| 摘要 |
<p>A UIFN toll free service is provided and controlled by control units 11 and 12 that communicate with each other using a separate data network. The control units arrange the connection of calls on a telephone network. The calls are monitored and billing created for appropriate UIFN customers by the control units. In one embodiment, each call is established by a TNO control unit, as if the customer had initiated the toll free call. Such calls are then treated automatically, especially for billing, as normal IDD calls made by the TNO customer. <IMAGE></p> |
