Appendix C: Glossary and Acronyms

PRI

Primary Rate ISDN

PSTN Public Switched Telephone Network

A communications network which uses telephones to establish connections between two points. Also referred to as the dial network.

PTMP Point-to-Multipoint

A connection where data is broadcast between more than two endpoints.

PTP Point-to-Point

A connection restricted to two endpoints.

PTT Post, Telegraph, and Telephone

The government agencies in many countries that traditionally operated and monopolized the public postal, telegraph, and telephone services.

QoS Quality of Service

A set of quality requirements for telephone service.

RBOC Regional Bell Operating Companies

The creation of Regional Bell Operating Companies were a result of AT&T's telephone monopoly being broken up in 1983.

REN Ringer Equivalence Number

An arbitrary value which denotes the electrical load a telephone ringer has on a line.

Digium, Inc.

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