RFC 1983

Internet Users' Glossary

๐Ÿ“… published August 1996, from ietf

Internet Users' Glossary ๐Ÿฆ‹

Network Working Group, G. Malkin, Editor, Xylogics ๐Ÿ’–

RFC 1983, FYI 18, dated August 1996. It's Informational ๐Ÿ“š and it obsoletes RFC 1392. It doesn't list any updates.


Status of this Memo โœจ

Bestie, this memo is informational. It gives info to the Internet community, but it does not specify an Internet standard of any kind ๐Ÿ™…โ€โ™€๏ธ. Distribution of this memo is unlimited, so share it with everyone ๐ŸŒธ.

Abstract ๐Ÿ’…

There are so many networking glossaries out there, and this one is all about the terms that are specific to the Internet ๐ŸŒ. Obviously there are entries for some basic terms and acronyms too, because other entries refer to them. Gotta have the foundations ๐Ÿงฑ.

Acknowledgements ๐Ÿซถ

This document came from the User Glossary Working Group of the User Services Area of the Internet Engineering Task Force. The author especially wants to thank Ryan Moats/InterNIC for his careful review and his many contributions. Iconic behavior ๐Ÿ‘‘.

Table of Contents ๐Ÿ—‚๏ธ

non-letter  . .  2      I . . . . . . . 26      R . . . . . . . 46
A . . . . . . .  2      J . . . . . . . 33      S . . . . . . . 49
B . . . . . . .  7      K . . . . . . . 33      T . . . . . . . 52
C . . . . . . . 10      L . . . . . . . 33      U . . . . . . . 55
D . . . . . . . 14      M . . . . . . . 35      V . . . . . . . 57
E . . . . . . . 18      N . . . . . . . 39      W . . . . . . . 57
F . . . . . . . 20      O . . . . . . . 42      X . . . . . . . 59
G . . . . . . . 22      P . . . . . . . 43      Y . . . . . . . 60
H . . . . . . . 23      Q . . . . . . . 46      Z . . . . . . . 60

References  . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Security Considerations . . . . . . . . . . . . . . . . . . . . 62
Editor's Address  . . . . . . . . . . . . . . . . . . . . . . . 62

Glossary ๐Ÿ“–

10Base2 Okay so this is a physical layer spec for 10Mbps baseband data over coaxial cable (Thinnet), and the max cable segment length is 200 meters ๐Ÿงต.

10Base5 Same vibe as 10Base2, but this one is for coaxial cable (Thicknet) and the max segment length is 500 meters ๐Ÿ“.

10BaseF A physical layer spec for 10Mbps baseband data over fiber-optic cable โœจ.

10BaseT A physical layer spec for 10Mbps baseband data over twisted-pair copper wire ๐Ÿงก.

802.x The set of IEEE standards that define LAN protocols. See also: IEEE.

822 See: RFC 822

:-) Okay, this little guy is one of the ways you can show "mood" in the super flat medium of computers, using "smiley faces" ๐Ÿ™‚. It's "metacommunication", and there are literally hundreds of these symbols, from the obvious to the obscure ๐Ÿคฏ. This particular one expresses "happiness". Don't see it? Tilt your head to the left 90 degrees ๐Ÿ™ƒ. Smiles are also used to denote sarcasm, so read the room ๐Ÿ’€. [Source: ZEN]

abstract syntax A description of a data structure that doesn't depend on machine-oriented structures and encodings ๐Ÿง . [Source: RFC1208]

Abstract Syntax Notation One (ASN.1) The language the OSI protocols use to describe abstract syntax ๐Ÿ“. It's also used to encode SNMP packets. ASN.1 is defined in ISO documents 8824.2 and 8825.2. See also: Basic Encoding Rules.

Acceptable Use Policy (AUP) Lots of transit networks have policies that restrict what the network can be used for ๐Ÿšง. For example, some networks may only be used for non-commercial purposes. Some AUPs limit the type of material that can be made available to the public (e.g., pornographic material ๐Ÿ™ˆ). Enforcement of AUPs varies from network to network. See also: netiquette.

Access Control List (ACL) Most network security systems work by allowing selective use of services ๐Ÿ”. An Access Control List is the usual way access to services is granted or denied. It's simply a list of the services available, and each service comes with a list of the hosts that are allowed to use it ๐Ÿ“‹.

ACK See: Acknowledgment

acknowledgment (ACK) A message sent to say that a block of data arrived at its destination without error โœ…. See also: Negative Acknowledgement. [Source: NNSC]

ACL See: Access Control List

AD See: Administrative Domain

address Okay, there are four types of addresses that are commonly used on the Internet ๐Ÿ . They are: email address; IP, internet or Internet address; hardware or MAC address; and URL. See also: email address, IP address, internet address, MAC address, Uniform Resource Locator.

address mask A bit mask that identifies which bits in an IP address correspond to the network and subnet portions of the address ๐ŸŽญ. It's often called the subnet mask, because the network portion of the address (the network mask) can be figured out from the encoding built into an IP address. See also: Classless Inter-domain Routing.

address resolution Converting a network-layer address (like an IP address) into the matching physical address (like a MAC address) ๐Ÿ”. See also: IP address, MAC address.

Address Resolution Protocol (ARP) Used to dynamically discover the low-level physical network hardware address that matches the high-level IP address of a given host ๐Ÿ”. ARP is limited to physical network systems that support broadcast packets that every host on the network can hear ๐Ÿ“ก. See also: proxy ARP, Reverse Address Resolution Protocol.

Administrative Domain (AD) A collection of hosts and routers, plus the network(s) that connect them, all managed by one administrative authority ๐Ÿ›๏ธ.

Advanced Research Projects Agency (ARPA) A U.S. Department of Defense agency in charge of developing new technology for the military ๐ŸŽ–๏ธ. ARPA (formerly known as DARPA, nee ARPA) funded a lot of the development of the Internet we know today, including the Berkeley version of Unix and TCP/IP ๐Ÿฆ…. It's literally the reason we have the Internet ๐Ÿ™Œ. [Source: NNSC]

Advanced Research Projects Agency Network (ARPANET) A pioneering longhaul network funded by ARPA ๐Ÿ›ฐ๏ธ. It's retired now, but it was the basis for early networking research and a central backbone while the Internet was being built ๐Ÿ—๏ธ. The ARPANET was made of individual packet switching computers connected by leased lines. See also: Advanced Research Projects Agency. [Source: FYI4]

agent In the client-server model, this is the part of the system that does information preparation and exchange on behalf of a client or server application ๐Ÿ•ต๏ธโ€โ™€๏ธ. [Source: RFC1208]

alias A name that's usually short and easy to remember, and that gets translated into another name that's usually long and hard to remember ๐Ÿ’ซ.

American National Standards Institute (ANSI) This org approves U.S. standards in lots of areas, including computers and communications ๐Ÿ‡บ๐Ÿ‡ธ. Standards it approves are often called ANSI standards (e.g., ANSI C is the version of the C language that ANSI approved) ๐Ÿ“˜. ANSI is a member of ISO. See also: International Organization for Standardization. [Source: NNSC]

American Standard Code for Information Interchange (ASCII) A standard character-to-number encoding that's widely used across the computer industry ๐Ÿ”ข. See also: EBCDIC.

anonymous FTP Anonymous FTP lets you grab documents, files, programs and other archived data from anywhere on the Internet, without needing a userid and password ๐Ÿ“‚. You just use the special userid "anonymous", and you skip the local security checks to get at the publicly accessible files on the remote system ๐Ÿ•Š๏ธ. See also: archive site, File Transfer Protocol, World Wide Web.

ANSI See: American National Standards Institute

API See: Application Program Interface

Appletalk A networking protocol Apple Computer developed for communication between Apple products and other computers ๐ŸŽ. This protocol doesn't depend on the network layer it runs over ๐Ÿงฉ. Current implementations exist for Localtalk, a 235Kb/s local area network, and Ethertalk, a 10Mb/s local area network. [Source: NNSC]

application A program that does a function directly for a user ๐Ÿ’ป. FTP, mail and Telnet clients are examples of network applications.

application layer The top layer of the network protocol stack ๐ŸŽ‚. The application layer deals with the semantics of work (like formatting electronic mail messages). How to represent that data and how to reach the foreign node are issues for the lower layers of the network ๐Ÿ›ค๏ธ. [Source: MALAMUD]

Application Program Interface (API) A set of calling conventions that define how a service is invoked through a software package ๐Ÿ“ž. [Source: RFC1208]

archie A system that automatically gathers, indexes and serves information on the Internet ๐Ÿ—ƒ๏ธ. The first version of archie gave you an indexed directory of filenames from all anonymous FTP archives on the Internet. Later versions provide other collections of information. See also: archive site, Gopher, Prospero, Wide Area Information Servers.

archive site A machine that gives you access to a collection of files across the Internet ๐Ÿ—„๏ธ. For example, an anonymous FTP archive site gives access to archived material through the FTP protocol. WWW servers can also be archive sites. See also: anonymous FTP, archie, Gopher, Prospero, Wide Area Information Servers, World Wide Web.

