A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

Active Ethernet
An Ethernet standards compliant access architecture solution which utilizes switches/routers deployed into the access / distribution plant. An Active Ethernet architecture is sometimes referred to as a dedicated star. An Active Ethernet solution is characterized by the highest level of bandwidth delivered, highest level of interoperability, and lowest cost.

Access Charge
A fee charged for the use of a network.

American National Standards Institute (ANSI)
A national voluntary organization that develops and publishes standards for data communications, programming languages, magnetic storage media, the OSI model, office systems, and encryption.

Analog
A signal transmitted as a pattern of continually changing electromagnetic waves is referred to as an analog signal.

APON
An Asynchronous Transfer Mode (ATM) based Passive Optical Network (PON).

Asymmetric Digital Subscriber Line (ADSL)
Technology used to deliver high-speed digital communications across the local loop.

Asymmetric Digital Subscriber Line (ADSL) Lite
ADSL Lite is a slightly slower version of ADSL.

Asynchronous Transfer Mode (ATM)
A connection-oriented service that segments data into a succession of small units called cells. Data transmitted from multiple sources is segmented into cells by the ATM network device, and the cells are then interleaved onto a single transmission media. It is asynchronous in the sense that the recurrence of cells depends upon the required or instantaneous bit rate.

B

Broadband
A method of communication where the signal is transmitted by being impressed on a high-frequency carrier offering integrated access to voice, high-speed data service, video-demand services, and interactive delivery services. Historically, the minimum rate of transmission required to be considered Broadband is 45Mbps; the FCC has created a definition of Broadband which is 200Kbps. The FCC’s definition is sometimes modified to be called ‘little’ broadband to better differentiate it from true Broadband.

BPON
Broadband Passive Optical Network (PON) are typically a PON network operating at a shared speed of 1Gbps

Backbone
A backbone is the portion of a network that carries the most significant traffic. It is also the part of the network that connects many smaller networks to form a larger network.

Bandwidth
The total information-carrying capacity of a network or transmission line to carry signals. The necessary bandwidth is the amount of spectrum required to transmit the signal without distortion or loss of information. In an analog network, it is the difference between the highest and lowest frequencies that can be transmitted across a transmission line. Bandwidth is measured in Hz for analog networks and bps for digital networks. See hertz (Hz) and bits per second (bps).

Bits per second (bps)
The number of binary bits transmitted per second is measured in bps.

C

Carrier
A company which provides communications circuits  

Central office (CO)
Telephone company facility where subscribers' lines are joined to switching equipment for connecting subscribers to local and long distance services.

Coaxial cable
A type of copper wiring typically used for cable television transmission. Coaxial cable typically consists of a central copper or copper-coated conductor surrounded by flexible insulation, a shield of wire mesh, and an outer plastic jacket.

Co-location
A physical and business arrangement to connect the network of a CLEC (pronounced "see-lek") to that of the ILEC (pronounced "eye-lek"). To do this, a CLEC usually installs interconnection equipment at the ILEC's central switching office.

Common carrier
Licensed, private utility company that supplies communication services to the public at regulated prices

Community Antennae Television (CATV)
A service through which subscribers pay to have local television stations and additional programs brought into their homes from an antenna via a coaxial cable.

Competitive access provider (CAP)
A company that provides fiber optic links to connect urban business customers to IXCs, bypassing the LEC. Once these fiber optic links are in place in major metropolitan areas, CAPs can begin to expand their service offerings.

Competitive local exchange carrier (CLEC)
Telecommunications resellers, or brokers, who sell data services, Internet access, and local toll calling to businesses and residential customers.

Copper pair
Two copper wires that carry voice or data signals to a customer are referred to as a copper pair. See local loop.

D

Dark Fiber
Refers to unused fiber-optic cable.

Digital Video Recorder (DVR)
Device capable of accepting one or more video and audio input signals for recording onto digital storage media. Sometimes referred to as Personal Video Recorders or PVR.

Digital
Refers to a signal transmitted as a pattern of binary bits. Information is represented as a series of 1s and 0s, high or low electrical voltages, or the absence or presence of light.

Digital Cross-Connect System (DCS)
See Digital Access Cross-Connect System (DACS).

Digital Subscriber Line (DSL)
A modem technology that converts existing twisted pair telephone lines into data lines that can also carry separate telephone communications.

Digital Television (DTV)
Technology for and receiving broadcast television signals.

Divestiture
The breakup of AT&T and the Bell System by the U.S. Justice Department in 1984 to end an illegal monopoly, AT&T was ordered to separate itself from its 22 local Bell operating companies, which were reorganized into seven RBOCs. AT&T was then restricted to long-distance business, while the RBOCs were limited to local (intraLATA) service.

