Features 3 lines, 6 SIP accounts, up to 3 call appearances Supported by GDMS, which provides a central interface to configure, provision, manage and monitor Grandstream devices EHS (Electronic Hook Switch) support for Plantronics, Jabra and Sennheiser headsets Full duplex speakerphone with HD audio to maximize audio quality and clarity Equipped with noise shield technology to minimize background noise Two switched autosensing 10/100/1000 Mbps Gigabit Ethernet ports with integrated PoE (GRP2604P only ) Supports 5-way audio conferencing for easy conference calls Enterprise-level protection with secure boot, dual firmware images and encrypted data storage Interchangeable faceplate for easy logo customization