ARP See: Address Resolution Protocol

ARPA See: Advanced Research Projects Agency

ARPANET See: Advanced Research Projects Agency Network

AS See: Autonomous System

ASCII See: American Standard Code for Information Interchange

ASN.1 See: Abstract Syntax Notation One

assigned numbers This is the RFC [STD2] that documents the currently assigned values from several series of numbers used in network protocol implementations ๐Ÿ”–. It gets updated from time to time, and current info can always be found from the Internet Assigned Numbers Authority (IANA). If you're developing a protocol or application that needs a link, socket, port, protocol, etc., contact the IANA to get a number assigned ๐Ÿ“จ. See also: Internet Assigned Numbers Authority, STD. [Source: STD2]

Asynchronous Transfer Mode (ATM) A standard for high-load, high-speed (1.544Mbps through 1.2Gbps), fixed-size packet (cell) switching with dynamic bandwidth allocation โšก. ATM is also known as "fast packet" ๐ŸŽ๏ธ.

ATM See: Asynchronous Transfer Mode

AUP See: Acceptable Use Policy

authentication Verifying the identity of a person or process ๐Ÿชช. [Source: MALAMUD]

Autonomous System (AS) A collection of routers under a single administrative authority that use a common Interior Gateway Protocol to route packets ๐Ÿ—บ๏ธ.

backbone The top level of a hierarchical network ๐Ÿฆด. Stub and transit networks that connect to the same backbone are guaranteed to be interconnected ๐Ÿ”—. See also: stub network, transit network.

To be continuedโ€ฆ ๐Ÿงšโœจ

bandwidth ๐ŸŽ€ Okay, so technically it's the gap in Hertz (Hz) between the highest and lowest frequencies of a transmission channel. ๐Ÿ’… But in everyday talk, people mean the amount of data that can be sent through a given communications circuit. โœจ

bang path ๐Ÿฆ‹ A series of machine names used to send electronic mail from one user to another, usually by spelling out an explicit UUCP path for the mail to take. See also: email address, mail path, UNIX-to-UNIX CoPy. ๐Ÿงš

baseband ๐ŸŒธ A transmission medium that carries digital signals without any complicated frequency shifting. Generally, only one communication channel is available at any given time. Ethernet is an example of a baseband network. See also: broadband, Ethernet. [Source: NNSC] ๐Ÿ’œ

Basic Encoding Rules (BER) ๐Ÿ“ Standard rules for encoding data units described in ASN.1. People sometimes lump these in under the term ASN.1 by mistake, but ASN.1 properly refers only to the abstract syntax description language, not the encoding technique. See also: Abstract Syntax Notation One. [Source: NNSC] ๐Ÿค“

BBS ๐ŸŒˆ See: Bulletin Board System

BCNU ๐Ÿ™ˆ Be Seein' You ๐Ÿ˜ญ

BCP ๐Ÿ‘‘ The newest subseries of RFCs, written to describe Best Current Practices in the Internet. Rather than specifying a protocol, these documents spell out the best ways to use protocols and the best ways to configure options so that various vendors' products interoperate. BCPs carry the endorsement of the IESG. See also: Request For Comments, Internet Engineering Steering Group. โœจ

BER ๐ŸŒธ See: Basic Encoding Rules

Berkeley Internet Name Daemon (BIND) ๐Ÿ”ฅ An implementation of a DNS server, developed and distributed by the University of California at Berkeley. Lots of Internet hosts run BIND, and it's the ancestor of many commercial BIND implementations. See also: Domain Name System. ๐Ÿ’…

Berkeley Software Distribution (BSD) ๐Ÿฆ‹ An implementation of the UNIX operating system and its utilities, developed and distributed by the University of California at Berkeley. "BSD" is usually preceded by the version number of the distribution, so "4.3 BSD" is version 4.3 of the Berkeley UNIX distribution. Many Internet hosts run BSD software, and it's the ancestor of many commercial UNIX implementations. [Source: NNSC] ๐ŸŽ€

BGP ๐Ÿงš See: Border Gateway Protocol

big-endian ๐Ÿฅš A format for storing or transmitting binary data in which the most significant bit (or byte) comes first. The term comes from "Gulliver's Travels" by Jonathan Swift. The Lilliputians, being very small, had correspondingly small political problems. The Big-Endian and Little-Endian parties debated over whether soft-boiled eggs should be opened at the big end or the little end. ๐Ÿ˜ญ See also: little-endian. [Source: RFC1208] ๐Ÿ’–

binary ๐Ÿค– 11001001

BIND ๐ŸŒธ See: Berkeley Internet Name Daemon

Birds Of a Feather (BOF) ๐Ÿฆ A Birds Of a Feather (flocking together) is an informal discussion group. It's formed, often ad hoc, to consider a specific issue and therefore has a narrow focus. See also: Working Group. ๐Ÿซถ

Bitnet ๐Ÿ’Œ An academic computer network that provides interactive electronic mail and file transfer services, using a store-and-forward protocol based on IBM Network Job Entry protocols. Bitnet-II encapsulates the Bitnet protocol within IP packets and depends on the Internet to route them. ๐ŸŒ

BOF ๐Ÿฆ See: Birds Of a Feather

BOOTP ๐Ÿ’ป The Bootstrap Protocol, described in RFC 1542, is used for booting diskless nodes. See also: Dynamic Host Configuration Protocol, Reverse Address Resolution Protocol. โœจ

Border Gateway Protocol (BGP) ๐ŸŒ‰ The Border Gateway Protocol is an exterior gateway protocol defined in RFC 1771. It's design is based on experience gained with EGP, as defined in RFC 904, and EGP usage in the NSFNET Backbone, as described in RFCs 1092 and 1093. See also: Exterior Gateway Protocol. ๐Ÿ’…

bounce ๐Ÿ“ฌ The return of a piece of mail because of an error in its delivery. [Source: ZEN] ๐Ÿ’€

bridge ๐ŸŒ‰ A device that forwards traffic between network segments based on datalink layer information. These segments would have a common network layer address. See also: gateway, router. ๐Ÿงธ

broadband ๐Ÿ“ก A transmission medium that can support a wide range of frequencies. It can carry multiple signals by dividing the total capacity of the medium into multiple independent bandwidth channels, where each channel operates only on a specific range of frequencies. See also: baseband. ๐ŸŒˆ

broadcast ๐Ÿ“ข A special type of multicast packet that all nodes on the network are always willing to receive. See also: multicast, unicast. ๐Ÿซถ

broadcast storm โ›ˆ๏ธ An incorrect packet broadcast onto a network that causes multiple hosts to respond all at once, typically with equally incorrect packets. That makes the storm grow exponentially in severity. ๐Ÿ˜ฑ See also: Ethernet meltdown.

brouter ๐Ÿงฉ A device that bridges some packets (that is, forwards based on datalink layer information) and routes other packets (that is, forwards based on network layer information). The bridge/route decision is based on configuration information. See also: bridge, router. ๐ŸŽฏ

BSD ๐Ÿฆ‹ See: Berkeley Software Distribution

BTW ๐Ÿ’ฌ By The Way ๐Ÿซถ

Bulletin Board System (BBS) ๐Ÿ—‚๏ธ A computer, and its associated software, that typically provides electronic messaging services, archives of files, and any other services or activities of interest to the bulletin board system's operator. BBSs have traditionally been the domain of hobbyists, but a growing number of them are connected directly to the Internet, and many are currently operated by government, educational, and research institutions. See also: Electronic Mail, Internet, Usenet. [Source: NWNET] ๐ŸŒธ

Campus Wide Information System (CWIS) ๐Ÿซ A CWIS makes information and services publicly available on campus via kiosks, and makes interactive computing available via kiosks, interactive computing systems, and campus networks. Services routinely include directory information, calendars, bulletin boards, and databases. ๐Ÿ“…

CCIRN ๐ŸŒ See: Coordinating Committee for Intercontinental Research Networks

CCITT ๐Ÿ“ž See: Comite Consultatif International de Telegraphique et Telephonique

CERT ๐Ÿšจ See: Computer Emergency Response Team

checksum ๐Ÿ”ข A computed value that depends on the contents of a packet. This value is sent along with the packet when it's transmitted. The receiving system computes a new checksum based on the received data and compares it with the one sent with the packet. If the two values are the same, the receiver has a high degree of confidence that the data was received correctly. See also: Cyclic Redundancy Check. [Source: NNSC] โœ…

CIDR ๐Ÿง See: Classless Inter-domain Routing

circuit switching ๐Ÿ”Œ A communications paradigm in which a dedicated communication path is established between two hosts, and all packets travel on it. The telephone system is an example of a circuit switched network. See also: connection-oriented, connectionless, packet switching. โ˜Ž๏ธ

Classless Inter-domain Routing (CIDR) ๐Ÿ—บ๏ธ A proposal, set forth in RFC 1519, to allocate IP addresses so that the addresses can be aggregated when advertised as routes. It's based on the elimination of intrinsic IP network addresses, meaning the network address isn't determined from the first few bits of the IP address. See also: IP address, network address, supernet. ๐ŸŒŸ

client ๐Ÿ™‹ A computer system or process that requests a service of another computer system or process. A workstation requesting the contents of a file from a file server is a client of the file server. See also: client-server model, server. [Source: NNSC] ๐Ÿ’

client-server model ๐Ÿค A common way to describe the paradigm of many network protocols. Examples include the name-server/name-resolver relationship in DNS and the file-server/file-client relationship in NFS. See also: client, server, Domain Name System, Network File System. ๐Ÿ’–