Downstream
Data transmitted from a CO to the customer premises is referred to as downstream data.

E

EPON
Ethernet based Passive Optical Network (PON). Another term sometimes used to refer to a BPON. Although an EPON is not compliant with standard Ethernet, the solution is closely aligned with the Ethernet standard.

Extranet
An extranet is a TCP/IP network that provides both private intranet services and limited public Internet services.

F

Facility
The physical equipment, or medium, necessary to provide a telecommunications service. For example, twisted pairs of copper wire, or fiber optic cables, are facilities.

Fiber-in-the-loop (FITL)
FITL is a broadband communications service carried from the CO to the subscriber's premise over SONET. The SONET ring terminates at the curb, and signals radiate from an optical networking unit (hub) in a star pattern over copper cabling.

Fiber optic cable
The fastest and most advanced medium for transmitting. Operates at the highest speed and high capacity communication technology in which light is used to transport information from one point to another. It consists of a flexible clear glass or plastic core surrounded by a reflective plastic cladding layer and protected by a thin jacket or sheath. A signal is transmitted by focusing a light source into the core. By using fiber optic transmission, digital signals can travel for long distances with a high degree of accuracy.

FTTB
Fiber-to-the-Business

FTTC
Fiber-to-the-Curb/Cabinet. A FTTC access solution utilizes either a metallic, copper of coax, cable or a wireless access infrastrcuture to reach the end-user.

FTTH
Fiber-to-the-Home

FTTP
Fiber-to-the-Premise

FTTX
Fiber to the 'X' where x= (P)remise (H)ome, (C)urb, (B)usiness or other locale

File Transfer Protocol (FTP)
FTP is a TCP/IP Application Layer protocol used to transfer files between two computers.

Frequency
Frequency is the number of times per second a wave swings back and forth in a cycle from its beginning point to its ending point. It is the number of wave crests, or cycles, that passes a fixed point during a particular period of time.

H

Headend
Video signals are received, digitally encoded or processed, encrypted, IP encapsulated and then transmitted from a headend facility. If the headend facility serves an analog transport network then it will typically not possess the ability to IP encapsulate the signal.

Hertz (Hz)
Analog signals are measured in cycles per second, or Hz. One cycle per second is 1 Hz; 1,000 cycles per second is 1 kHz; and 1 million cycles per second is 1 MHz.

High-Level Data Link Control (HDLC)
Data Link Layer transmission protocol used for data communications. The HDLC protocol embeds information in a data frame that allows devices to control data flow and correct errors.

High Definition Television (HDTV)
An improved television system which provides approximately twice the vertical and horizontal resolution of existing television standards. It also provides enhanced audio quality.

Hybrid fiber-Coax
A network design method, common in the cable television industry, that combines optical fiber and coaxial cable into a single network. Fiber optic cables run from a central site to neighborhood hubs. From those hubs, coaxial cable serves individual homes.

I

Incumbent local exchange carrier (ILEC)
An ILEC is the same as a LEC or RBOC.

Integrated Services Digital Network (ISDN)
A digital multiplexing technology that can transmit voice, data, and other forms of communication simultaneously over a single local loop

International Telecommunication Union- Telecommunications Standardization Sector (ITU-T)
An intergovernmental organization that develops and adopts international telecommunications standards and treaties. ITU was founded in 1865 and became a United Nations agency in 1947.

Internet
The term Internet, capitalized, refers to the global internetwork of TCP/IP networks.

internet
When written without capitalization, the term internet describes any set of two or more interconnected networks running TCP/IP protocols.

Internet service provider (ISP)
Companies that provide Internet access to individuals and businesses. ISPs typically provide a range of services necessary to provide corporate networks and other users with dedicated or dial-up access to the Internet.

Interoperable
Systems that can work together because they adhere to common technology standards that define the way devices connect and programs exchange information.

Intranet
A private network running TCP/IP protocols and applications.

L

Line
A transmission path carried over a physical local loop, usually between a switching system and a telephone.

Local access and transport area (LATA)
Geographic calling areas within which an RBOC may provide local and long distance services. LATA boundaries, for the most part, fall within states and do not cross state lines.

Local exchange
A geographical region and group of subscribers served by a single CO is referred to as a local exchange.

Local exchange carrier (LEC)
The terms LEC, ILEC, and RBOC are equivalent.

Local loop
The Pair of copper wires that connects a customer's telephone to the LEC's CO switching system. The physical facilities that connect the subscriber's premises to the CO may include twisted copper pairs, fiber optics, coaxial cable, electronic equipment, or even radio waves.

