The design of i21/i21T SIP Door phone is based on experience and knowledge of Fanvil IP phone development. i21/i21T use standard IP/RTP/RTSP protocol for voice transmission and enjoy the advantages of full range of compatibility. i21/i21T have a variety of enterprise-level features and compatible with lots of major platforms, such as 3CX, Asterisk, Broadsoft, Elastix, etc.
Outdoor equipment is often being damage by water, hit, slurry, etc. In order to protect the door phones from damage,i21/i21T are made of the high strength stainless steel with cast iron button and have non-removable hexagon screw to protect the surface shell from being removed. This structure can effectively prevent the i21/i21T from raining, water spraying, dust and reduce man-made damage. Its impact resistant level is up to Ik10 standard. Besides, its water-proof and dust-proof level is up to IP65.