Glossary of Networking & Telecommunications Terms
ADSL - Asymmetric Digital Subscriber Loop. A digital subscriber loop (DSL) technology designed to allow incumbent carriers to leverage existing CAT-3 cabling plant to deliver high speed digital services. Designed for residential deployment, and relies upon asymmetry (high speed in one direction only) to delivery necessary bandwidth to consumer.
BDU - Broadcast Distribution Undertaking. CRTC regulatory classification for a facilities-based organization licensed to distribute broadcast audio and/or video services in selected Canadian markets.
BMO - Building Management Organization. Entity responsible for managing shared facilities and services delivered in commercial MTU and/or residential MDU buildings.
BRI - Basic Rate Interface. ISDN terminology for 2B+1D channels delivered over a single DS-0 or equivalent digital subscriber line.
CAT-3 - Category 3. EIA/TIA UTP cabling standard for transmission speeds up to 16 MHz; functionally equivalent to UL Level 3. Suitable for 10Base-T Ethernet, 4-Mbps Token Ring, ARCnet.
CAT-4 - Category 4. EIA/TIA UTP cabling standard for transmission speeds up to 20 MHz; functionally equivalent to UL Level 4. Suitable for 10Base-TX Ethernet, 16-Mbps Token Ring, high noise / low loss applications.
CAT-5 - Category 5. EIA/TIA UTP cabling standard for transmission speeds up to 100 MHz; functionally equivalent to UL Level 5. Suitable for 100Base-TX Fast Ethernet, 100-Mbps CDDI, ATM over copper.
CATV - Cable Television. Analog broadcast television delivered over a 750 Ohm coaxial cable plant using frequency shifting and analog muxing techniques.
CCS7 - Common Channel Signalling Seven. Telephony signalling standard for out-of-band signalling between carrier switches on the PSTN.
CLEC - Competitive Local Exchange Carrier. An alternative local access provider of telephony services in a given geographical market.
CRTC - Canadian Radio-television and Telecommunications Commission. Federal regulatory body responsible for oversight of all broadcast and telecommunications undertakings in Canada.
CTI - Computer Telephony Integration. Technologies bridging the capabilities of a computer system with the facilities available on modern telephony systems.
DS-0 - Digital Signal Zero. Telephony carrier digital signalling standard for a single POTS telephone line, equivalent to 64 Kbps.
DS-1 - Digital Signal One. Telephony carrier digital signalling standard for a copper trunk line, equivalent to 1.5 Mbps digital bandwidth.
DS-3 - Digital Signal Three. Telephony carrier digital signalling standard for a copper high density trunk line, equivalent to 30 DS-1s or 45 Mbps digital bandwidth.
DSL - Digital Subscriber Loop. Digital signalling technologies allowing for the high-speed delivery of digital data via existing CAT-3 telephony cabling plants.
DSS - Digital Satellite System. Digital broadcast system designed for the distribution of DTV signals via geosynchronous or low earth orbiting satellites.
DTMF - Dial Tone Multiple Frequency. Telephony standard for frequency coded keypad dialing.
DTV - Digital Television. Broadcast television delivered digitally, usually via MPEG-2 video streams over a broadband data network. Sometimes referred to as HDTV.
EIA/TIA - Electronics Industry Association / Telecommunications Industry Association
FTTC - Fibre To The Curb. Residential cabling system employing optical and electrical muxing and frequency shifting to minimize trunk side cabling requirements in a residential outside cabling plant. Also allows for increased future growth due to extent of fibre optics laid to neighbourhoods.
FTTH - Fibre To The Home. Residential cabling system employing either optical muxing and frequency shifting or digital optical transmission to reduce cabling infrastructure requirements in a residential outside cabling plant. Also allows for virtually unlimited future growth due to extent of fibre optics laid to individual homes.
FoIP - Fax over Internet Protocol. Delivery of fascimile telephony services over a data network using standard Internet Protocols.
HDTV - High Definition Television. North American DTV standards, allows for multiple audio and video broadcast formats and a range of resolution/quality/bandwidth options.
ILEC - Incumbent Local Exchange Carrier. The de-facto local access provider of telephony services in a given geographical market.
ISDN - Integrated Services Digital Network. Fully digital telephony network based on out-of-band signalling and consisting primarily of Bearer channels (B-channels, used to carry actual user data) and Data channels (D-channels, used to carry out-of-band signalling information).
