List of telephony terminology

This is a list of telephony terminology and acronyms which relate to telephony networks.

A

 * Advanced Intelligent Network, (AIN), see also IN or Intelligent Network
 * Automatic number announcement circuit (ANAC)
 * Automated Attendant
 * ACD - Automatic Call Distribution
 * Articulation score

B

 * Blue box - a device that was used to bypass the normal long-distance call switching tones typically used to obtain free calls.

C

 * Call originator - (or calling party, caller or A-party) a person or device that initiates a telephone call by dialling a telephone number.
 * Call waiting - a system that notifies a caller of another incoming telephone call by sounding a sound in the earpiece.
 * Called party - (or callee or B-party)
 * Caller
 * Calling party
 * Conference call (multi-party call)
 * COCOT

D

 * Dial peer
 * Dial tone
 * Distribution frame
 * Dual-tone multi-frequency signaling (DTMF)

E

 * Emergency telephone number
 * End instrument
 * Engset calculation
 * Erlang unit

F

 * Fax - (contraction of facsimile) a device connected to the telephone network to enable documents to be scanned and sent to a receiving fax machine
 * Frame - A distribution frame, a set of open wiring racks where circuits are cross connected to trunks and equipment

H

 * Handoff
 * Handover
 * Help desk
 * Howler tone (see ROH tone)
 * Hunt Group

I

 * Infrastructure
 * Intelligent Network (IN)
 * Interface functionality
 * Inside plant
 * Intelligent Network Interface Device (iNID) - replaces the Network Interface Device outside a subscriber's house like when customers subscribe to AT&T's U-verse brand of services.
 * Interactive voice response (IVR)
 * ISDN User Part (ISUP)

L

 * Line
 * Local loop
 * Long-distance operator

O

 * On-premises wiring
 * Operator assistance
 * Outside plant

P

 * Patch-through access
 * Permanent signal
 * Person-to-person
 * Plain old telephone service, or "POTS"
 * Public Switched Telephone Network (PSTN)
 * Pupinization

R

 * Receiver Off-Hook tone (ROH)
 * Red telephone box
 * Red box
 * Regional Bell Operating Company (RBOC)
 * Ringer equivalency number (REN)
 * Ringing signal
 * Rural radio service

S

 * Smartphone
 * Station-to-station
 * Signalling System 7 (SS7)

T

 * Tandem signaling
 * Tandem switch
 * Transaction Capabilities Application Part (TCAP)
 * Telemarketing
 * Telephone
 * Telephone booth
 * Telephone call
 * Telephone card
 * Telephone directory
 * Telephone exchange
 * Telephone tapping
 * Teletraffic engineering
 * Time Division Multiplexing (TDM)
 * Trap and trace
 * TWX

V

 * Vertical service code
 * Voicemail
 * Voice over Internet Protocol (VoIP)

W

 * Western Union
 * Wide Area Telephone Service (WATS)
 * WATS line
 * Wireless network
 * Wireless Telephony Applications Interface (WTAI)
 * Wi-Fi

Z

 * Zenith number