2-wire line - The set of two copper wires that is used to connect telephone customers with a switching office, loosely wrapped around each other to minimize interference from other twisted pairs in the same bundle. Synonymous with twisted pair.

ADSL - See Asymmetric Digital Subscriber Line.

Analog - A continuously varying signal or wave. As with all waves, analog waves are usually susceptible to interference which can change the character of the wave.

Asymmetric digital subscriber line (ADSL) - A group of DSL technologies that reserve more bandwidth in one direction than the other, which is advantageous for users that do not require equal bandwidth in both directions. See DSL.

Asynchronous transfer mode (ATM) - A method of data transportation whereby fixed length packets are sent over a switched network. The ability to ensure reliable delivery of packets at a high rate makes it suitable for carrying voice, video, and data.

Bandwidth - A measure of capacity of communications media. Greater bandwidth allows communication of more information in a given period of time. Bandwidth is generally described either in terms of analog signals in units of Hertz (Hz), which describes the maximum number of cycles per second, or in terms of digital signals in units of bits per second.

Broadband - An adjective used to describe large-capacity networks that are able to carry several services at the same time, such as data, voice, and video.

Byte - A compilation of bits, seven bits in accordance with ASCII standards and eight bits in accordance with EBCDIC standards.

Central office (CO) - A telephone company facility that handles the switching of telephone calls on the public switched telephone network (PSTN) for a small regional area.

Circuit-switched network - A type of network in which a continuous link is established between a source and a receiver. Circuit switching is used for voice and video to ensure that individual parts of a signal are received in the correct order by the destination site.

CO - See central office

Collocation -An arrangement whereby the facilities of one party (the Collocating Party) are terminated with the equipment necessary to provide interconnection or access to the network elements offered by the second Party

Competitive local exchange carrier (CLEC) - An American term for a telephone company that was created after the Telecommunications Act of 1996 made it legal for companies to compete with the ILECs. Contrast with ILEC.

CLEC - See competitive local exchange carrier.

Compression - The process of reducing the amount of information necessary to transmit a specific audio, video, or data signal. core network - The combination of telephone switching offices and transmission plant connecting switching offices together. In the U.S. local exchange network, core networks are linked by several competing Interexchange networks; in the rest of the world the core network extends to national boundaries.

Customer premises equipment (CPE) - Any piece of equipment in a communication system that resides within the home or office. Examples include modems, television set-top boxes, telephones and televisions.

Dedicated Line A communications circuit or channel provided for the exclusive use of a particular subscriber. Dedicated lines are used for computers when large amounts of data need to be moved between points

Dial-up connection - A data communication link that is established when the communication equipment dials a phone number and negotiates a connection with the equipment on the other end of the link.

Digital signal - A signal that takes on only two values, off or on, typically represented by "0" or "1." Digital signals require less power but (typically) more bandwidth than analog, and copies of digital signals can be made exactly like the original.

Digital subscriber line (DSL) - A data communications technology that transmits information over the copper wires that make up the local loop of the public switched telephone network (See local loop).) It bypasses the circuit-switched lines that make up that network and yields much faster data transmission rates than analog modem technologies

Digital Signal 3 (DS3) A Special Access Service comparable to having 672 voice-grade channels capable of handling multiple data streams in high volume at speeds up to 44.736 Mbps (commonly referred to as a 45 Megabit channel).

E-1 - A dedicated digital communication link provided by a European telephone company that offers 2.048 megabits per second of bandwidth, commonly used for carrying traffic to and from private business networks and Internet service providers

Echo cancellation - The elimination of reflected signals ("echoes") in a two-way transmission created by some types of telephone equipment, used in data transmission to improve the bandwidth of the line.

Ethernet -A 100-Mbps technology based on the 10Base-T Ethernet CSMA/CD network access method to accommodate the operation of local area networks (LANs).

Fast Ethernet A 100-Mbps technology based on the 10Base-T Ethernet CSMA/CD Network access method for operating local area networks (LANs).

