... alone DVR Features: 4 channels cost-effective standard DVR 4 Channel D1 real-time preview H.264 dual-stream video compression ... , camera blank, video loss Easy backup: USB devices, network download Built-in web server, Support CMS, NAT traversal ... DDNS, FTP, Alarm ServerRemote OperationMonitor, PTZ control, Playback, System setting, File download, Log informationHard DiskHard Disk1 SATA port, Max ...