Local Number Portability (LNP)
A service mandated by the Telecommunications Act of 1996. It allows a subscriber to change service providers while maintaining the same telephone number. LNP assigns each phone number a network address, and network devices work together to quickly locate the destination, regardless of the carrier on which the address resides.

M

Message Relay Service (MRS)
Enables the deaf, hard of hearing, or persons experiencing difficulty with speech to have telephone conversations with hearing individuals using a TTY or TDD. Relay service operators relay voice conversations to and from teletype format on behalf of the call parties. No record of the conversation is kept.

Modem
The term modem is a contraction for modulator/demodulator. Modems are used to convert binary data into analog signals suitable for transmission across a telephone network.

Multiplexer (MUX)
The term MUX refers to electronic equipment that allows multiple signals to travel over a single channel. Multiple signals are fed into a MUX and combined to form one output stream.

N

Network
An interconnection of computer systems, terminals or data communications facilities.

Network access point (NAP)
One of several common U.S. Internet backbone connecting points designed to serve the general public.

Network Operating Center (NOC)
Location from which the operation of a network or internet is monitored. Additionally, this center usually serves as a clearinghouse for connectivity problems and efforts to resolve those problems.

Node
A node is any device connected to a network. Typically, nodes are thought of as workstations or PCs that have communication capabilities.

Number Portability
A service mandated by the Telecommunications Act of 1996. It allows a subscriber to change service providers while maintaining the same telephone number. LNP assigns each phone number a network address, and network devices work together to quickly locate the destination, regardless of the carrier on which the address resides.

O

Open Service Provider Network (OSPN)
An advanced telecommunications network where the ownership of the network is separate from those providing retail services. Retail service providers pay a wholesale price to the network owner. A true OSPN is based on four principles (1) open and wholesale, (2) carrier-class, (3) high-scalable bandwidth, and (4) an open and independent architecture.

Optical carrier (OC)
OC identifies the various sizes of optical transmission services provided by SONET technology.

P

Personal Video Recorder (PVR)
Similar to a VCR but instead of using video tape, uses a built-in hard drive to digitally record programs and offers the ability to pause live television.

Passive Optical Network (PON)
An Optical Line Termination (OLT) at the communication company's office and a number of Optical Network Units (ONUs) near end users. Typically a number (32) of ONUs or end users are connected to an OLT utilizing the same fiber. The passive describes the fact that all of the optical termination equipment is located on average more than 5 km from the end-user.

Packet
A unit of digital information that can be transmitted over a network is referred to as a packet. Information contained in a packet is sufficient to transmit the packet from the sending node to the receiving node, even when the packet must traverse intermediate nodes. A packet can be an entire message, or a segment of a much larger message.

Plain old telephone service (POTS)
The term commonly used to describe the basic, single-line analog telephone service used to connect to the PSTN. POTS provides no added features, such as Caller ID or call waiting, just plain old analog telephone service.

Point of presence (POP)
The physical transfer point between two net­works. In most cases, the POP is a CO switch located in the same building as the LEC CO.

Point-to-Point Protocol (PPP)
An Internet standard communication protocol that offers support for multiple network protocols, data compression, host configuration, and link setup. PPP is based on the HDLC standard.

Private branch exchange (PBX)
A sophisticated business telephone system that provides all the switching features of a CO switch.

Protocol
A defined method of communication between computers or computer applications.

Provisioning
Provisioning is the process of allocating transmission lines, switching capacity, and central programming to provide telecommunications service to a customer.

Public-Switched Telephone Network (PSTN)
PSTN is the worldwide voice telephone network accessible to anyone with a telephone. The PSTN typically refers to the network which is currently using the existing copper plant and circuit based switches.

Q

Quality of service (QoS)
QoS defines a type of service a communications link can provide. QoS often specifies factors such as delay, throughput, and error rate.

Queue
A waiting line for telephony service is referred to as a queue. For example, if all agents in a call center are busy, incoming calls are placed on hold in a queue, so that the calls will be answered in the order they were received.

R

Radio frequency interference (RFI)
RFI is the disruption of a signal caused by a source that generates a wave at the same frequency and along the same path as that signal with which it interfered.

Regional Bell Operating Company (RBOC)
An RBOC is one of seven companies formed from AT&T's 22 local telephone companies during the breakup of the Bell System. The terms RBOC, LEC, and ILEC are equivalent.

Ring
Describes the deployment of fiber in a physically redundant fashion such that traffic can flow in either of two directions reducing the risk or duration of an outage. Ring also refers to one wire of an analog local loop. The term is a holdover from the days of manual switching, when one wire of a twisted pair was connected to a ring on the operator's switchboard plug. The other wire is called the "tip."

