The viewerframe component of a camera’s URL is the dedicated web interface used to display the live video feed. When you access a camera via a browser, you aren't just looking at a raw video file; you are interacting with a frame that handles the handshake between the camera’s hardware and your display.
It instructs the camera to bypass thumbnails or resized "mobile" versions and deliver the maximum available resolution for each refreshed frame. viewerframe mode refresh full
The full suffix generally refers to the resolution or the interface layout. The viewerframe component of a camera’s URL is
The parameters following the question mark ( ? ) tell the camera exactly how to behave. Breaking Down "Mode=Refresh" viewerframe mode refresh full
Understanding "viewerframe mode refresh full": Optimizing IP Camera Monitoring