Frame relay - A high-speed packet switching protocol used in wide area networks (WANs), often to connect local area networks (LANs) to each other, with a maximum bandwidth of 44.725 megabits per second.

Gigabyte - 1,000,000,000 bytes, or 1,000 megabytes (see Byte).

Hypertext markup language (HTML) - The computer language used to create hypertext documents, allowing connections from one document or Internet page to numerous others. HTML is the primary language used to create pages on the World Wide Web.

Hypertext transfer protocol (HTTP) - The first part of an address (URL) of a site on the Internet, signifying a document written in Hypertext Markup Language (HTML).

IDSL - See ISDN digital subscriber line.

ILEC - See incumbent local exchange carrier.

Incumbent local exchange carrier (ILEC) - A large telephone company that has been providing local telephone service in the United States since the divestiture of the AT&T telephone monopoly in 1982.

Integrated services digital network (ISDN) - A circuit-switched communication network, closely associated with the public switched telephone network, which allows dial-up digital communication at speeds up to 128 kilobits per second.

Inter-exchange carrier (IXC) - A long-distance telephone carrier.

Internet protocol (IP) - The standard signaling method used for all communication over the Internet

Internet service provider (ISP) - An organization offering and providing Internet access to the public using computer servers connected directly to the Internet.

Intranet - A network serving a single organization or site that is modeled after the Internet, allowing users access to almost any information available on the network. Unlike the Internet, intranets are typically limited to one organization or one site, with little or no access to outside users.

JPEG - See Joint Photographic Experts Group.

Kilobit - One thousand bits (see bit).

Kilobyte - One thousand bytes (see byte).

Last mile - See local loop.

Local access transport area (LATA) - The geographical areas defining local telephone service. Any call within a LATA is handled by the local telephone company, but calls between LATAs must be handled by long-distance companies, even if the same local telephone company provides service in both LATAs.

Local area network (LAN) - A network connecting a number of computers to each other or to a central server so that the computers can share programs and files.

Local exchange carrier (LEC) - A local telephone company. LECs provide telephone service for phone calls originating and terminating within a single LATA.

Local loop - The copper lines between a customer's premises and a telephone company's central office (See central office).

Mb/s - Megabits per second.

Megabit - One million bits.

Megabyte - 1,000,000 bytes, or 1,000 kilobytes (see Byte).

Millions of instructions per second (MIPS) - This is a common measure of the speed of a computer processor.

Modem (Modulator Demodulator) - A device that converts digital data into analog signals and vice-versa for transmission over a telephone line.

MPEG-1 - An international standard for the digital compression of VHS-quality, full-motion video.

MPEG-2 - An international standard for the digital compression of broadcast-quality, full-motion video.

MPEG-3 - An international standard for the digital compression of broadcast-quality, audio.

Multicast - The transmission of information over the Internet to two or more users at the same time.

Multiplexing - Transmitting multiple signals over a single communications line or computer channel. The two common multiplexing techniques are frequency division multiplexing, which separates signals by modulating the data onto different carrier frequencies, and time division multiplexing, which separates signals by interleaving bits one after the other.

NAP - See network access provider.

Narrowband - A designation of bandwidth less than 56 kilobits per second.

Network access provider (NAP) - Another name for a provider of networked telephone and associated services, usually in the U.S.

Network service provider (NSP) - A high-level Internet provider that offers high-speed backbone services.

Network termination equipment (NTE) - The equipment at the ends of the communication path.

N-ISDN - See narrowband ISDN.

NSP - See network service provider.

NTE - See network termination equipment.

Optical carrier 3 (OC-3) - A fiber optic line carrying 155 megabits per second; a U.S. designation generally recognized throughout the telecommunications community worldwide.

Packet-switched network - A network that allows a message to be broken into small "packets" of data that are sent separately by a source to the destination. The packets may travel different paths and arrive at different times, with the destination sites reassembling them into the original message. Packet switching is used in most computer networks because it allows a very large amount of information to be transmitted through a limited bandwidth.

