QNAP Security NVR-101 (Version: 2.8.0) - Manual (Page 55)

5.3.3 File Services
You can enable SMB/ CIFS file service, Web File Manager and FTP service to access
the recorded video files. These settings are enabled by default.
If your NVR is installed behind the router, you could enable FTP port mapping, so
that users from external network can access NVR via FTP (please refer to
Appendix
F ).
Passive FTP Port Range
You can use the default port range (55536-56559) or define a port range larger than
1023. When using this function, please make sure you have opened the configured
port range on your router or firewall.
Respond with external IP address for passive FTP connection request
When passive FTP connection is in use and the NVR is configured under a router, if
the remote computer cannot connect to the NVR via WAN, you can enable this
function. By enabling this function, the FTP service replies the manually specified IP
address or automatically detects the external IP address so that the remote
computer can connect to the NVR successfully.
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