Answer:
ANR stands for Automatic Network Replenishment and refers to what should happen when there is any disruption in the network connection between an IPC with a built-in SD card and the NVR. If ANR is enabled, when such a disruption occurs, the IPC will save its recordings to the camera’s SD card. Once the network is restored, the video recordings will be sent from the camera’s SD card to NVR’s storage.