Plain old telephone service (POTS) - An acronym identifying the traditional function of a telephone network to allow voice communication between two people across a distance. In most contexts, POTS is synonymous with the public switched telephone network (PSTN).

Point of presence (POP) - The physical point of connection between a data network and a telephone network.

Postal, Telegraph and Telephone (PTT) - The generic European name usually used to refer to state-owned telephone companies.

POTS - See plain old telephone service.

PRI-ISDN - See primary-rate ISDN.

Primary-rate ISDN (PRI-ISDN) - The primary rate ISDN interface provides 23 64 Kb/s channels (called B channels) to carry voice or data and one 16 Kb/s signaling channel (the D channel) for call information.

Private Line A communications service between specific locations that involves dedicated circuits, private switching arrangements, and/or predefined transmission paths, whether virtual or physical.

PTT - See Postal, Telegraph and Telephone. public switched telephone network (PSTN) - The worldwide communications network that carries phone calls and data.

No terms available.

RBOC - See Regional Bell Operating Company.

Regional Bell Operating Company (RBOC) - One of the seven local telephone companies formed upon the divestiture of AT&T in 1984. The seven are: NYNEX, Bell Atlantic, BellSouth, Southwestern Bell, U S WEST, Ameritech, and Pacific Telesis.

Router - The central switching device in a packet-switched computer network that directs and controls the flow of data through the network.

Sdsl - Symmetric Digital Subscriber Line - This technology provides the same bandwidth in both directions, upstream and downstream. That means whether you're uploading or downloading information, you have the same high-quality performance. SDSL provides transmission speeds within a T1/E1 range, of up to 1.5 Mbps at a maximum range of 12,000 - 18,000 feet from a central office, over a single-pair copper wire. This option is ideal for small and medium sized businesses that have an equal need to download and upload data over the Internet.

T-1 - Also known as DS1 and T1, a T-1 is dedicated digital communication link provided by a telephone company that offers 1.544 megabits per second of bandwidth, commonly used for carrying traffic to and from private business networks and Internet service providers.

T-3 - Also known as DS3 and T3, a T-3 is a dedicated digital communication link provided by a telephone company that offers 44.75 megabits per second of bandwidth, commonly used for carrying traffic to and from private business networks and Internet service providers.

Terabyte - 1,000,000,000,000 bytes, or 1,000 gigabytes (see Byte).

time division multiplexing (TDM) - A digital data transmission method that takes signals from multiple sources, divides them into pieces which are then placed periodically into time slots, transmits them down a single path and reassembles the time slots back into multiple signals on the remote end of the transmission.

Transmission control protocol/Internet protocol (TCP/IP) - A method of packet-switched data transmission used on the Internet. The protocol specifies the manner in which a signal is divided into parts, as well as the manner in which "address" information is added to each packet to ensure that it reaches its destination and can be reassembled into the original message.

Twisted pair - The set of two copper wires used to connect a telephone customer with a switching office, loosely wrapped around each other to minimize interference from other twisted pairs in the same bundle. Synonymous with 2-wire line.

UAWG - See Universal ADSL Working Group.

Universal Serial Bus (USB) - A computer interface with a maximum bandwidth of 1.5 Megabytes per second used for connecting computer peripherals such as printers, keyboards and scanners.

Universal service provider (USP) - A company that sells access to phone, data, and entertainment services and networks.

Variable bit rate (VBR) - A data transmission that can be represented by an irregular grouping of bits or cell payloads followed by unused bits or cell payloads.

VDSL - See very high bit rate digital subscriber line. very high bit rate digital subscriber line (VDSL) - An asymmetric DSL that delivers from 13 to 52 megabits per second downstream bandwidth and 1.5 to 2.3 megabits per second upstream.

video on demand (VOD) - A pay-per-view television service in which a viewer can order a program from a menu and have it delivered instantly to the television set, typically with the ability to pause, rewind, etc.

Video conference - Interactive, audiovisual communication among three or more people at two or more sites.

WAN - See wide area network.

Wide area network (WAN) - A network that interconnects geographically-distributed computers or LANs.

No terms available.

No terms available.

No terms available.