In a large hotel, where the switchboard is situated in a telephone room, the volume of the work will determine the number of operators required on duty at any time. Their duties include receiving all incoming calls and connecting them with the required extensions. As soon as the incoming call is answered by the operator, the caller commences to be charged, therefore prompt attention and a speedy connection are imperative. If the required extension is engaged, the caller should be invited to “hold the line”, “ring back”, or “leave a message”. Modern switchboards enable guests either to dial their own local calls themselves or to obtain them through the hotel operator. When the guest dials the call personally, it is automatically recorded and metered on a mater panel in the bills office. The telephone charges are then posted to the guest’s account and the meter resets to zero. If a guest wish to send a telegram over the telephone, this will have to be done via the hotel operator so that she or he can record the charges, which cannot be done by the meter. In most hotels using this type of switchboard, guests, by direct dialing, are able to telephone each other’s room without going through the hotel operator. Likewise, hotel services (reception, housekeeper, floor service, etc.) can be dialed directly. The use of this type of switchboard helps to relieve the pressures on the hotel telephone operator and speeds up telephone calls as most of the time the hotel operator only needs to connect incoming calls.