A company has a single WLAN configured for 802.1x authentication with the QoS set to Silver. This WLAN supports all corporate and BYOD access. A decision has been made to allow users to install Cisco Jabber on their personal mobile devices. Users report poor voice quality when using Jabber. QoS is being applied only as best effort. What must be configured to ensure that the WLAN remains on the Silver class and to ensure Platinum class for Jabber?