CNI ๐Ÿ“š See: Coalition for Networked Information

Coalition for Networked Information (CNI) ๐Ÿค A consortium formed by American Research Libraries, CAUSE, and EDUCOM (no, they are not acronyms) to promote the creation of, and access to, information resources in networked environments, in order to enrich scholarship and enhance intellectual productivity. ๐Ÿง 

Comite Consultatif International de Telegraphique et Telephonique (CCITT) ๐Ÿ‡บ๐Ÿ‡ณ This organization is now part of the International Telecommunications Union and is responsible for making technical recommendations about telephone and data communications systems. Every four years CCITT holds plenary sessions where they adopt new standards; the most recent was in 1992. Recently, the ITU reorganized, and CCITT was renamed the ITU-TSS. See also: International Telecommunications Union - Telecommunications Standards Sector. ๐Ÿ—“๏ธ

Computer Emergency Response Team (CERT) ๐Ÿ›ก๏ธ The CERT was formed by ARPA in November 1988 in response to the needs exhibited during the Internet worm incident. The CERT's charter is to work with the Internet community to facilitate its response to computer security events involving Internet hosts, to take proactive steps to raise the community's awareness of computer security issues, and to conduct research targeted at improving the security of existing systems. CERT products and services include 24-hour technical assistance for responding to computer security incidents, product vulnerability assistance, technical documents, and tutorials. In addition, the team maintains a number of mailing lists (including one for CERT Advisories) and provides an anonymous FTP server, at "cert.org", where security-related documents and tools are archived. The CERT may be reached by email at "cert@cert.org" and by telephone at +1-412-268-7090 (24-hour hotline). See also: Advanced Research Projects Agency, worm. ๐Ÿšจโœจ

congestion ๐Ÿšฆ Congestion occurs when the offered load exceeds the capacity of a data communication path. ๐ŸŒŠ

connection-oriented ๐Ÿค The data communication method in which communication proceeds through three well-defined phases: connection establishment, data transfer, and connection release. TCP is a connection-oriented protocol. See also: circuit switching, connectionless, packet switching, Transmission Control Protocol. ๐ŸŽ€

connectionless ๐Ÿ•Š๏ธ The data communication method in which communication occurs between hosts with no previous setup. Packets between two hosts may take different routes, since each is independent of the other. UDP is a connectionless protocol. See also: circuit switching, connection-oriented, packet switching, User Datagram Protocol. ๐Ÿฆ‹

Coordinating Committee for Intercontinental Research Networks (CCIRN) ๐Ÿ’– A committee that includes the United States FNC and its counterparts in North America and Europe. It's co-chaired by the executive directors of the FNC and the European Association of Research Networks (RARE), and it gives the principal North American and European research networking bodies a forum for cooperative planning. See also: Federal Networking Council, RARE. [Source: MALAMUD]

core gateway ๐ŸŒธ Historically, this was one of a set of gateways (routers) run by the Internet Network Operations Center at Bolt, Beranek and Newman (BBN). It was a huge deal for Internet routing, because every group had to advertise paths to its networks from a core gateway. Major main-character energy, ngl. [Source: MALAMUD]

Corporation for Research and Educational Networking (CREN) ๐ŸŽ€ This org was formed in October 1989, when Bitnet and CSNET (Computer + Science NETwork) got merged under one administrative authority. CSNET isn't operational anymore, but CREN still runs Bitnet. See also: Bitnet. [Source: NNSC]

cracker ๐Ÿ’€ A cracker is someone who tries to get into computer systems without authorization. These folks are often malicious, unlike hackers, and they have plenty of ways to break into a system. See also: hacker, Computer Emergency Response Team, Trojan Horse, virus, worm.

CRC See: cyclic redundancy check

CREN See: Corporation for Research and Educational Networking

CU-SeeMe ๐Ÿฆ‹ Pronounced "See you, See me," CU-SeeMe is a publicly available videoconferencing program developed at Cornell University. Anyone with audio/video capabilities and an Internet connection can videoconference with anyone else who has the same capabilities, and it lets multiple people tie into the same videoconference. It's giving group chat, but make it video. ๐Ÿซถ

CWIS See: Campus Wide Information system

Cyberspace ๐ŸŒˆ A term coined by William Gibson in his fantasy novel Neuromancer to describe the "world" of computers, and the society that gathers around them. [Source: ZEN]

Cyclic Redundancy Check (CRC) โœจ This is a number derived from a set of data that's about to be transmitted. The receiving node recalculates the CRC at the remote end and compares it to the value originally transmitted, so it can detect some types of transmission errors. See also: checksum. [Source: MALAMUD]


DANTE ๐Ÿงš A non-profit company founded in July 1993 to help the European research community level up their networking facilities. It focuses on building a high-speed computer network infrastructure.

DARPA Defense Advanced Research Projects Agency. See: Advanced Research Projects Agency

Data Encryption Key (DEK) ๐Ÿ” Used for encrypting message text and for computing message integrity checks (signatures). See also: encryption.

Data Encryption Standard (DES) A popular, standard encryption scheme. See also: encryption, Pretty Good Privacy, RSA.

datagram ๐Ÿ’œ A self-contained, independent entity of data that carries enough information to be routed from the source computer to the destination computer, without relying on earlier exchanges between that source and destination or the transporting network. It's giving independent little packet energy. See also: frame, packet. [Source: J. Postel]

DCA See: Defense Information Systems Agency

DCE Data Circuit-terminating Equipment

DCE See: Distributed Computing Environment

DDN See: Defense Data Network

DDN NIC See: Defense Data Network Network Information Center

DECnet A proprietary network protocol designed by Digital Equipment Corporation. Each Phase of the implementation, such as Phase IV and Phase V, works differently. Phases, babe. ๐Ÿ™ˆ

default route A routing table entry used to direct packets addressed to networks that aren't explicitly listed in the routing table. [Source: MALAMUD]

Defense Data Network (DDN) A global communications network serving the US Department of Defense. It's made up of MILNET, other portions of the Internet, and classified networks that aren't part of the Internet. The DDN connects military installations and is managed by the Defense Information Systems Agency. See also: Defense Information Systems Agency.

Defense Data Network Network Information Center (DDN NIC) ๐ŸŒธ Previously called "The NIC", its main job was assigning Internet network addresses and Autonomous System numbers, administering the root domain, and providing information and support services to the Internet for the DDN. Since the creation of the InterNIC, the DDN NIC only does these things for the DDN. See also: Autonomous System, network address, Internet Registry, InterNIC, Network Information Center, Request For Comments.

Defense Information Systems Agency (DISA) Formerly called the Defense Communications Agency (DCA), this is the government agency in charge of managing the DDN portion of the Internet, including MILNET. Right now, DISA runs the DDN and supports the user assistance services of the DDN NIC. See also: Defense Data Network.

DEK See: Data Encryption Key

DES See: Data Encryption Standard

dialup A temporary, as opposed to dedicated, connection between machines, set up over a phone line (analog or ISDN). See also: Integrated Services Digital Network.

Directory Access Protocol An X.500 protocol used for communication between a Directory User Agent and a Directory System Agent. [Source: MALAMUD]

Directory System Agent (DSA) The software that provides the X.500 Directory Service for a portion of the directory information base. Generally, each DSA is responsible for the directory information of a single organization or organizational unit. [Source: RFC1208]

Directory User Agent (DUA) The software that accesses the X.500 Directory Service on behalf of the directory user. That user may be a person or another software element. [Source: RFC1208]

DISA See: Defense Information Systems Agency

Distributed Computing Environment (DCE) ๐Ÿ‘‘ An architecture of standard programming interfaces, conventions, and server functionalities (for example naming, distributed file system, remote procedure call) for distributing applications transparently across networks of heterogeneous computers. It's promoted and controlled by the Open Software Foundation (OSF), a consortium led by Digital, IBM and Hewlett Packard. [Source: RFC1208]

distributed database A collection of several different data repositories that looks like a single database to the user. A prime example on the Internet is the Domain Name System.

DIX Ethernet See: Ethernet

DNS See: Domain Name System

domain ๐Ÿ™„ "Domain" is a heavily overused term on the Internet. It can be used in the Administrative Domain context or the Domain Name context. See also: Administrative Domain, Domain Name System.

Domain Name System (DNS) ๐Ÿ“ The DNS is a general purpose, distributed, replicated, data query service. Its principal use is looking up host IP addresses based on host names. The style of host names now used on the Internet is called "domain name", because it's the style of name used to look up anything in the DNS. Some important domains are .COM (commercial), .EDU (educational), .NET (network operations), .GOV (U.S. government), and .MIL (U.S. military). Most countries also have a domain. Country domain names are based on ISO 3166, for example .US (United States), .UK (United Kingdom), and .AU (Australia). See also: Fully Qualified Domain Name, Mail Exchange Record.

dot address (dotted decimal notation) An IP address written in the common notation A.B.C.D, where each letter stands for one byte of a four byte IP address, shown in decimal. See also: IP address. [Source: FYI4]

DSA See: Directory System Agent

DTE Data Terminal Equipment

DUA See: Directory User Agent

dynamic adaptive routing Automatic rerouting of traffic based on sensing and analysis of current actual network conditions. NOTE: this does not include cases of routing decisions made from predefined information. [Source: J. Postel]

E1 The basic building block for European multi-megabit data rates, with a bandwidth of 2.048Mbps. See also: T1.

