What is the difference between stream from the network camera and server?
Stream from the network camera
The monitoring screens are streamed from the network cameras. When your network surveillance system (VioStor NVR), IP cameras, and PC are installed behind the router, virtual server, or firewall, you will have to configure port forwarding (port mapping) for some of the IP cameras. Please refer to http://www.qnapsecurity.com/Applications_nvrig.asp
Stream from the server
The monitoring screens are streamed from the video server. There is no need to configure port mapping. However, the VioStor NVR performance may be affected. You may have to adjust the recording settings according to the real performance.