ONVIF secures device discovery and basic video transport, but vendor implementations differ, so in practice you often see 'video works but audio does not' or 'analytics unavailable'.

1. Confirm ONVIF is enabled: the camera needs a dedicated ONVIF user — not the regular login — plus ONVIF switched on with the required profile version in its protocol settings.
2. Add it manually: automatic discovery often misidentifies devices. Enter the IP, port (commonly 80 or 8000), credentials and RTSP path by hand.
3. Match the ONVIF profile: Profile S covers video only. Audio and events require Profile T or G, so a version mismatch shows up as missing features.
4. Time and authentication: if device and recorder clocks differ by more than about five minutes, authentication fails and presents as a wrong-password loop. Sync by NTP and retry.

Where interoperability still fails, fall back to a generic RTSP path for video. Analytics, however, generally need to stay within one vendor's ecosystem or be unified at the platform layer.