Grandstream GXV3504 IP Video Encoder 4 Analog video inputs (BNC) and 4 alarm input & outputs Audio input and output, RS485/232, PTZ control 24MB pre-/post-event recording buffer per port Integrated Power-over-Ethernet (802.3af), optional antenna for wireless network SIP/VoIP support for two-way audio communications and video streaming to mobile phones and video phones