See PBX.

1. A subscriber-owned telecommunications exchange that usually includes access to the public switched network.
2. A switch that serves a selected group of users and that is subordinate to a switch at a higher level military establishment.
3. A private telephone switchboard that provides on-premises dial service and may provide connections to local and trunked communications networks.
Note 1: A… (Read More →)

A private telecommunication switch that usually includes access to the public switched network.

1. In a public-key cryptosystem, that key of a user's key pair which is known only to that user. [After X9.42]
2. A cryptographic key created and kept private by a party.
Note: A private key may be used for the following: to compute the corresponding public key; to make a digital signature which may be verified by the corresponding… (Read More →)

1. In telephone industry usage, a service that involves dedicated circuits, private switching arrangements, predefined transmission paths, or combination thereof, whether virtual or physical, and which provide communications between specific locations.
2. Among subscribers to the public switched telephone network(s), a one-party switched access line.

1. A service for communications between specified locations for a continuous period or for regularly recurring periods at stated hours. [47 CFR Pt.36-A]
2. A service whereby facilities for communication between two or more designated points are set aside for the exclusive use or availability for use of a particular customer and authorized users during stated periods of time. [47CFR]

Private networks are composed of stations which are not directly accessible from all PSTN stations via the use of NANP E.164 numbers.

Non-common-carrier telecommunications services, including private line, virtual private line, and private switched network services.

In cryptographic applications, the two prime numbers, namely p and q, whose product pq is the modulus n. [After X9.31]

The ability to exercise a controlled or restricted service [POSIX.6].