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 Cutunexpected, and usually sudden, termination of call, line or service
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 PAM - Pulse Amplitude Modulation used to convert an analog signal to digital representation of the analog signal in each channel of a "D" Type carrier system PCM - Pulse Code Modulation is a modulation scheme used to transmit digital binary data in a T1 system 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 T1 - Digital PCM (pulse code modulated signal) transmission system based on 1's and 0's and a speed of 1.544mbps Time Division Multiplexing (TDM) Toll-free_telephone_number (TFN) A telephone number that is billed for all arriving calls, but free for the calling party. Trap and trace TWX
U
USOC Universal Service Order Code
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
Acronyms
Acronym Name Notes 1ESS Number 1 Electronic Switching System (Alcatel-Lucent) US 1FR Flat rate service US 2G second-generation mobile telephone 2.5G Enhanced 2G mobile telephone 3G third-generation mobile telephone 4ESSNumber 4 Electronic Switching System (Alcatel-Lucent) 4WTS Four-wire termination set US5ESSNumber 5 Electronic Switching System (Alcatel-Lucent) ACD Automatic Call Distribution/Director ACTS Advanced Coin Telephone Service US ADSL Asymmetric Digital Subscriber Line ANI Automatic Number Identification US AMA Automatic Message Accounting US BOK Unblocking UK CCIS Common Channel Interoffice Signaling CID Caller ID CLEC Competitive Local Exchange Carrier US CLI Caller Line Identification Europe CLID Caller Line ID UK CTI Computer telephony integration COSMOS Wire records DDCO Direct Dial Central Office (Opposite of DID) US DDD Direct Distance Dialing US DDI Direct Dialing In UK DECT Digital Enhanced Cordless Telecommunications DID Direct Inward Dialing US DMS Digital Multiplex System (e.g. DMS-100) Can DNIS Dialed Number Identification System US DSL Digital subscriber line DTMF dual-tone multi-frequency FDM Frequency-division multiplexing GPRS General Packet Radio Service GSM Global system for mobile communications GST Ground Start Trunk US IDDD International Direct Distance Dialing US IDF Intermediate distribution frame US ILEC Incumbent Local Exchange Carrier US ISD International Subscriber Dialing UK and India ISDN Integrated Services Digital Network IVR Interactive Voice Response (a.k.a. VRU) KSU Key Switching/System Unit US LST Loop Start Trunk US MDF Main Distribution Frame MF Multi-frequency US PABX Private Automatic Branch eXchange Europe PBX Private Branch eXchange US PMBX Private Manual Branch eXchange UK POTS Plain Old Telephone Service PSTN Public Switched Telephone Network RCMAC Recent Change Memory Administration Center US REN ringer equivalency number SMS Short Message Service (i.e. text messages) SF Single Frequency supervision tone (2600) US SIP Session Initiation Protocol US SP Lock Unlocking UK SS7 Signaling System 7 STD Subscriber trunk dialling UK and India T-CXR T-carrier (e.g. T-1) US TAPI Telephony Application Programming Interface TFN Toll-free telephone number TR Tip and ring US TSPS Traffic Service Position System TXE Telephone eXchange Electronic UK UAX Unit Automatic eXchange UK VoIP Voice over Internet Protocol US WAP Wireless Application Protocol WATS Wide Area Telephone Service US WTAI Wireless Telephony Applications Interface