ONVIF is based on RTSP so, by definition, more systems will support RTSP than ONVIF.
However, ONVIF adds lots of advanced functionalities (camera configuration, authentication, VMD, PTZ control, i/o, etc.) beyond the basic streaming that RTSP supports.
The best process is:
- Try to connect / integrate via a proprietary driver between the VMS and the specific camera. This is most likely to work and work completely. If that fails, then:
- Try to connect / integrate vis ONVIF. If both officially support ONVIF, this is fairly likely to work, at least for basic streaming and camera configuration. However, if no connection can be made by ONVIF, then:
- Try RTSP as a last resort, understanding that you have to manually control and configure the camera outside of the VMS.