1. General

1.1 Definition and legal status

The term "private branch exchange" refers to all the equipment made available to a group of people - the users - to enable them to communicate effectively with each other and with other people connected to external networks.

Under telecommunications regulations, private telephone installations serve people belonging to the same legal entity: a company or an administration, and located at one or more clearly identified sites. As a result, communications established internally by a private telephone system are not subject to the restrictions resulting from the State's monopoly on communications. The concept of a private branch exchange therefore has a legal delimitation which, until telecommunications regulations underwent a major...