-
Wide-Area Network (WAN)
A data communications network that serves users across a broad geographic area and often uses transmission devices provided by common carriers.
-
Enterprise Network
A large and diverse network connecting most major points in a company or other organization. Differs from a WAN in that it is privately owned and operated.
-
Data Communications
The sending and receiving of data between two endpoints.
-
Transaction
A result-oriented unit of communication processing.
-
Voice over IP (VoIP)
The capability to carry normal telephony-style voice over an IP-based internet with POTS-like functionality.
-
Broadband
A transmission system that multiplexes multiple independent signals onto the cable.
-
Teleworker
An employee who enjoys some flexibility in working location and hours. The daily commute to an office is replaced by telecommunication links.
-
Wiring Closets
A specially designed room used to wire a data or voice network.
-
Backbone
The part of a network that acts as the primary path for traffic that is most often sourced from and destination for other networks.
-
Metropolitan-area Network (MAN)
A network that spans a metropolitan area.
-
Frame Relay
An industry-standard switched data link layer protocol that handles multiple virtual circuits using HDLC encapsulation between connected devices.
-
Asynchronous Transfer Mode (ATM)
An international standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in the fixed-length (53-byte) cells.
-
High-Level Data Link Control (HDLC)
A bit-oriented synchronous data link layer protocol developed by ISO.
-
Customer Premises Equipment (CPE)
Terminating equipment, such as terminals, telephones, and modems, supplied by the telephone company, installed at customer sites, and connected to the telephone company network.
-
Channel
- A communication path.
- In IBM, the specific path between large computers (such as mainframes) and attached peripheral devices.
-
Data Communications Equipment (DCE)
The devices and connections of a communications network that comprise the network end of the user-to-network interface.
-
Data Terminal Equipment (DTE)
A device at the user end of a user-network interface that serves as a data source, destination, or both.
-
Local Loop
A line from the premise of a telephone subscriber to the telephone company CO.
-
Cable
A transmission medium of copper wire or optical fiber wrapped in a protective cover.
-
Demarcation Line
A communications line that is indefinitely reserved for transmissions, rather than switched as transmission in required.
-
Central Office (CO)
A local telephone company office to which all local loops in a given area connect and in which circuit switching of subscriber lines occurs.
-
-
Modem
A device that converts digital and analog signals.
-
T1
- A digital WAN carrier facility.
- Transmits DS1 formatted data at 1.544 Mbps through the telephone switching network, using AMI or B8ZS coding.
-
T3
- A digital WAN carrier facility.
- Transmits DS3 formatted data at 44.736 Mbps through the telephone switching network
-
Channel Service Unit (CSU)
A digital interface device that connects end-user equipment to the local digital telephone loop.
-
Data Service Unit (DSU)
A device used in digital transmission that adapts the physical interface on a DTE device to a transmission facility such as T! or E1.
-
T-carrier
A TDM transmission method that usually refers to a line or cable carrying a DS-1 signal.
-
Access Server
A communications processor that connects asynchronous device to a LAN or WAN through network and terminal emulation software.
-
X.25
An ITU-T standard that defines how connections between DTE and DCE are maintained for remote terminal access and computer communications in packet data networks (PDN).
-
Public Switched Telephone Network (PSTN)
- A general term referring to the variety of telephone networks and services in place worldwide.
- Plain old telephone service (POTS)
-
Integrated Services Digital Network (ISDN)
A communication protocol, offered by telephone companies, that permits telephone networks to carry data, voice, and other source traffic.
-
Point of Presence (POP)
A point of interconnection between the communications facilities provided by the telephone company and the building's main distribution facility.
-
Core Router
In a packet-switched star topology, a router that is part of the backbone and that serves as the single pipe through which all traffic from peripheral networks must pass on its way to other peripheral networks.
-
High-Speed Serial Interface (HSSI)
A network standard for high-speed (up to 52 Mbps) serial connections over WAN links.
-
Point-to-point Protocol (PPP)
- A successor to SLIP.
- Provides router-to-router and host-to-network connections over synchronous and asynchronous circuits.
-
Circuit
A communications path between two or more points.
-
Time-Division Multiplexing (TDM)
A technique in which information from multiple channels can be allocated bandwidth on a single wire based on preassigned time slots.
-
Circuit-Switching
A switching system in which a dedicated physical circuit path must exist between sending and receiver for the duration of the "call."
-
Packet Switching
A networking method in which modes share bandwidth with each other by sending packets.
-
Packet-Switched Network
Uses packet-switching technology to transfer data.
-
Connectionless
A term used to describe data transfer without the existence of a virtual circuit.
-
Connection-Oriented
A term used to describe data transfer that requires that establishment of a virtual circuit.
-
Data Link Connection Identifiers (DLCI)
A value that specifies a PVC or SVC in a Frame Relay network.
-
Virtual Circuit (VC)
A logical circuit created to ensure reliable communication between two network devices.
-
Permanent Virtual Circuits (PVC)
A virtual circuit that is permanently established.
-
Switched Virtual Circuits (SVC)
A virtual circuit that is dynamically established on demand and that is torn down when transmission in complete.
-
Leased Line
A transmission line reserved by a communications carrier for a customer's private use.
-
Telephony
The science of converting sound to electrical signals and transmitting it between widely removed points.
-
Bearer (B) Channels
In ISDN, a full-duplex 64-kbps channel used to send user data.
-
Signaling
The process of sending a transmission signal over a physical medium or purposes of communication.
-
Delta (D) Channel
A full-duplex 16-Kbps (BRI) or 64-kbps (PRI) ISDN channel.
-
Basic Rate Interface (BRI)
An ISDN interface composed of two B channels and one D channel for circuit-switched communication of voice, video, and data.
-
Primary Rate Interface (PRI)
An ISDN interface to primary rate access.
-
Synchronization
The establishment of common timing between sender and receiver.
-
E1
A wide-area digital transmission scheme used predominantly in Europe tat carries data at a rate of 2.048 Mbps.
-
J1
A wide-area digital transmission scheme used predominantly in Japan that carries data at a rate of 1.544 Mbps.
-
Call Setup Time
A time required to establish a switched call between DTE devices.
-
-
Coaxial Cable
A cable consisting of a hollow cylindrical conductor that surrounds a single inner wire conductor.
-
Cable Television
A communication system in which multiple channels of programming are transmitted to homes using broadband coaxial cable.
-
Headend
The endpoint of a broadband network.
-
Microwave
Electromagnetic waves in the range 1 to 30 GHz.
-
Firewall
A router or access server designated as a buffer between any connected public network and a private network.
-
Wiring Closet
Serve as a central junction point for the wiring and wiring equipment that is used to interconnect network devices.
-
Metropolitan-area Network (MAN)
A network that generally spans a larger geographic area than a LAN but a smaller geographic area than a WAN.
|
|