If Currently Active Session Count is much higher than Currently Active Session Count with Active Presence Subscriptions, this indicates that more users are using a background endpoint device, such as an Apple iOS device or Windows Phone under Mcx. UCWA always-connected devices include Apple and Android devices running Lync 2013 Mobile clients). If the difference between Currently Active Session Count with Active Presence Subscriptions and Currently Active Session Count is small over time, this means that most mobile device users have an always-connected device, such as an Android or Nokia mobile device (for Mcx only). The counters to monitor are:Ĭurrently Active Session Count with Active Presence Subscriptions, which is the current number of endpoints registered through UCWA or the Mobility Service (Mcx) that have active presence subscriptions (number of always-connected mobile users)Ĭurrently Active Session Count, which is the current number of endpoints registered through UCWA or the Mobility Service For the Mobility Service (Mcx), the counters are under the category LS:WEB - Mobile Communication Service. For UCWA, the counter category is LS:WEB - UCWA. Two mobility performance counters can help you to determine your current usage and help you plan capacity for the Skype for Business Server Mobility Service (Mcx), as well as to monitor memory usage for UCWA.

Users with legacy clients using MCX will need to upgrade to a current client. All current Skype for Business mobile clients already use Unified Communications Web API (UCWA) to support instant messaging (IM), presence, and contacts. MCX (Mobility Service) support for legacy mobile clients is no longer available in Skype for Business Server 2019.

Skype for business recording limits