Glossary

Archie A database developed at McGill University in Montreal. Provides a list of Internet locations where users can find free software. Name derived from the word archive. the database is located on various computer systems in the United States, Canada, Europe, and Australia.

ABI (Application Binary Interface) Application interfaces that enable binary applications to function compatibly on operating system environments with minor differences, such as varying implentations of UNIX System V for Intel-based computers.

ATM (Asynchronous Transfer Mode) A CCITT standard for cell relay. Multiple types of information, such as voice, video and data, are conveyed in small, fixed-size cells. Also, a BISDN transfer mode wherein an accelerated version of asynchronous time division multiplexing (ATDM) is used to move multiple streams of information across a communication channel. ATM is both a LAN and WAN technology.

BISDN (Broadband ISDN) Communication standards being developed by the CCITT to handle high-bandwidth applications such as video. BISDN can use ATM technology over SONET-based transmission circuits to provide data rates of 155 Mbps to 622 Mbps and beyond. Other physical layers can be used (T1, T3). See BRI, ISDN and PRI.

BRI (Basic Rate Interface) The ISDN interface composed of two B channels and one D channel for circuit-switched communication of voice, data and video. See BISDN and ISDN.

CCITT (Consultative Committee for International Telegraph and Telephone) An international organization that develops communications standards such as X.25.

CDE (Common Desktop Environment) A specification under review by X/Open to establish a common graphical user interface. Part of COSE.

Cell Relay The basis of several high-speed network protocols, including the SMDS Interface Protocol and ATM. Small, fixed-size packets, or cells, contain identifiers specifying the data stream to which they belong. Fixed-length cells can be processed and switched in hardware at very high speeds.

CORBA (Common Object Request Broker Architecture) A specification jointly published by OMG and X/Open, to define a software layer responsible for accepting and fulfilling requests for objects. Version 1.1 was completed in 1991. Version 2.0 is, among other things, tackling interoperability issues.

COSE (Common Open Software Environment) A process undertaken initially by Sun Microsystems, IBM, Hewlett-Packard, USL (Novell) and SCO to develop common sets of specifications and interfaces to promote greater interoperability. COSE has generally deferred to X/Open's formal standardization process where X/Open is actively addressing issues.

DCE (Distributed Computing Environment) DCE is an application suite developed by OSF and focused upon communications, distributed file services, naming services and security. Both DCE and ONC, an alternative, are supported by COSE member companies.

DES (Data Encryption Standard) Standard cryptographic algorithm developed by the U.S. National Bureau of Standards.

DME (Distributed Management Environment) An OSF suite of services and applications for distributed system and network management.

DNS (Domain Name System) Distributed name system used primarily to locate host IP addresses based upon host names. It consists of a hierarchical sequence of names, from specific to general.

DS0 Dedicated 56 Kbps digital lines. DS0 lines are the most common private lines in use. See T1, T3.

Ethernet A baseband LAN specification invented by Xerox Corp. and developed jointly by Xerox, Intel, and Digital Equipment Corp. Ethernet networks operate at 10 Mbps using CSMA/CD to run over coaxial cable. Ethernet is similar to a series of standards produced by IEEE and referred to as IEEE 802.3.

Frame Relay A WAN protocol generally considered a replacement for X.25, providing more efficient transmission. Frame Relay is offered at speeds from 56 Kbps up to T1 speeds.

FTP (File Transfer Protocol) A high-level Internet file transfer protocol, usually implemented at the application layer.

GIF A graphic image format in common use.

GIS (Geographic Information System) A category of highly visual and graphical applications designed to present information within its geographic context, usually as an overlay to a map or satellite image. Often used for urban growth management, natural resource planning, or to determine the best location for a retail outlet.

Gopher A database in operation since 1992, developed at the University of Minnesota, whose sports teams are known as the Golden Gophers. Provides a list of locations where users can find free software on the Internet. The Gopher database is an X.400 mail-hub, supporting X.500 directory services.

HTML Hypertext Markup Language. A tagging language derived from Standard Generalized Markup Language (SGML). A language devised for the creation of Web documents that defines areas of text and hypertext links. The HTML tags ordinarily are not visible on the documents retrieved by browsers, but some browsers allow pages to be viewed and saved with HTML markups.

HTTP Hypertext Transfer Protocol. The primary protocol used to distribute information within the World-Wide Web. Most Web URLs now begin "http://(never capitalized)." The transaction defined by HTTP consists of the client establishing a connection to the server addressed by the URL, the client issuing a request to the server for a particular document, the server responding with a status code and the text of the document if available, and finally the server and the client disconnecting to complete the transaction.

IP (Internet Protocol) A Layer 3 (network layer) protocol that contains addressing information and some control information that allows packets to be routed. See TCP/IP.

IPX (Internetwork Package Exchange) Novell Layer 3 protocol similar to XNS and IP that is used in NetWare networks.

ISDN (Integrated Services Digital Network) Communication protocols used by telephone companies to permit telephone networks to carry text, voice and other types of data. ISDN typically operates at 56/64 Kbps. See BRI, BISDN, and PRI.

PCMCIA (PC Memory Card International Association) An industry standard covering the mechanical and electrical specifications needed to interface to these credit card-size hard disks, modems, network adapters and memory cards with computer systems.

PRI (Primary Rate Interface) ISDN interface to primary rate access. Primary rate access consists of a single 64 Kbps D channel plus 23 (in the case of the 1.544 Mbps) or 30 (in the case of 2.048 Mbps) B channels for voice and/or data. See BISDN, ISDN.

T1 Digital leased-line supporting 1.54 Mbps (DS-1).

T3 Digital leased-line supporting 44.7 Mbps (DS-3).

TCP/IP (Transmission Control Protocol/Internet Protocol) The two best-known Internet protocols, often erroneously thought of as one protocol. TCP corresponds to Layer 4 (the transport layer) of the OSI reference model, and provides reliable data transmission. IP corresponds to Layer 3 (the network layer) of the OSI reference model and provides connectionless datagram service. TCP/IP was developed by the U.S. Department of Defense in the 1970s to support the construction of worldwide internetworks.

v.22 An international standard for 1200 bps data transmission.

v.22 bis An international standard for 2400 bps data transmission.

v.32 An international standard for 9600 bps data transmission.

v.32 bis An international standard for 14.4 Kbps data transmission.

v.42 An international standard error-correction protocol.

v.42 bis An international standard error-correction protocol that added data compression to the V.42 standard, allowing for speeds up to 57.6 Kbps.

X.25 An established CCITT standard that defines the packet format for data transfers in a public data network. Frame relay is similar but requires less control information in each packet. Many establishments have X.25 networks in place that provide remote terminal access. These networks can be used for other types of data, including IP, DECnet and XNS.

X.400 A CCITT recommendation specifying an OSI standard for electronic mail transfer.

URL Uniform Resource Locator. The standardized address that locates an Internet document. URLs cover a variety of protocols, including World-Wide Web pages, FTP files, newsgroups, Gopher menus, and e-mail addresses.

WAIS Wide Area Information Server. Pronounced ways. Public-domain protocol used in searching for and retrieving information stored in databases or ducuments on the Internet. WAIS client programs can interface with multiple types of terminals. Distinct from the company WAIS, Inc.


Last updated 13 Dec 95