The latest challenge confronting IT organizations is managing the influx of mobile devices and real-time that rely on the enterprise LAN. The WLAN has to be resilient enough to enable mobile devices to stay connected and applications like voice and to work without interruption.
To increase resiliency in any network infrastructure, it's good to start by employing a network design ready for high availability. But designing for high availability is not always enough to ensure WLANs are ready for mission-critical applications.
In wired access networks, we hardly worry about the user devices disconnecting from the network in case of a network failure, because the cable always stays connected as recovery takes place within the redundancy infrastructure. With WLANs this can be a challenge because traditional wireless access points (APs) turn off their Wi-Fi radios during a and mobile devices then start to search for a new AP.
So the easiest way to achieve a wired-like resiliency for WLANs is to not give mobile devices any chance to roam -- that is, to never drop them off the Wi-Fi network until WLAN recovery is complete. To achieve this, wireless APs should continue to broadcast SSIDs so mobile devices won't resort to scanning for other APs or SSIDs to connect to. This greatly reduces the possibility that a mobile device will disconnect from the network.