Glossary of Terms

P-S

P

Packet switching - A data communications technique where the data is broken down into fixed-length units (packets) which are then transmitted to their destination through the fastest route. The receiving station ensures that all units are received and are in proper sequence before forwarding the data to an addressee.

PBX - Private Branch Exchange
A telephone system where incoming calls are mainly answered by an attendant who offers those calls to the required extension. (May also be called PABX).

PCMCIA - Personal computer memory card international association.

Point and click - A process whereby the user moves their mouse until the pointer on the screen reaches the desired button or control on the screen. The mouse is clicked to initiate the activity associated with that button or control.

POT - Plain Ordinary Telephone

PRI - Primary Rate Interface
Access to the ISDN service at 2.048Mbps in Europe (known as 30B+D) and 1.544Mbps in the US, Japan and Canada (known as 23B+D).

Private circuits - Dedicated telecommunications links between nodes.

Private network - A communication network designed and operated for the exclusive use of a particular organisation or group of organisations.

PSTN - Public Switched Telephone Network
The public telephone system, including telephone, local and trunk lines, and exchanges.

PSU - Power Supply Unit

PTO - Public Telecommunications Operator
An organisation licensed to run a public telecommunications system.

PTT - Postal, Telegraph and Telephone Organisation
A government department responsible for and with authority over postal, telegraph and telephone operations.

PWA - Printed Wired Assembly

Q

QSIG - A PBX networking protocol produced by ECMA in line with ETSI and ITU ISDN recommendations.

R

RAID - Redundant Array of Inexpensive Disks
Several disk drives are placed into a single housing. Data is written over the disk drives in such a way that if one or more of the drives are lost, none of the data will be lost.

Remote Access - The ability to access your mailbox remotely, when you are away from your desk or out of the office.

S

SBC - Screen Based Console
The computer based Realitis DX attendant console incorporating interactive on-screen directory system.

SCSI - Small Computer System Interface

Service level - The service level is a definition of perceived customer satisfaction. Service level is usually measured as the percentage of calls answered successfully within a predefined period of ringing.

Short code dialling - The ability to make calls from a predetermined list by using a simple abbreviated instruction.

SIP - Session Initiated Protocol.

SPI - Service Providers Interface

SQL - Structured Query Language. Database language invented by IBM and used for creating, maintaining and viewing database.