PABX |
Private Automatic Branch Exchange. A private branch exchange (PBX) that provides access to and from the public telephone network without operator intervention. |
PBX |
Private Branch Exchange. A switching system providing telephone communications between internal stations and external networks. |
PCM |
Pulse Code Modulation. |
physical extension |
is associated with a physical port and device. An extension is created, by default, as a physical extension (as opposed to a virtual or workgroup extension) unless there are no more physical ports available. |
pilot number |
the extension number that identifies a workgroup or distribution group. |
POP3 |
Post Office Protocol version 3. Protocol for retrieving email by remote client. |
port |
a communication channel through which a client process communicates with a protected subsystem. |
POSIX |
an acronym defined as “a portable operating system interface based on UNIX,” refers to a collection of international standards for UNIX-style operating system interfaces. In the mid-to-late 1980’s, government agencies began specifying POSIX as a procurement standard for government computing contracts. |
Power Failure Backup |
If your AC power fails, your telephone system can still operate by switching to a backup battery power supply, often called an (Uninterrupted Power Supply) UPS. |
Power Failure Transfer |
A telephone system feature. When the commercial AC power fails and there is no backup power source such as a battery or a generator, this feature switches some of the trunks connected to the telephone system to several single line phones that do not need external power and can draw their power from the telephone lines. |
Power Supply |
the part of the telephone system or a computer that converts the normal 120 or 240 volts AC power to AC and DC at the various voltages and frequencies as needed by various components and circuits of the system. |
Private Network |
A series of offices connected together by leased and non-leased telephone lines, with switching facilities and transmission equipment owned and operated by the user or by the carrier and leased to the user |
Protected subsystems |
integral subsystems that perform important operating system functions, such as security subsystems among others. |
protocol |
A set of rules and conventions by which two computers pass messages across a network medium. Networking software generally implements multiple levels of protocols layered one on top of the other. |
