Hello @alangt 

Here is guide introducing different methods to view NC camera: How to view the Camera?

- If camera has connected to home Wi-Fi network and gets an IP address, you should be able to watch live view through tpCamera APP when phone under the same local network That requires to connect mobile phone to the home Wi-Fi network ( turn off VPN or mobile data on the phone )

- if you try to login web UI of camera using its IP address on a mobile device , please also make sure the phone is connected to home Wi-Fi network ( turn off VPN or mobile data on the phone ) . You could try a different browser if certain browser reports error. 

 Hello  @alangt 

As far as I know the APP does require log in, but not every time.  You could try to log in APP first before internet stops.  Give that a try and let us know how it goes. 

NC cameras also support RTSP streaming,  you could download an APP which supports RSTP and try to set up a connection: 

RTSP streaming port: 554

For NC220/NC230/NC250/NC260/NC450:

720P: rtsp://admin:Password@IP:554/h264_hd.sdp

480P: rtsp://admin:Password@IP:554/h264_vga.sdp

Note: Here Password is the login password you set for the camera.