaming feature with RSSI low check.

Configuring Optimized Roaming (GUI)

Procedure

Step 1

Choose Configuration > Wireless > Advanced.

Step 2

On the Advanced page, click the relevant band's tab: either 5 GHz Band or 2.4 GHz Band.

Step 3

Check the Optimized Roaming Mode check box to enable the feature.

Step 4

Choose the required Optimized Roaming Date Rate Threshold. The threshold value options are different for 802.11a and 802.11b networks.

Optimized roaming disassociates clients based on the RSSI of the client data packet and data rate. The client is disassociated if the current data rate of the client is lower than the Optimized Roaming Data Rate Threshold.

Step 5

Click Apply to save the configuration.

Configuring Optimized Roaming (CLI)

Procedure

  Command or Action Purpose

Step 1

ap dot11 5ghz rrm optimized-roam

Configures 802.11a or 802.11b optimized roaming.

By default, optimized roaming is disabled.

Step 2

ap dot11 5ghz rrm optimized-roam reporting-interval interval-seconds

Configures the client coverage reporting interval for 802.11a or 802.11b networks.

The range is from 5 to 90 seconds. The default value is 90 seconds.

Note

 

You must disable the 802.11a network before you configure the optimized roaming reporting interval.

The access point sends the client statistics to the controller based on the following conditions:

  • When the reporting-interval interval-seconds is set to 90 seconds by default.

  • When the reporting-interval interval-seconds is configured (for instance to 10 secs) only during optimized roaming failure due to the Coverage Hole Detection (CHD) RED ALARM.

Step 3

ap dot11 5ghz rrm optimized-roam data-rate-threshold mbps

Configure the threshold data rate for 802.11a networks.

For 802.11a, the configurable data rates are 1, 2, 6, 9, 12, 18, 24, 36, 48, and 54. You can configure DISABLE to disable the data rate.

Step 4

show wireless statistics ap dot11 5ghz optimized-roaming statistics

Displays optimized roaming statistics for each band.