The Z 21i is an easy-to-use, cost-eff­ective business IP phone with a graphical backlit display, dedicated line keys, and Power over Ethernet (PoE) support. A dedicated headset port and Electronic Hook Switch (EHS) support off­er enhanced usability for wired and wireless headset users. The Z 21i is fully compatible with Zultys’ ZAC Unified Communications application, allowing users to manage calls and messages directly from their computers. Like all Zultys phones, the Z 21i utilizes the Session Initiation Protocol (SIP) open standard. It is managed from the Zultys MX Administrator application for rapid deployment and the industry’s lowest total cost of ownership.