E3 A European standard for transmitting data at 57.344Mbps. See also: T3.

EARN European Academic and Research Network. See: Trans-European Research and Education Networking Association.

EBCDIC See: Extended Binary Coded Decimal Interchange Code

Ebone A pan-European backbone service. ๐ŸŒ

EFF See: Electronic Frontier Foundation

EGP See: Exterior Gateway Protocol

Electronic Frontier Foundation (EFF) โญ A foundation established to address the social and legal issues that come up as computers become more and more pervasive as a means of communication and information distribution.

Electronic Mail (email) ๐Ÿ’Œ A system where a computer user can exchange messages with other computer users (or groups of users) over a communications network. It's one of the most popular uses of the Internet. [Source: NNSC]

email See: Electronic mail

email address The domain-based or UUCP address used to send electronic mail to a specified destination. For example, an editor's address is gmalkin@xylogics.com. See also: bang path, mail path, UNIX-to-UNIX CoPy. [Source: ZEN]

encapsulation ๐ŸŽ The technique layered protocols use, where a layer adds header information to the protocol data unit (PDU) it gets from the layer above. For example, in Internet terminology, a packet would contain a header from the physical layer, followed by a header from the datalink layer (e.g. Ethernet), followed by a header from the network layer (IP), followed by a header from the transport layer (e.g. TCP), followed by the application protocol data. [Source: RFC1208]

encryption Encryption is the manipulation of a packet's data so that nobody except the intended recipient can read it. There are many types of data encryption, and they're the basis of network security. See also: Data Encryption Standard.

error checking The examination of received data for transmission errors. See also: checksum, Cyclic Redundancy Check.

Ethernet A 10-Mb/s standard for LANs, initially developed by Xerox and later refined by Digital, Intel and Xerox (DIX). All hosts are connected to a coaxial cable, where they contend for network access using a Carrier Sense Multiple Access with Collision Detection (CSMA/CD) paradigm. See also: 802.x, Local Area Network, token ring.

Ethernet meltdown ๐Ÿ’€ An event that causes saturation, or near saturation, on an Ethernet. It usually results from illegal or misrouted packets, and it typically lasts only a short time. Bestie, it's the network version of everyone talking at once. See also: broadcast storm. [Source: COMER]

Extended Binary Coded Decimal Interchange Code (EBCDIC)

okay so EBCDIC is a character-to-number encoding that's mainly used on IBM computer systems ๐Ÿ’ป it's basically ASCII's cousin who went to a different school ๐ŸŽ€ See also: ASCII.

Exterior Gateway Protocol (EGP)

EGP is the protocol that hands out routing information to the routers which connect autonomous systems ๐Ÿฆ‹ "gateway" is kinda vintage now, "router" is the word everyone uses. ALSO there's a different routing protocol that's also called EGP, defined in RFC 904, so yes, twins ๐Ÿ™ˆ See also: Autonomous System, Border Gateway Protocol, Interior Gateway Protocol.

eXternal Data Representation (XDR)

XDR is a standard for machine-independent data structures, developed by Sun Microsystems and defined in RFCs 1014 and 1832 โœจ it's giving ASN.1 energy, honestly. See also: Abstract Syntax Notation One. [Source: RFC1208]

FARNET

A non-profit corporation, established in 1987, whose whole mission is to advance the use of computer networks to improve research and education ๐ŸŒˆ very much a good-girl-of-the-internet move ๐Ÿซถ

FAQ

Frequently Asked Question. Literally the most relatable acronym ๐Ÿ˜ญ

FDDI

See: Fiber Distributed Data Interface

Federal Information Exchange (FIX)

One of the connection points between the American governmental internets and the Internet ๐Ÿ”Œ [Source: SURA]

Federal Networking Council (FNC)

The coordinating group of representatives from the federal agencies that are involved in developing and using federal networking, especially networks that use TCP/IP and the Internet ๐Ÿ›๏ธ current members include representatives from DOD, DOE, ARPA, NSF, NASA, and HHS. See also: Advanced Research Projects Agency, National Science Foundation.

Fiber Distributed Data Interface (FDDI)

A high-speed (100Mb/s) LAN standard ๐Ÿš€ the underlying medium is fiber optics, and the topology is a dual-attached, counter-rotating token ring. See also: Local Area Network, token ring. [Source: RFC1208]

file transfer

Copying a file from one computer to another over a computer network ๐Ÿ“ See also: File Transfer Protocol, Kermit, Gopher, World Wide Web.

File Transfer Protocol (FTP)

FTP lets a user on one host access another host over a network, and transfer files to and from it ๐Ÿ“ค also, FTP is usually the name of the program the user runs to use the protocol, so it wears two hats ๐ŸŽฉ See also: anonymous FTP.

finger

finger is a protocol, defined in RFC 1288, that lets you retrieve information about a system or a user on a system ๐Ÿ” the word also refers to the commonly used program that does the retrieving. You can get info about all logged-in users, as well as info about specific users, from local or remote systems. Some sites think finger is a security risk, so they've either turned it off or swapped it for a simple message ๐Ÿ™…โ€โ™€๏ธ

FIX

See: Federal Information Exchange

flame

A strong opinion and/or criticism of something, usually a frank, inflammatory statement, in an electronic mail message ๐Ÿ”ฅ it's common to warn people before a flame with an indication of pending fire, like FLAME ON!. Flame wars happen when people start flaming other people for flaming when they shouldn't have. (the drama is unmatched ๐Ÿ’€) See also: Electronic Mail, Usenet.

FLEA

See: Four Letter Extended Acronym

FNC

See: Federal Networking Council

Four Letter Extended Acronym (FLEA)

A recognition of the fact that there are far too many TLAs ๐Ÿ™ƒ See also: Three Letter Acronym.

FQDN

See: Fully Qualified Domain Name

fragment

A piece of a packet ๐Ÿงฉ when a router is forwarding an IP packet to a network whose maximum transmission unit is smaller than the packet size, it's forced to break that packet into multiple fragments. Those fragments get reassembled by the IP layer at the destination host. See also: Maximum Transmission Unit.

fragmentation

The IP process in which a packet is broken into smaller pieces to fit the requirements of a physical network the packet has to pass over โœ‚๏ธ See also: reassembly.

frame

A frame is a datalink layer "packet" that contains the header and trailer information the physical medium needs ๐Ÿ“ฆ basically, network layer packets get encapsulated to become frames. See also: datagram, encapsulation, packet.

freenet

A community-based bulletin board system with email, information services, interactive communications, and conferencing ๐ŸŒป freenets are funded and run by individuals and volunteers, which in one sense makes them like public television ๐Ÿ“บ they're part of the National Public Telecomputing Network (NPTN), an organization based in Cleveland, Ohio, that's devoted to making computer telecommunication and networking services as freely available as public libraries. [Source: LAQUEY]

FTP

See: File Transfer Protocol

Fully Qualified Domain Name (FQDN)

The FQDN is the full name of a system, not just its hostname ๐Ÿ—บ๏ธ for example, venera is a hostname and venera.isi.edu is an FQDN. See also: hostname, Domain Name System.

FYI

For Your Information ๐Ÿ’Œ

FYI

A subseries of RFCs that aren't technical standards or protocol descriptions ๐Ÿ“š FYIs share general information about topics related to TCP/IP or the Internet. See also: Request For Comments.

gated

Gatedaemon ๐Ÿšช a program that supports multiple routing protocols and protocol families. It can be used for routing, and it makes a super effective platform for routing protocol research ๐Ÿ”ฌ the software is freely available by anonymous FTP from gated.cornell.edu. Pronounced gate-dee. See also: Exterior Gateway Protocol, Open Shortest-Path First, Routing Information Protocol, routed.

gateway

The term "router" is now used in place of the original definition of "gateway" ๐ŸŒท today, a gateway is a communications device or program that passes data between networks with similar functions but dissimilar implementations. Don't mix this up with a protocol converter! By this definition, a router is a layer 3 (network layer) gateway, and a mail gateway is a layer 7 (application layer) gateway. See also: mail gateway, router, protocol converter.

Gopher

A distributed information service, developed at the University of Minnesota, that makes hierarchical collections of information available across the Internet ๐Ÿฟ๏ธ Gopher uses a simple protocol, defined in RFC 1436, that lets a single Gopher client access information from any accessible Gopher server, giving the user one single "Gopher space" of information. Public domain versions of the client and server are available. See also: archie, archive site, Prospero, Wide Area Information Servers.

GOSIP

See: Government OSI Profile

Government OSI Profile (GOSIP)

A subset of OSI standards specific to U.S. Government procurements ๐Ÿ‡บ๐Ÿ‡ธ it's designed to maximize interoperability in areas where plain OSI standards are ambiguous or allow too many options.

hacker

A person who delights in having an intimate understanding of the internal workings of a system, computers and computer networks in particular ๐Ÿง  the term is often misused in a negative context, where "cracker" would be the correct term. See also: cracker.

header

The portion of a packet, preceding the actual data, that contains source and destination information ๐ŸŽ it may also contain error checking and other fields. A header is also the part of an electronic mail message that comes before the body and contains, among other things, the message originator, date, and time. See also: Electronic Mail, packet, error checking.

heterogeneous network

A network running multiple network layer protocols ๐ŸŒˆ See also: DECnet, IP, IPX, XNS, homogeneous network.

hierarchical routing

Routing on large networks is a complex problem, but it can be simplified by reducing the size of the networks ๐Ÿชœ this is done by breaking a network into a hierarchy of networks, where each level is responsible for its own routing. The Internet has, basically, three levels: the backbones, the mid-levels, and the stub networks. The backbones know how to route between the mid-levels, the mid-levels know how to route between the sites, and each site (being an autonomous system) knows how to route internally. See also: Autonomous System, Exterior Gateway Protocol, Interior Gateway Protocol, stub network, transit network.

