TP-LINK VIGI NVR has RTSP output. It is fast and the best option to view the cameras that is in the NVR rather than connecting direct to the camera.
Here’s how to get it working.
rtsp://<NVR IP>:554/ch<Channel number>/<main or sub>/av_stream
For example:
rtsp://192.168.0.123/ch1/main/av_stream
rtsp://192.168.0.123/ch4/sub/av_stream