This is a glossary of telephony terms, derived from the Glossary of Telecommunication Terms published as Federal Standard 1037C. Please see the Federal Standard article for copyright-related issues, as not all parts of the source document are in the public domain.

ISDN

access contention -- B channel -- bearer service -- broadband ISDN (B-ISDN) -- circuit transfer mode -- contribution -- customer access -- D channel -- demand service -- digital subscriber line (DSL) -- distribution -- distribution service -- event -- frame -- functional signaling -- H-channel -- hybrid interface structure -- interactive service -- interface functionality -- interface payload -- ISDN -- labeled channel -- labeled interface structure -- labeled multiplexing -- labeled statistical channel -- LAP-D -- messaging service -- network element (NE) -- network termination -- network termination 1 (NT1) -- network termination 2 (NT2) -- positioned channel -- post-production processing -- primary rate interface (PRI) -- reference configuration -- reference point -- reserved circuit service -- retrieval service -- R interface -- Signaling System No. 7 (SS7) -- S interface -- synchronous transfer mode -- teleaction service -- terminal adapter -- T-interface -- transfer mode -- transit delay -- T reference point -- U interface -- V reference point -- wide area network (WAN)

Switching

analog switch -- broadband exchange (BEX) -- burst switching -- call progress signal -- circuit-switched data transmission service -- circuit switching -- class of office -- common control -- congestion -- crosspoint -- digital switching -- distributed switching -- electronic switching system (ESS) -- fast packet switching -- first-in last-out (FIFO) -- interrupted continuous wave (ICW) -- joint multichannel trunking and switching system -- message switching -- multiple access -- multiple homing -- nonblocking switch -- off-hook signal -- one-way trunk -- pilot-make-busy circuit (PMB) -- private exchange (PX) -- public switched network (PSN) -- public switched NS/EP telecommunications services -- public switched telephone network (PSTN) -- queuing delay -- rotary hunting -- seizing -- semiautomatic switching system -- signal transfer point (STP) -- space-division switching -- spill forward -- split homing -- step-by-step switching system (SXS) -- switch -- switchboard -- switch busy hour -- switching -- synchronous transfer mode -- Tactical Automatic Digital Switching System (TADSS) -- thin-film optical switch -- three-way calling -- time-division switching -- trunk -- wink pulsing

Telephony Hardware

acoustic coupler -- aerial cable -- aerial insert -- applique -- central office (C.O.) -- combined distribution frame (CDF) -- common battery -- conditioned loop -- connecting arrangement -- cord circuit -- cord lamp -- cordless switchboard -- crossbar switch -- cross-connection -- cross-office trunk -- customer office terminal (COT) -- customer service unit (CSU) -- dial switching equipment -- digital access and cross-connect system (DACS) -- digital circuit patch bay -- digital loop carrier (DLC) -- digital primary patch bay -- digital switch -- distribution frame -- drop -- DSA board -- D-type patch bay -- electrically powered telephone -- embedded base equipment -- embedded customer-premises equipment -- end instrument -- end office -- entrance facility -- entrance point -- entrance room -- equal-level patch bay -- equipment room -- equipment side -- exchange -- exchange facilities -- extension bell -- four-wire repeater -- grandfathered systems -- grandfathered terminal equipment -- group distribution frame (GDF) -- high-frequency distribution frame (HFDF) -- individual line -- inside plant -- integrated station -- intercom -- intermediate distribution frame (IDF) -- interoffice trunk -- interposition trunk -- interswitch trunk -- intertoll trunk -- intraoffice trunk -- key set -- key telephone system (KTS) -- K-type patch bay -- limited-protection voice equipment -- line side -- local battery -- local exchange loop -- local side -- main distribution frame (MDF) -- main station -- master frequency generator -- MM patch bay -- new customer premises equipment -- office classification -- off-premises extension (OPX) -- on-premises extension -- orderwire multiplex -- outside plant -- patch and test facility (PTF) -- plant -- private exchange (PX) -- private line -- proration -- protected distribution system (PDS) -- public switched telephone network (PSTN) -- rack -- repertory dialer -- rotary dial -- SECORD -- semiautomatic switching system -- signal center -- sound-powered telephone -- special grade access line -- splice closure -- station battery -- STU -- supergroup distribution frame (SGDF) -- switchboard -- switched circuit -- switched loop -- tandem center -- tandem office -- technical control facility (TCF) -- Telecommunications Device for the Deaf (TDD) -- telecommunications facilities -- telephone -- terminal equipment -- through-group equipment -- through-supergroup equipment -- tie trunk -- translator -- tributary office -- videophone -- vodas -- vogad -- voice frequency primary patch bay (VF)