Asynchronous Transfer Mode (ATM)
A cell-switching technique using the cell relay method of transmission to provide high speed local and enterprise-wide WAN transport. ATM is asynchronous in the sense that it is not synchronized in time to establish ownership; rather, a header field is added to each data block to identify ownership.

Broadband
A data-transmission scheme in which multiple signals share the bandwidth of a medium such as fiber-optic cable. This allows the transmission of voice, data and video signals over a single medium; for example, cable television uses broadband to deliver dozens of channel signals over a single cable.

Customized User Billing Interface System (CUBIS)
A system that allows InterExchange Carriers to monitor and update subscriber service orders. This assists in maintaining an accurate end-user customer database for billing purposes.

Dial Up
A type of communication that is established by a switched-circuit connection using the telephone network.

Digital Subscriber Line (DSL)
A generic name for a group of enhanced speed digital services provided by telephone companies. DSL services run on twisted-pair wires; they carry both voice and data.

Gateway
The entrance and exit to a communications network or system; a device or set of functions that facilitate electronic access by users to remote services or systems and vice versa. In data networks, gateways are typically a network node that connects otherwise incompatible networks. Gateways are commonly used to connect computers on one network, say a token-ring network, with those on a long-distance network. A gateway may be used to interface between two incompatible electronic mail systems or for transferring files from one system to another.

Interconnect
A company or vendor selling customer premises equipment, generally PBXs and other types of office telephone systems.An interconnect company is typically an independent distributor of products from more than one manufacturer.

Integrated Services Digital Network (ISDN)
A widely available high bandwidth switched network service providing end-to-end digital connectivity over standard phone lines for simultaneous transmission of voice and data. There are two levels of service:

   1. Basic Rate Interface-ISDN (BRI-ISDN)--provides for digital transmission of two 64 kbps bearer        channels and one 16 kbps data and signaling channel (2B+D).

   2. Primary Rate Interface-ISDN (PR I-ISDN)--provides for digital transmission of twenty three (23) 64        kbps bearer channels and one (1) 64 kbps data and signaling channel (23 B+D).

Internet
An international network of networks, originally started for military purposes, that connects millions of users instantaneously through commonly-used protocols such as TCP/IP, HTTP, FTP, Gopher, etc. The widely-used World Wide Web is available through the Internet.

Internet Address (IP Address)
Also called an IP (Internet Protocol) address; a 32-bit address assigned to hosts using TCP/IP. The address is written as four octets separated with periods (dotted decimal format) that are made up of a network section, an optional subnet section and a host section.

Internet Protocol
Part of the TCP/IP family of protocols that tracks the outgoing address of nodes, routes outgoing messages and recognizes incoming messages.

IP
Interconnection Point--The physical point on the network where two parties interconnect. The IP is the demarcation point between ownership of the transmission facility and the outside network.
Internet Protocol

IP Address
Internet Protocol address; a 32-bit address assigned to hosts using TCP/IP. The address is written as four octets separated with periods (dotted decimal format) that are made up of a network section, an optional subnet section and a host section. Also known as an Internet Address.

T-1

    A digital transmission link capable of handling 1.544 Mega bits per second.

T-3

    28 T-1 lines (See T-1).

TCP/IP (Transmission Control Protocol/Internet Program)
Protocols linking dissimilar computers across networks. TCP/IP was developed by the Department of Defense