Unified Call Manager, also known as Unified Communications Manager (UCM), is a software-based call processing system developed by Systems. UCM is mainly used in enterprise environments and large organizations to manage and control their IP-based telephony network. It enables businesses to set up, manage, and control voice and video calls, voicemail, conferencing, mobility features, and other communication services across various endpoints, including IP phones, softphones, video endpoints, and mobile devices.