Unless otherwise indicated, definitions in this glossary are derived from the Free On-line Dictionary of Computing [FOLDOC, 1993].
Access Control List. A list of the services available on a server, each with a list of the hosts permitted to use the service.
Asymmetric Digital Subscriber Line. A form of Digital Subscriber Line (DSL) in which the bandwidth available for downstream connection is significantly larger than for upstream.
American Registry for Internet Numbers. One of a group of regional Internet registries responsible for the allocation of various Internet resources, such as IP addresses, and the formulation of consensus-based policies.
Address Resolution Protocol. A method for finding a host's Ethernet address from its Internet address. (RFC 826).
Best Common Practice. Those non-standards track RFCs which contain information on current practices and preferred approaches to solving common problems [BCP 9].
Cisco Discovery Protocol. A method used by Cisco routers and switches to perform automatic neighbour discovery [Cisco, 2001].
Classless Inter-Domain Routing. A scheme which allocates blocks of Internet addresses in a way that allows summarisation into a smaller number of routing table entries. (RFC 1519).
Committed Information Rate. A guaranteed minimum throughput rate available on a frame relay or other network service. The network may start dropping packets when the data rate exceeds the CIR, but not before.
Dynamic Host Configuration Protocol. A protocol that provides a means to dynamically allocate IP addresses to computers on a local area network. (RFC 2131).
Domain Name System. A general-purpose distributed, replicated, data query service chiefly used on Internet for translating hostnames into Internet addresses. (STD 2).
Digital Subscriber Line. A family of digital telecommunications protocols designed to allow high speed data communication over the existing copper telephone lines between end-users and telephone companies. Also known as xDSL.
Digital Subscriber Line Access Multiplexer. The generic term for the central office equipment where xDSL lines are terminated.
Document Type Definition. The definition of a document type in SGML or XML, consisting of a set of mark-up tags and their interpretation.
Global System for Mobile Communications. A standard for digital cellular communications (in the process of being) adopted by over 60 countries.
HyperText Markup Language. A hypertext document format used on the World-Wide Web. HTML is built on top of SGML.
HyperText Transfer Protocol. The client-server TCP/IP protocol used on the World-Wide Web for the exchange of HTML documents. (RFC 2068).
Internet Assigned Numbers Authority. The central registry for various "assigned numbers": Internet Protocol parameters, such as port, protocol, and enterprise numbers; and options, codes, and types. (RFC 3232).
Internet Control Message Protocol. An extension to the Internet protocol that allows for the generation of error messages, test packets, and informational messages related to IP. (RFC 792)
Institute of Electrical and Electronics Engineers. A nonprofit, technical professional association based in the United States that develops, among other things, data communication standards.
Internet Protocol. The network layer for the TCP/IP protocol suite widely used on Ethernet networks. (RFC 791).
Inter-Process Communication. Exchange of data between one process and another, either within the same computer or over a network.
IP Security. A protocol that provides security for transmission of sensitive information over unprotected networks such as the Internet.
Integrated Services Digital Network. A set of communications standards allowing a single wire or optical fibre to carry voice, digital network services and video.
International Standards Organisation. A voluntary, non-treaty organisation founded in 1946, responsible for creating international standards in many areas, including computers and communications.
International Telecommunications Union. The ITU-T, the telecommunication standardisation sector of ITU, is responsible for making technical recommendations about telephone and data (including fax) communications systems.
Local Area Network. A data communications network which is geographically limited (typically to a 1 km radius) allowing easy interconnection of terminals, microprocessors and computers within adjacent buildings.
Media Access Control. The lower sublayer of the OSI data link layer. The interface between a node's Logical Link Control and the network's physical layer. A MAC address is the hardware address of a device connected to a shared network medium.
Management Information Base. A database of managed objects accessed by network management protocols.
Multi-Router Traffic Grapher. Tobias Oetiker's network monitoring system [Oetiker, 1998].
Network Interface Controller/Card. An adapter circuit board installed in a computer to provide a physical connection to a network.
Object IDentifier. Generally an implementation-specific integer or pointer that uniquely identifies an object.
Open Standards Interconnect. The umbrella name for a series of non-proprietary protocols and specifications, comprising, among others, the OSI Reference Model, Common Management Information Protocol and Services, and the Network Management Model.
Organisationally Unique Identifier. An OUI or "company id" is a 24 bit globally unique assigned number referenced by various standards. OUI is used in the family of 802 LAN standards, e.g. Ethernet, Token Ring, et cetera [IEEE, 2002].
Rate Adaptive Digital Subscriber Line. A non-standard version of ADSL that allows modems to adapt the rate of transfer to match conditions on the line.
Request For Comments. One of a series, begun in 1969, of numbered Internet informational documents and standards widely followed by commercial software and freeware in the Internet and Unix communities.
Red, Green, Blue. The three colours of light which can be mixed to produce any other colour. Coloured images are often stored as a sequence of RGB triplets or as separate red, green and blue overlays.
Round Robin Database. The database used by Tobias Oetiker's MRTG [Oetiker, 1998].
Simple Object Access Protocol. A minimal set of conventions for invoking code using XML over HTTP.
South East Academic LibrarieS. A library service for the Eastern Cape Higher Educational Association (South Africa).
Standard Generalised Markup Language. A generic markup language for representing documents. SGML is an International Standard that describes the relationship between a document's content and its structure.
Short Message Service. A message service offered by the GSM digital cellular telephone system.
Simple Network Management Protocol. The Internet standard protocol developed to manage nodes on an IP network. (RFC 1157).
Structured Query Language. An industry-standard language for creating, updating and, querying relational database management systems.
Transmission Control Protocol. The most common transport layer protocol used on Ethernet and the Internet. (RFC 793).
TELephone COmpany. A company providing telephone services to end users.
Time To Live. A field in the Internet Protocol header which indicates how many more hops a particular packet should be allowed to make before being discarded or returned.
User Datagram Protocol. An Internet standard network layer, transport layer and session layer protocol which provides simple but unreliable datagram services. (RFC 768).
Universal Resource Identifier. The generic set of all names and addresses which are short strings which refer to objects (typically on the Internet). The most common kinds of URI are URLs and relative URLs.
Uniform Resource Locator. A standard way of specifying the location of an object, typically a web page, on the Internet.
Virtual Local Area Network. A logical grouping of two or more nodes which are not necessarily on the same physical network segment but which share the same network number.
World Wide Web Consortium. The main standards body for the World-Wide Web. W3C works with the global community to establish international standards for client and server protocols that enable on-line commerce and communications on the Internet. It also produces reference software.
Digital Subscriber Line. See DSL.
eXtensible Markup Language. An initiative from the World Wide Web Consortium defining an "extremely simple" dialect of SGML suitable for use on the World-Wide Web.