High Performance Computing and Communications (HPCC)

High performance computing covers advanced computing, communications, and information technologies ๐Ÿš€ that includes scientific workstations, supercomputer systems, high speed networks, special purpose and experimental systems, the new generation of large scale parallel systems, and application and systems software, with all the components well integrated and linked over a high speed network. [Source: HPCC]

High Performance Parallel Interface (HIPPI)

An emerging ANSI standard that extends the computer bus over fairly short distances at speeds of 800 and 1600 Mb/s โšก HIPPI is often used in a computer room to connect a supercomputer to routers, frame buffers, mass-storage peripherals, and other computers. See also: American National Standards Institute [Source: MALAMUD]

HIPPI

See: High Performance Parallel Interface

HTML

See: Hypertext Markup Language

homogeneous network

A network running a single network layer protocol ๐ŸŽฏ See also: DECnet, IP, IPX, XNS, heterogeneous network.

hop

A term used in routing ๐Ÿฆ˜ a path to a destination on a network is a series of hops, through routers, away from the origin.

host

A computer that lets users communicate with other host computers on a network ๐Ÿ’ป individual users do this by using application programs, such as electronic mail, Telnet, and FTP. [Source: NNSC]

host address

See: internet address

hostname

The name given to a machine ๐Ÿท๏ธ See also: Fully Qualified Domain Name. [Source: ZEN]

host number

See: host address

HPCC

See: High Performance Computing and Communications

HTTP

See: Hypertext Transfer Protocol

hub

A device connected to several other devices ๐Ÿ›ž in ARCnet, a hub is used to connect several computers together. In a message handling service, a hub is used to transfer messages across the network. [Source: MALAMUD]

hyperlink

A pointer within a hypertext document that points (links) to another document, which may or may not also be a hypertext document ๐Ÿ”— See also: hypertext.

hypertext

A document, written in HTML, that contains hyperlinks to other documents, which may or may not also be hypertext documents ๐Ÿ“– hypertext documents are usually retrieved using WWW. See also: hyperlink, Hypertext Markup Language, World Wide Web.

Hypertext Markup Language (HTML)

The language used to create hypertext documents โœ๏ธ it's a subset of SGML and includes the mechanisms to establish hyperlinks to other documents. See also: hypertext, hyperlink, Standardized General Markup Language.

Hypertext Transfer Protocol (HTTP)

The protocol used by WWW to transfer HTML files ๐ŸŒ a formal standard is still under development in the IETF. See also: hyperlink, hypertext, Hypertext Markup Language, World Wide Web. ๐Ÿ’–

I-D ๐Ÿ’Œ See: Internet-Draft

IAB ๐Ÿ›๏ธ See: Internet Architecture Board

IANA ๐Ÿ—‚๏ธ See: Internet Assigned Numbers Authority

ICMP ๐Ÿ“จ See: Internet Control Message Protocol

IEEE โšก Institute of Electrical and Electronics Engineers

IEEE 802 ๐Ÿงต See: 802.x

IEN ๐Ÿ“œ See: Internet Experiment Note

IEPG ๐Ÿ—บ๏ธ See: Internet Engineering Planning Group

IESG ๐Ÿ‘‘ See: Internet Engineering Steering Group

IETF ๐ŸŒธ See: Internet Engineering Task Force

IINREN ๐ŸŒ See: Interagency Interim National Research and Education Network

IGP ๐Ÿงญ See: Interior Gateway Protocol

IMHO ๐Ÿ’€ In My Humble Opinion. Iconic, and a total classic ๐Ÿ™ˆ

IMR ๐Ÿ“… See: Internet Monthly Report

Integrated Services Digital Network (ISDN) ๐Ÿ“ž Okay so ISDN is an emerging tech that the telephone carriers of the world are starting to offer. It squishes voice and digital network services together into one medium, so you can get digital data services AND voice connections through a single "wire" ๐Ÿงต. The standards that define ISDN are specified by CCITT. See also: CCITT. [Source: RFC1208]

Interagency Interim National Research and Education Network (IINREN) ๐ŸŒˆ An evolving operating network system. Near term (1992-1996) research and development activities will help it smoothly evolve into the future gigabit NREN โญ. [Source: HPCC]

Interior Gateway Protocol (IGP) ๐Ÿงญ A protocol that distributes routing information to the routers within an autonomous system. Fun fact: "gateway" is the historical word, and "router" is the preferred term now ๐Ÿงš. See also: Autonomous System, Exterior Gateway Protocol, Open Shortest-Path First, Routing Information Protocol.

Intermediate System (IS) ๐Ÿ”€ An OSI system that does network layer forwarding. It's basically the OSI version of an IP router ๐Ÿ’…. See also: Open Systems Interconnection, router.

Intermediate System-Intermediate System (IS-IS) ๐Ÿ›ฃ๏ธ The OSI IGP. See also: Open Systems Interconnection, Interior Gateway Protocol.

International Organization for Standardization (ISO) ๐ŸŒ A voluntary, nontreaty organization founded in 1946 that creates international standards in lots of areas, including computers and communications. Its members are the national standards organizations of the 89 member countries, including ANSI for the U.S. See also: American National Standards Institute, Open Systems Interconnection. [Source: TAN]

International Telecommunications Union (ITU) ๐Ÿ“ก A UN agency that coordinates the different national telecommunications standards so that people in one country can communicate with people in another country. Bridging the gap, bestie ๐Ÿซถ

International Telecommunications Union - Telecommunications Standards Sector (ITU-TSS) ๐Ÿ”„ The new name for CCITT since the ITU reorganization. The function is the same. Only the name changed ๐Ÿ’–

internet ๐Ÿ•ธ๏ธ While an internet is a network, people usually use the term "internet" to mean a collection of networks linked together with routers. See also: network.

Internet ๐ŸŒŽ (note the capital "I") The Internet is the largest internet in the world, no cap ๐Ÿ‘‘. It's a three level hierarchy made of backbone networks (e.g. Ultranet), mid-level networks (e.g., NEARnet), and stub networks. The Internet is a multiprotocol internet. See also: backbone, mid-level network, stub network, transit network, Internet Protocol.

internet address ๐Ÿ  An IP address that uniquely identifies a node on an internet. An Internet address (capital "I") uniquely identifies a node on the Internet. See also: internet, Internet, IP address.

Internet Architecture Board (IAB) ๐ŸŽญ

The IAB has been a lot of things over the years. It was originally the Internet Activities Board, and it was responsible for developing the protocols that make up the Internet. Later it changed its name and charter to become the group most responsible for the architecture of the Internet, leaving the protocol details to the IESG. In June of 1992, it was chartered as a component of the Internet Society, and that's the charter it holds today ๐ŸŒŸ. The IAB is responsible for approving nominations to the IESG, architectural oversight for Internet Standard Protocols, IETF standards process oversight and appeals, IANA and RFC activities, and liaison to peer standards groups (e.g., ISO). See also: Internet Engineering Task Force, Internet Research Task Force, Internet Engineering Steering Group, Internet Assigned Numbers Authority, Request for Comments.

Internet Assigned Numbers Authority (IANA) ๐Ÿ—ƒ๏ธ The central registry for lots of Internet protocol parameters, like port, protocol and enterprise numbers, and options, codes and types. The currently assigned values are listed in the "Assigned Numbers" document [STD2]. To request a number assignment, contact the IANA at iana@isi.edu. See also: assigned numbers, STD.

Internet Control Message Protocol (ICMP) ๐Ÿšจ ICMP is an extension to the Internet Protocol. It allows for the generation of error messages, test packets and informational messages related to IP. [Source: FYI4]

Internet-Draft (I-D) ๐Ÿ“ Internet-Drafts are working documents of the IETF, its Areas, and its Working Groups. As the name implies, they're draft documents. They're valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time โณ. Very often, I-Ds are precursors to RFCs. See also: Internet Engineering Task Force, Request For Comments.

Internet Engineering Planning Group (IEPG) ๐Ÿซถ A group, mostly made up of Internet service operators, whose goal is to promote a globally coordinated Internet operating environment. Membership is open to all!

Internet Engineering Steering Group (IESG) ๐Ÿ‘‘ The IESG is made up of the IETF Area Directors and the IETF Chair. It gives the first technical review of Internet standards and is responsible for day-to-day "management" of the IETF. See also: Internet Engineering Task Force.

