This read-only Gauge accumulates the total charging units applied to this peer device since the row was created, counting only units attributable to the local interface, such as originated calls or calls with reverse charging active. An admin monitors this to track usage-based billing exposure for dial connections to a specific peer. For example, a rapidly climbing ctDAWanDeviceChargedUnits value on one peer entry compared to others could indicate that peer is being called far more often, driving up telecom charges.