This is the interval at which the node gathers and prints billing records specifically for permanent virtual circuits, PVCs, that have billing enabled. Unlike the call-based billing threshold and timer objects above, which apply to switched calls, this governs a separate periodic billing cycle for always-on PVC connections, since PVCs don't generate discrete call-detail events the way dialed calls do. For example, setting this to 1440, the number of minutes in a day, would gather and print PVC billing records once daily rather than continuously.