Internet Engineering Task Force (IETF) ๐Ÿค The IETF is a big, open community of network designers, operators, vendors, and researchers. Its purpose is to coordinate the operation, management and evolution of the Internet, and to resolve short-range and mid-range protocol and architectural issues. It's a major source of proposals for protocol standards, which get submitted to the IAB for final approval. The IETF meets three times a year, and extensive minutes are included in the IETF Proceedings. See also: Internet, Internet Architecture Board. [Source: FYI4]

Internet Experiment Note (IEN) ๐Ÿ“š A series of reports relevant to the Internet. IENs were published in parallel to RFCs and were meant to be "working documents." They've been replaced by Internet-Drafts and are now of historic value only. See also: Internet-Draft, Request For Comments.

Internet Monthly Report (IMR) ๐Ÿ“… Published monthly, the Internet Monthly Reports exist to tell the Internet Research Group about the accomplishments, milestones reached, or problems discovered by the participating organizations.

internet number ๐Ÿ”ข See: internet address

Internet Protocol (IP, IPv4) ๐Ÿ“ฆ The Internet Protocol (version 4), defined in RFC 791, is the network layer for the TCP/IP Protocol Suite. It's a connectionless, best-effort packet switching protocol. See also: packet switching, TCP/IP Protocol Suite, Internet Protocol Version 6.

Internet Protocol Version 6 (IPng, IPv6) โœจ IPv6 (version 5 is a stream protocol used for special applications) is a new version of the Internet Protocol, designed to be an evolutionary step from its predecessor, version 4. There are many RFCs defining various parts of the protocol, its auxiliary protocols, and the transition plan from IPv4. The core RFCs are 1883 through 1886. The name IPng (IP next generation) is a nod to STNG (Star Trek Next Generation) ๐Ÿ––.

Internet Registry (IR) ๐Ÿ—๏ธ The IANA has the discretionary authority to delegate portions of its responsibility. For network address and Autonomous System identifiers, it has handed that responsibility to an IR. The IR function is performed by the DDN NIC. See also: Autonomous System, network address, Defense Data Network..., Internet Assigned Numbers Authority.

Internet Relay Chat (IRC) ๐Ÿ’ฌ A world-wide "party line" protocol that lets you converse with others in real time. IRC is structured as a network of servers, each of which accepts connections from client programs, one per user. See also: talk. [Source: HACKER]

Internet Research Steering Group (IRSG) ๐Ÿง  The "governing body" of the IRTF. See also: Internet Research Task Force. [Source: MALAMUD]

Internet Research Task Force (IRTF) ๐Ÿ”ฌ The IRTF is chartered by the IAB to consider long-term Internet issues from a theoretical point of view. It has Research Groups, similar to IETF Working Groups, each tasked with discussing different research topics. Multi-cast audio/video conferencing and privacy enhanced mail are samples of IRTF output. See also: Internet Architecture Board, Internet Engineering Task Force, Privacy Enhanced Mail.

Internet Society (ISOC) ๐ŸŒ The Internet Society is a non-profit, professional membership organization that facilitates and supports the technical evolution of the Internet. It stimulates interest in, and educates the scientific and academic communities, industry and the public about, the technology, uses and applications of the Internet, and it promotes the development of new applications for the system. The Society provides a forum for discussion and collaboration in the operation and use of the global Internet infrastructure. The Internet Society publishes a quarterly newsletter, the Internet Society News, and holds an annual conference, INET. The development of Internet technical standards takes place under the auspices of the Internet Society, with substantial support from the Corporation for National Research Initiatives under a cooperative agreement with the US Federal Government. [Source: V. Cerf]

Internetwork Packet eXchange (IPX) ๐Ÿฆ– Novell's protocol used by Netware. A router with IPX routing can interconnect LANs so that Novell Netware clients and servers can communicate. See also: Local Area Network.

InterNIC ๐Ÿงš A five year project, partially supported by the National Science Foundation, to provide network information services to the networking community. The InterNIC began operations in April of 1993 and is now a collaborative project of two organizations: AT&T, which provides Directory and Database Services from South Plainsfield, NJ; and Network Solutions, Inc., which provides Registration Services from their headquarters in Herndon, VA. Services are provided via the Internet, and by telephone, FAX, and hardcopy.

interoperability ๐Ÿ”ฅ The ability of software and hardware on multiple machines from multiple vendors to communicate meaningfully. That's the whole vibe ๐Ÿ’œ

IP (IPv4) ๐Ÿ’… See: Internet Protocol

IPng (IPv6) ๐Ÿงš See: Internet Protocol Version 6 โœจ

IP address ๐ŸŽ€ The 32-bit address defined by the Internet Protocol in RFC 791. It's usually written in dotted decimal notation. See also: dot address, internet address, Internet Protocol, network address, subnet address, host address.

IP datagram ๐Ÿง See: datagram

IPX ๐Ÿฆ‹ See: Internetwork Packet eXchange

IR See: Internet Registry

IRC ๐Ÿ’ฌ See: Internet Relay Chat

IRSG See: Internet Research Steering Group

IRTF See: Internet Research Task Force

IS See: Intermediate System

IS-IS See: Intermediate System-Intermediate System

ISDN See: Integrated Services Digital Network

ISO See: International Organization for Standardization

ISO Development Environment (ISODE) ๐Ÿงฉ Software that lets OSI services use a TCP/IP network. Pronounced eye-so-dee-eee. See also: Open Systems Interconnection, TCP/IP Protocol Suite.

ISOC See: Internet Society

ISODE See: ISO Development Environment

ITU See: International Telecommunications Union - Telecommunications Standards Sector

ITU-TSS See: International Telecommunications Union

JKREY ๐ŸŒธ Joyce K. Reynolds

KA9Q ๐Ÿ“ป A popular implementation of TCP/IP and associated protocols for amateur packet radio systems. See also: TCP/IP Protocol Suite. [Source: RFC1208]

Kerberos ๐Ÿ” The security system of MIT's Project Athena. It's based on symmetric key cryptography. See also: encryption.

Kermit ๐Ÿธ A popular file transfer protocol developed by Columbia University. Because Kermit runs in most operating environments, it gives you an easy method of file transfer. Kermit is not the same as FTP. See also: File Transfer Protocol [Source: MALAMUD]

Knowbot ๐Ÿค– A "Knowledge Robot" is a program that seeks out information based on specified criteria. "Knowbot," as trademarked by CNRI, refers specifically to the search engine for Knowbot Information Services. See also: Corporation for National Research Initiatives, X.500, white pages, whois, netfind.

Knowbot Information Services ๐Ÿ” An experimental directory service. See also: white pages, whois, X.500.

LAN See: Local Area Network


layer ๐Ÿฐ Communication networks for computers may be organized as a set of more or less independent protocols, each in a different layer (also called level). The lowest layer governs direct host-to-host communication between the hardware at different hosts, and the highest consists of user applications. Each layer builds on the layer beneath it. For each layer, programs at different hosts use protocols appropriate to that layer to communicate with each other. TCP/IP has five layers of protocols; OSI has seven. The advantage of different layers of protocols is that the methods of passing information from one layer to another are specified clearly as part of the protocol suite, and changes within a protocol layer are prevented from affecting the other layers. This greatly simplifies the task of designing and maintaining communication programs. See also: Open Systems Interconnection, TCP/IP Protocol Suite.

LDAP See: Lightweight Directory Access Protocol

Lightweight Directory Access Protocol ๐Ÿชถ This protocol provides access for management and browser applications that offer read/write interactive access to the X.500 Directory. See also: X.500.

link ๐Ÿ”— A pointer that may be used to retrieve the file or data it points to.

list server ๐Ÿ“ฌ An automated mailing list distribution system. List servers handle the administrivia of mailing list maintenance, such as adding and deleting list members.

little-endian ๐Ÿง  A format for storing or transmitting binary data in which the least significant byte (bit) comes first. See also: big-endian. [Source: RFC1208]

LLC See: Logical Link Control

Local Area Network (LAN) ๐Ÿ  A data network intended to serve an area of only a few square kilometers or less. Because the network is known to cover only a small area, optimizations can be made in the network signal protocols that permit data rates up to 100Mb/s. See also: Ethernet, Fiber Distributed Data Interface, token ring, Metropolitan Area Network, Wide Area Network. [Source: NNSC]

Logical Link Control (LLC) ๐Ÿงต The upper portion of the datalink layer, as defined in IEEE 802.2. The LLC sublayer presents a uniform interface to the user of the datalink service, usually the network layer. Beneath the LLC sublayer is the MAC sublayer. See also: 802.x, layer, Media Access Control.

