4ch video server,digital video server,network server,ip video server H.264 built ... time transmission of audio talk-back &broadcast.l Network self-adapting technology to adjust video frame rate automatically ... DDNS, DNS, DHCP, UPnP(CP for NAT)System Interface Built in SD card10M/100M self-adapting Ethernet port, 1 ... 5.x or above 4ch video server,digital video server,network server,ip video server