The features “Toggle”, “Hold” and “Consult” are interrelated and are used when two callers wish to converse with a third party. When another caller is trying to make contact while a telephone conversation is in progress, this may be indicated by a knocking tone, for example. The called party can inform the “knocking” caller by means of the “Consult” function that he will ring him back shortly. The original caller is placed on hold during this time. Once the conversation with the “knocking” caller has ended, the “consulting” party automatically returns to the caller on hold and the call can be continued normally. Toggling allows the user to switch to and fro between two callers any number of times. Inactive callers are placed in a call queue. The conference function permits three or more parties to be interconnected for a conference call. In this case, all parties are able to communicate with each other in a virtual chat room.
The number of lines occupied varies depending on whether the feature is made available in the network or the telephone system. Toggling via the telephone system generally occupies two outgoing lines connected to the public telephone network, whereas toggling within the telephone exchange is possible with only one active phone line. All modern telephone systems, including cloud telephone systems, support features such as toggling, holding or consulting and offer a wide range of convenient conference functions.