S

Service Provider
A provider of one or more communications services on a network.

Slamming
The term used to describe what occurs when a customer’s long distance service is switched from one long distance company to another without the customer’s permission. Such unauthorized switching violates FCC rules.

Spectrum
The range of electromagnetic radio frequencies used in the transmission of voice, video (television) and data.

Serial Line Interface Protocol (SLIP)
A simple communications protocol originally developed for use over dedicated circuits or leased lines; it does not include provisions for establishing a connection over the telephone network.

Signaling System 7 (SS7)
SS7 is an out-of-band system that exchanges con­trol signals and call routing information between CO switches. SS7 is a separate network that connects all COs, regardless of where they are or to whom they belong.

Synchronous Optical Network (SONET)
A broadband networking standard based on point-to-point optical fiber networks. SONET will provide a high-bandwidth "pipe" to support ATM-based services.

T

Tariff
The documents filed by a carrier describing their services and the payments to be charged for such services.

Telecommunications Relay Services (TRS)
A free service that enables persons with TTYs, individuals who use sign language and people who have speech disabilities to use telephone services by having a third party transmit and translate the call.

Telephony
The word used to describe the science of transmitting voice over a telecommunications network.

TTY
A type of machine that allows people with hearing or speech disabilities to communicate over the phone using a keyboard and a viewing screen. It is sometimes called a TDD.

T1, T3
T1 and T3 are two services of the Digital Signal hierarchy for multiplexing digitized voice signals. The T-carrier family of systems includes T1, T1C, T1D, T2, T3, and T4 (and their European counterparts E1, E2, and so forth). T1 was designed such that each of 24 channels carries a digitized representation of an analog signal that has a bandwidth of 4,000 Hz. It turns out that 64 Kbps is required to digitize a 4,000-Hz voice signal. A T1 line is referred to as narrowban d and offers bandwidth of 1.544 Mbps, and a T3 is referred to as broadband and offers 44.736 Mbps.

Tandem office
A Class 5 CO that connects multiple Class 5 COs to one another and to IXC switches is referred to as a tandem office. Tandem offices do not have direct connections to end users.

Telecommunications Relay Service (TRS)
A service available to the hearing impaired.

Telnet
A TCP/IP Application Layer protocol that provides remote login capability to another computer on a network.

Terminal adapter (TA)
Sometimes refers to the voice gateway for voice over IP telephony services. The voice TA will convert the IP data for voice traffic into a standard RJ-11 analog based voice jack which will terminate any standard telephone set. Historically a TA can also refer to a hardware interface between a non-ISDN TE2 and an ISDN network.

Transformer
A transformer is an electrical device used to convert voltages from one level to another. Two types of transformers are used: step-up and step-down. A step-up transformer steps an input voltage up to a higher output voltage. A step-down transformer does just the opposite. Transformers use coils on the input and output and induce, rather than directly connect, the input onto the output. The ratio of the input to output coil turns determines the stepped-up or stepped-down voltage outputs.

Transmission Control Protocol/Internet Protocol (TCP/IP)
TCP is used to send messages reliably across a network. It is usually paired with IP, which sends data packets from one point in a network to the next. TCP/IP also describes suites of protocols, software, and applications designed to work over networks based on TCP and IP.

Twisted pair
A twisted pair is a type of copper wiring typically used for telephone and computer network transmission. A twisted pair consists of two thin copper wires, twisted around each other to cancel EMI and RFI.

U

Unbundling
The access provided by local exchange carriers so that other service providers can buy or lease portions of its network elements, such as interconnection loops, to serve subscribers.

Universal Service
The financial mechanism which helps compensate telephone companies or other communications entities for providing access to telecommunications services at reasonable and affordable rates throughout the country, including rural, insular and high costs areas, and to public institutions. Companies, not consumers, are required by law to contribute to this fund. The law does not prohibit companies from passing this charge on to customers.

Unbundled service
Communications channel leased to a CLEC by the ILEC. "Unbundled" means that the ILEC provides only the transmission service, while the CLEC provides management, provisioning, repairing, and billing.

V

Video on Demand (VOD)
A technology that makes it possible consumers to control the start of a viewed program. For example, by remote control a consumer might pick from an on-screen list of movies and start and pause it at their convenience. If fully deployed, it would eliminate the role of video rental stores and change the nature of television services.

virtual office
The business practice of forming workgroups by connecting multiple home-office workers via remote network access and e-mail is referred to as a virtual office.

Voice over Internet Protocol (VoIP)
Technology providing voice telephony services over an IP connection (like the internet.)