Lurking ๐Ÿ‘€ No active participation on the part of a subscriber to a mailing list or USENET newsgroup. Someone who is lurking is just listening to the discussion. Lurking is encouraged for beginners who need to get up to speed on the history of the group. See also: Electronic Mail, mailing list, Usenet. [Source: LAQUEY]

Lycos ๐Ÿ•ท๏ธ Lycos, Inc. is a new venture formed in late June 1995 to develop and market the Lycos technology originally developed under the direction of Dr. Michael ("Fuzzy") Mauldin at Carnegie Mellon University. The part of Lycos you see when you do a search is the search engine. "Lycos" comes from Lycosidae, a cosmopolitan family of relatively large active ground spiders (Wolf Spiders) that catch their prey by pursuit, rather than in a web. [Source: Lycos's FAQ]

MAC See: Media Access Control

MAC address ๐Ÿชช The hardware address of a device connected to a shared media. See also: Media Access Control, Ethernet, token ring. [Source: MALAMUD]

mail bridge ๐ŸŒ‰ A mail gateway that forwards electronic mail between two or more networks while ensuring that the messages it forwards meet certain administrative criteria. A mail bridge is simply a specialized form of mail gateway that enforces an administrative policy with regard to what mail it forwards. See also: Electronic Mail, mail gateway. [Source: NNSC]

Mail Exchange Record (MX Record) ๐Ÿ“ฎ A DNS resource record type indicating which host can handle mail for a particular domain. See also: Domain Name System, Electronic Mail. [Source: MALAMUD]

mail exploder ๐Ÿ’Œ Part of an electronic mail delivery system that allows a message to be delivered to a list of addresses. Mail exploders are used to implement mailing lists. Users send messages to a single address, and the mail exploder takes care of delivery to the individual mailboxes in the list. See also: Electronic Mail, email address, mailing list. [Source: RFC1208]

mail gateway ๐Ÿšช A machine that connects two or more electronic mail systems (including dissimilar mail systems) and transfers messages between them. Sometimes the mapping and translation can be quite complex, and it generally requires a store-and-forward scheme, whereby the message is received from one system completely before it is transmitted to the next system, after suitable translations. See also: Electronic Mail. [Source: RFC1208]

mail path ๐Ÿ›ค๏ธ A series of machine names used to direct electronic mail from one user to another. This system of email addressing has been used primarily in UUCP networks, which are trying to eliminate its use altogether. See also: bang path, email address, UNIX-to-UNIX CoPy.

mail server ๐Ÿ—‚๏ธ A software program that distributes files or information in response to requests sent via email. Internet examples include Almanac and netlib. Mail servers have also been used in Bitnet to provide FTP-like services. See also: Bitnet, Electronic Mail, FTP. [Source: NWNET]

mailing list ๐Ÿ“ฃ A list of email addresses, used by a mail exploder, to forward messages to groups of people. Generally, a mailing list is used to discuss a certain set of topics, and different mailing lists discuss different topics. A mailing list may be moderated. This means that messages sent to the list are actually sent to a moderator, who determines whether or not to send the messages on to everyone else. Requests to subscribe to, or leave, a mailing list ALWAYS should be sent to the list's "-request" address (e.g. ietf-request@cnri.reston.va.us for the IETF mailing list) or majordomo server. See also: Electronic Mail, mail exploder, email address, moderator, majordomo.

majordomo ๐Ÿคต A program which handles mailing list maintenance (affectionately known as administrivia), such as adding and removing addresses from mailing lists. See also: email address, mailing list.

MAN See: Metropolitan Area Network

Management Information Base (MIB) ๐Ÿ“Š The set of parameters an SNMP management station can query or set in the SNMP agent of a network device (e.g. router). Standard, minimal MIBs have been defined, and vendors often have Private enterprise MIBs. In theory, any SNMP manager can talk to any SNMP agent with a properly defined MIB. See also: client-server model, Simple Network Management Protocol. [Source: BIG-LAN]

Martian ๐Ÿ‘ฝ A humorous term applied to packets that turn up unexpectedly on the wrong network because of bogus routing entries. It's also used as a name for a packet which has an altogether bogus (non-registered or ill-formed) internet address. [Source: RFC1208]

Maximum Transmission Unit (MTU) ๐Ÿ“ The largest frame length which may be sent on a physical medium. See also: frame, fragment, fragmentation.

mbone ๐ŸŽ™๏ธ The Multicast Backbone is based on IP multicasting using class-D addresses. The mbone concept was adopted at the March 1992 IETF in San Diego, during which it was used to audiocast to 40 people throughout the world. At the following meeting, in Cambridge, the name mbone was adopted. Since then, the audiocast has become full two-way audio/video conferencing, using two video channels, four audio channels, and involving hundreds of remote users. See also: multicast, Internet Engineering Task Force.

MD-2, MD-4, MD-5 See: Message Digest

Media Access Control (MAC) ๐Ÿงฑ The lower portion of the datalink layer. The MAC differs for various physical media. See also: MAC Address, Ethernet, Logical Link Control, token ring.

Message Digest (MD-2, MD-4, MD-5) ๐Ÿ” Message digests are algorithmic operations, generally performed on text, which produce a unique signature for that text. MD-2, described in RFC 1319; MD-4, described in RFC 1320; and MD-5, described in RFC 1321, all produce a 128-bit signature. They differ in their operating speed and their resistance to crypto-analytic attack. Generally, one must be traded off for the other.

message switching See: packet switching

Metropolitan Area Network (MAN) ๐Ÿ™๏ธ A data network intended to serve an area approximating that of a large city. Such networks are being implemented by innovative techniques, such as running fiber cables through subway tunnels. A popular example of a MAN is SMDS. See also: Local Area Network, Switched Multimegabit Data Service, Wide Area Network. [Source: NNSC]

MIB See: Management Information Base

Microcom Networking Protocol (MNP) ๐Ÿ’พ okay so this is a whole series of protocols built into most modems that error-check or compress data being sent over a phone line. Basically the behind-the-scenes crew keeping your data clean โœจ

mid-level network ๐ŸŒˆ Mid-level networks (a.k.a. regionals) make up the second level of the Internet hierarchy. They're the transit networks that connect the stub networks to the backbone networks, so they're the middle girlies of the whole setup ๐Ÿซถ See also: backbone, Internet, stub network, transit network.

MIME โ€” See: Multipurpose Internet Mail Extensions

MNP โ€” See: Microcom Networking Protocol

moderator ๐Ÿ‘‘ A person, or small group of people, who manage moderated mailing lists and newsgroups. Moderators are the ones responsible for deciding which email submissions get passed on to the list. Main character energy, fr. See also: Electronic Mail, mailing list, Usenet.

MOSPF โ€” Multicast Open Shortest-Path First. See: Open Shortest-Path First.

MTU โ€” See: Maximum Transmission Unit

MUD โ€” See: Multi-User Dungeon

multicast ๐Ÿฆ‹ A packet with a special destination address that multiple nodes on the network may be willing to receive. See also: broadcast, unicast.

multihomed host ๐Ÿงš A host that has more than one connection to a network. The host may send and receive data over any of the links, but it won't route traffic for other nodes. It's giving "popular, but not a delivery service" ๐Ÿ’€ See also: host, router. [Source: MALAMUD]

Multipurpose Internet Mail Extensions (MIME) ๐Ÿ’Œ An extension to Internet email that lets you transfer non-textual data, such as graphics, audio and fax. See also: Electronic Mail

Multi-User Dungeon (MUD) ๐Ÿ—ก๏ธ Adventure, role playing games, or simulations played on the Internet. Devotees call them "text-based virtual reality adventures," which is so iconic. The games can feature fantasy combat, booby traps and magic. Players interact in real time and can change the "world" in the game as they play it. Most MUDs are based on the Telnet protocol. See also: Telnet. [Source: LAQUEY]

MX Record โ€” See: Mail Exchange Record

NAK โ€” See: Negative Acknowledgment


name resolution ๐Ÿ” The process of mapping a name into its corresponding address. See also: Domain Name System. [Source: RFC1208]

namespace ๐ŸŒท A commonly distributed set of names in which all names are unique. [Source: MALAMUD]

National Institute of Standards and Technology (NIST) ๐Ÿ›๏ธ A United States governmental body that helps out with developing standards. Formerly the National Bureau of Standards. [Source: MALAMUD]

National Research and Education Network (NREN) ๐Ÿš€ The NREN is the realization of an interconnected gigabit computer network devoted to High Performance Computing and Communications. See also: HPPC, IINREN. [Source: HPCC]

National Science Foundation (NSF) ๐Ÿ”ฌ A U.S. government agency whose purpose is to promote the advancement of science. NSF funds science researchers, scientific projects, and infrastructure to improve the quality of scientific research. The NSFNET, funded by NSF, was once an essential part of academic and research communications. It was a highspeed, hierarchical "network of networks." At the highest level, it had a backbone network of nodes, interconnected with T3 (45Mbps) facilities which spanned the continental United States. Attached to that were mid-level networks, and attached to the mid-levels were campus and local networks. See also: backbone network, mid-level network.

Negative Acknowledgment (NAK) ๐Ÿ™… Response to the receipt of either a corrupted or unexpected packet of information. See also: Acknowledgement.

netfind ๐Ÿ•ต๏ธ A research prototype to provide a simple Internet "white pages" user directory. Developed at the University of Colorado, Boulder, it tries to locate telephone and email information given a person's name and a rough description of where the person works. See also: Knowbot, whois, white pages, X.500. [Source: Ryan Moats]

netiquette ๐Ÿซถ A pun on "etiquette" referring to proper behavior on a network. RFC 1855 (FYI 28) contains a netiquette guide produced by the User Services area of the IETF. See also: Acceptable Use Policy, Internet Engineering Task Force.

Netnews โ€” See: Usenet

network ๐Ÿ•ธ๏ธ A computer network is a data communications system that interconnects computer systems at various different sites. A network may be composed of any combination of LANs, MANs or WANs. See also: Local Area Network, Metropolitan Area Network, Wide Area Network, internet.

network address ๐Ÿ  The network portion of an IP address. For a class A network, the network address is the first byte of the IP address. For a class B network, the network address is the first two bytes of the IP address. For a class C network, the network address is the first three bytes of the IP address. In each case, the remainder is the host address. In the Internet, assigned network addresses are globally unique. See also: Internet, IP address, subnet address, host address, Internet Registry.

