... HDDs up to 6TB, 2 USB2.0> Built-in web server, CMS(DSS/PSS) & DMSS ModelDH-NVR3204DH-NVR3208DH-NVR3216SystemMain ProcessorHigh ... , Next camera, Previous camera, Full screen, Repeat, Shuffle, Backup selection, Digital zoomBackup ModeFlash drive / USB HDD / USB CD&DVD-RW / Network ... SMTP, NTP, DHCP, DNS, IP Filter, PPPOE, DDNS, FTP, Alarm Server, IP Search(Support Dahua IP camera, DVR, NVS etc)Max ...