This section lists recommendations to optimize WLAN to support voice deployment.
For best results, use Wi-Fi Certified (voice enterprise certification from Wi-Fi Alliance) AP models.
If SSID for voice is enabled on 2.4G band, do not enable the 11b-legacy data rates on that band unless specifically required by some restricted coverage planning or older legacy devices must be supported.
The device chooses to roam or connect to an AP depending on the infrastructure settings in effect and the underlying dynamics of the RF ecosystem. Generally, the device scans for other available APs at certain trigger points (for example, if the connected AP is weaker than -65 dBm) and connects to a stronger AP if available.
802.11r: Zebra strongly recommends that the WLAN network supports 11r FT as a fast-roaming method to achieve the best WLAN and device performance and user experience.
11r is recommended above other fast-roaming methods, including any vendor-proprietary methods, such as Cisco centralized key management (CCKM).
When the 11r is enabled on the network, either with pre-shared-key (PSK) security (such as FT-PSK) or with an authentication server (such as FT-802.1x), the Zebra device automatically facilitates 11r, even if other parallel non-11r methods co-exist on the same SSID network. No configuration is needed.
Disable unused Fast Roam Methods from the SSID if possible. However, if older devices on the same SSID support a different method, that two or more methods may remain enabled if they can coexist. The device automatically prioritizes its selection per the Fast Roaming Method in Table 5.
It is a general best practice to limit the amount of SSID per AP to only those required. There is no specific recommendation on the number of SSIDs per AP as this depends on multiple RF environmental factors which are specific to each deployment. A high number of SSIDs impacts channel utilization which comprises not only users and application traffic, but also beacons traffic of all SSIDs on the channel, even those not in use.
Call Admission Control (CAC):
The network's CAC feature is designed to facilitate VoIP deployments, but uses algorithmic complexities to determine whether to accept or reject new calls based on network resources in runtime.
Do not enable (set to mandatory) CAC on the controller without testing and validating the stability of admissions (calls) in the environment under stress and plurality conditions.
Be aware of devices that do not support CAC which are using the same SSID as Zebra devices support CAC. This scenario requires testing to determine how the network CAC impacts the entire eco-system.
If WPA3 is required for the deployment, refer to the Zebra WPA3 Integrator Guide for guidance on device models that support WPA3 and configuration guidance.