ISO - International Standards Organization. Entity responsible for drafting industry standards in a wide variety of fields, including telecommunications.
ISP - Internet Service Provider. Organization providing Internet access and related data services via dial-up and/or dedicated digital access technologies.
IVR - Interactive Voice Response. Telephony CTI application involving the use of voice menus and DTMF user responses.
IXC - Inter-Exchange Carrier. Competitive long distance telephony carrier providing transport services for telephony call between diverse geographic markets.
LAN - Local Area Network. Data communications network installed within a single organization or building. Can be used to refer to a small campus area network spanning multiple buildings with close geographic proximity.
MAN - Metropolitan Area Network. Data communications network connecting various sites within a single metropolitan geographical area.
MPEG - Motion Pictures Experts Group. Organization charged with developing enabling technology standards to promote advanced multimedia. Developers of MPEG-1 Layer 3 (MP3) audio format and MPEG-2 broadcast quality full-motion video standards.
NTSC - National Television Standards Council. Original US. Government body responsible for the design of the North American analog television standards, known as NTSC-TV.
OC-3 - Optical Carrier Three. Telephony carrier digital signalling standard for a fibre optic trunk line, equivalent to 155 Mbps digital bandwidth.
OC-12 - Optical Carrier Twelve. Telephony carrier digital signalling standard for a high density fibre optic trunk line, equivalent to 622 Mbps digital bandwidth.
OC-48 - Optical Carrier Forty-eight. Telephony carrier digital signalling standard for a very high density fibre optic trunk line, equivalent to 2.5 Gbps digital bandwidth.
PON - Passive Optical Network. ATM based optical telecommunications network which does not require any active components (i.e. optical amplifiers) in the outside plant. Commonly used in high-density FTTH systems.
POTS - Plain Old Telephone System. Refers to traditional analog voice telephony service offerings.
PRI - Primary Rate Interface. ISDN terminology for 23B+1D or 24B channels delivered over a single DS-1 or equivalent digital carrier line.
PSTN - Public Switched Telephone Network. The global telephony network consisting of ILEC, CLEC and IXC carrier switches connected by dedicated trunk facilities and participating in the global SS7/CCS7 signalling network.
SDSL - Symmetric Digital Subscriber Loop. A DSL technology designed to allow incumbent carriers to leverage existing CAT-3 cabling plant to deliver high speed digital services. Designed for commercial deployment, and provides high speed symmetrical bandwidth to customer.
SS7 - Signalling System Seven. Equivalent to CCS7.
STP - Shielded Twisted Pair. Classification of copper cabling in which the interior conductors are encased with either a metallic mesh or solid foil shielding. Within this shielding, individually paired wires are twisted together to provide improved transmission qualities and decreased sensitivity to external noise. A number of such pairs are carried within one cable jacket (usually 2 or 4 pairs)
T-1 - Telecommunication Carrier One. Equivalent to DS-1.
T-3 - Telecommunications Carrier Three. Equivalent to DS-3.
TCP/IP - Transmission Control Protocol / Internet Protocol. A range of data transmission, addressing and routing protocols developed by the Internet Engineering Task Force (IETF) and enabling the construction and operations of the global Internet.
UL - Underwriters Laboratories. Insurance industry organization dedicated to product testing and verification of conformance to published performance specifications.
UTP - Unshielded Twisted Pair. Classification of copper cabling in which the interior conductors are not encased with any shielding. Within the outer jacketing, individually paired wires are twisted together to provide improved transmission qualities and decreased sensitivity to external noise. A number of such pairs are carried within one cable jacket (usually 2 or 4 pairs)
VoD - Video on Demand. Delivery of customized video content in an interactive manner and on a per subscriber basis.
VoIP - Voice over Internet Protocol. Delivery of voice telephony services over a data network using standard Internet Protocols.
VPN - Virtual Private Network. The construction of a private point-to-point data network using carrier facilities over a public data network. Usually involves the set-up of dedicated VPN gateways and/or packet encryption systems to enable "secure tunnelling" through the public data network.
WAN - Wide Area Network. Data communications network connecting various sites that are geographically dispersed. Typically involves the use of dedicated, leased transport facilities from a carrier or the installation of a VPN solution over a public data network (i.e. the Internet).