WLAN QoS Deployment Considerations

Before defining a QoS configuration on a controller, service platform or access point managed WLAN, refer to the following deployment guidelines to ensure the configuration is optimally effective:

• WLAN QoS configurations differ significantly from QoS policies configured for associated radios. WLAN QoS configurations are designed to support the data requirements of wireless clients, including the data types they support and their network permissions. Radio QoS policies are specific to the transmit and receive characteristics of the connected radio's themselves, independent from the wireless clients the radios support.
• Enabling WMM support on a WLAN only advertises WMM capability to wireless clients. The wireless clients must also support WMM and use the parameters correctly while accessing the wireless network to truly benefit.
• Rate limiting is disabled by default on WLANs. To enable rate limiting, a threshold must be defined for WLAN.
• Before enabling rate limiting on a WLAN, a baseline for each traffic type should be performed. Once a baseline has been determined, a minimum 10% margin should be added to allow for traffic bursts.
• The bandwidth required for real-time applications such as voice and video are very fairly easy to calculate because the bandwidth requirements are consistent and can be realistically trended over time. Applications such as web, database, and email are harder to estimate because bandwidth usage varies depending on how the applications are used.