3 lines, 6 SIP accounts, up to 3 call appearances, Supported by GDMS which provides a centralized interface to configure, provision, manage and monitor Grandstream devices, Electronic Hook Switch (EHS) 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, Dual switched autosensing 10/100/1000 Mbps Gigabit Ethernet