Network File System (NFS) ๐Ÿ“ A protocol developed by Sun Microsystems, and defined in RFC 1094 (RFC 1813 defines Version 3), that lets a computer system access files over a network as if they were on its local disks. This protocol has been incorporated in products by more than two hundred companies, and it's now a de facto Internet standard. [Source: NNSC]

Network Information Center (NIC) ๐Ÿ“ž A NIC provides information, assistance and services to network users. See also: Network Operations Center.

Network Information Services (NIS) ๐Ÿ’ A set of services, generally provided by a NIC, to help users get around the network. See also: Network Information Center.

Network News Transfer Protocol (NNTP) ๐Ÿ“ฐ A protocol, defined in RFC 977, for the distribution, inquiry, retrieval, and posting of news articles. See also: Usenet.

network mask โ€” See: address mask

network number โ€” See: network address

Network Operations Center (NOC) ๐Ÿ–ฅ๏ธ A location from which the operation of a network or internet is monitored. Additionally, this center usually serves as a clearinghouse for connectivity problems and efforts to resolve those problems. See also: Network Information Center. [Source: NNSC]

Network Time Protocol (NTP) โฐ A protocol that assures accurate local timekeeping with reference to radio and atomic clocks located on the Internet. This protocol is capable of synchronizing distributed clocks within milliseconds over long time periods. See also: Internet. [Source: NNSC]

NFS โ€” See: Network File System

NIC โ€” See: Network Information Center

NIC.DDN.MIL ๐ŸŒ This is the domain name of the DDN NIC. See also: Defense Data Network, Domain Name System, Network Information Center.

NIS โ€” See: Network Information Services

NIST โ€” See: National Institute of Standards and Technology

NNTP โ€” See: Network News Transfer Protocol

NOC โ€” See: Network Operations Center


Nodal Switching System (NSS) ๐Ÿ”€ Main routing nodes in the NSFnet backbone. See also: backbone, National Science Foundation. [Source: MALAMUD]

node ๐Ÿ“ An addressable device attached to a computer network. See also: host, router.

NREN โ€” See: National Research and Education Network

NSF โ€” See: National Science Foundation

NSS โ€” See: Nodal Switching System

NTP โ€” See: Network Time Protocol


OCLC โ€” See: Online Computer Library Catalog

octet ๐Ÿงฎ An octet is 8 bits. This term is used in networking, rather than byte, because some systems have bytes that are not 8 bits long.

Online Computer Library Catalog ๐Ÿ“š OCLC is a nonprofit membership organization offering computer-based services to libraries, educational organizations, and their users. The OCLC library information network connects more than 10,000 libraries worldwide. Libraries use the OCLC System for cataloging, interlibrary loan, collection development, bibliographic verification, and reference searching. [Source: OCLC]

Open Shortest-Path First (OSPF) ๐Ÿ›ฃ๏ธ A link state, as opposed to distance vector, routing protocol. It is an Internet standard IGP defined in RFCs 1583 and 1793. The multicast version, MOSPF, is defined in RFC 1584. See also: Interior Gateway Protocol, Routing Information Protocol.

Open Systems Interconnection (OSI) ๐Ÿงฉ A suite of protocols, designed by ISO committees, to be the international standard computer network architecture. See also: International Organization for Standardization.

OSI โ€” See: Open Systems Interconnection

OSI Reference Model ๐Ÿฐ A seven-layer structure designed to describe computer network architectures and the way that data passes through them. This model was developed by the ISO in 1978 to clearly define the interfaces in multivendor networks, and to provide users of those networks with conceptual guidelines in the construction of such networks. See also: International Organization for Standardization. [Source: NNSC]

OSPF โ€” See: Open Shortest-Path First


packet ๐Ÿ“ฆ The unit of data sent across a network. "Packet" is a generic term used to describe a unit of data at all levels of the protocol stack, but it is most correctly used to describe application data units. See also: datagram, frame.

Packet InterNet Groper (PING) ๐Ÿ“ A program used to test reachability of destinations by sending them an ICMP echo request and waiting for a reply. The term is used as a verb: "Ping host X to see if it is up!" See also: Internet Control Message Protocol. [Source: RFC1208]

Packet Switch Node (PSN) ๐Ÿ” A dedicated computer whose purpose is to accept, route and forward packets in a packet switched network. See also: packet switching, router. [Source: NNSC]

packet switching ๐Ÿ“ฌ A communications paradigm in which packets (messages) are individually routed between hosts, with no previously established communication path. See also: circuit switching, connection-oriented, connectionless.

PD โ€” Public Domain

PDU โ€” See: Protocol Data Unit

PEM โ€” See: Privacy Enhanced Mail

PGP โ€” See: Pretty Good Privacy

PING โ€” See: Packet INternet Groper


Point Of Presence (POP) ๐Ÿ“ A site where there exists a collection of telecommunications equipment, usually digital leased lines and multi-protocol routers.

Point-to-Point Protocol (PPP) ๐Ÿ”Œ The Point-to-Point Protocol, defined in RFC 1661, provides a method for transmitting packets over serial point-to-point links. There are many other RFCs which define extensions to the basic protocol. See also: Serial Line IP. [Source: FYI4]

POP โ€” See: Post Office Protocol and Point Of Presence

port ๐Ÿšช A port is a transport layer demultiplexing value. Each application has a unique port number associated with it. See also: Transmission Control Protocol, User Datagram Protocol.

Post Office Protocol (POP) ๐Ÿ“จ A protocol designed to allow single user hosts to read electronic mail from a server. Version 3, the most recent and most widely used, is defined in RFC 1725. See also: Electronic Mail.

Postal Telegraph and Telephone (PTT) โ˜Ž๏ธ Outside the USA, PTT refers to a telephone service provider, which is usually a monopoly, in a particular country.

postmaster ๐Ÿ’Œ Okay bestie, the postmaster is the person at a site who handles email problems, answers questions about users, and does all the related work. Literally the hero of the inbox ๐Ÿฆธโ€โ™€๏ธ See also: Electronic Mail. [Source: ZEN]

PPP ๐ŸŽ€ See: Point-to-Point Protocol

Pretty Good Privacy (PGP) ๐Ÿ” A program developed by Phil Zimmerman that cryptographically protects files and electronic mail from being read by others. It can also be used to digitally sign a document or message, which authenticates the creator. Very trustworthy energy โœจ See also: encryption, Data Encryption Standard, RSA.

Privacy Enhanced Mail (PEM) ๐Ÿ•ต๏ธโ€โ™€๏ธ Internet email that gives you confidentiality, authentication and message integrity using various encryption methods. See also: Electronic Mail, encryption.

Prospero ๐Ÿงš A distributed filesystem that gives you the power to create multiple views of a single collection of files spread across the Internet. Prospero provides a file naming system, and file access happens through existing access methods (e.g. anonymous FTP and NFS). The Prospero protocol is also used for communication between clients and servers in the archie system. See also: anonymous FTP, archie, archive site, Gopher, Network File System, Wide Area Information Servers.

protocol ๐Ÿ“œ A formal description of message formats and the rules two computers must follow to exchange those messages. Protocols can describe low-level details of machine-to-machine interfaces (e.g., the order in which bits and bytes are sent across a wire) or high-level exchanges between allocation programs (e.g., the way in which two programs transfer a file across the Internet). [Source: MALAMUD]

protocol converter ๐Ÿ”„ A device or program that translates between different protocols which serve similar functions (e.g. TCP and TP4).

Protocol Data Unit (PDU) ๐Ÿ“ฆ "PDU" is internationalstandardscomitteespeak for packet. See also: packet.

protocol stack ๐Ÿฅž A layered set of protocols which work together to provide a set of network functions. See also: layer, protocol.

proxy ARP ๐Ÿซฅ The technique in which one machine, usually a router, answers ARP requests intended for another machine. By "faking" its identity, the router accepts responsibility for routing packets to the "real" destination. Proxy ARP allows a site to use a single IP address with two physical networks. Subnetting would normally be a better solution. See also: Address Resolution Protocol [Source: RFC1208]

PSN ๐Ÿ›ฐ๏ธ See: Packet Switch Node.

PTT ๐Ÿ“ž See: Postal, Telegraph and Telephone

queue ๐Ÿซถ A backup of packets awaiting processing.

RARE ๐ŸŒ Reseaux Associes pour la Recherche Europeenne. See: Trans-European Research and Education Networking Association.

RARP ๐Ÿ” See: Reverse Address Resolution Protocol

RBOC ๐Ÿข Regional Bell Operating Company

Read The F*cking Manual (RTFM) ๐Ÿ™ˆ This acronym is often used when someone asks a simple or common question.

Read The Source Code (RTSC) ๐Ÿ‘ฉโ€๐Ÿ’ป This acronym is often used when a software developer asks a question about undocumented code.

reassembly ๐Ÿงฉ The IP process in which a previously fragmented packet is reassembled before being passed to the transport layer. See also: fragmentation.

recursive ๐Ÿ”‚ See: recursive

regional ๐Ÿ—บ๏ธ See: mid-level network

remote login ๐Ÿ–ฅ๏ธ Operating on a remote computer, using a protocol over a computer network, as though locally attached. See also: Telnet.

Remote Procedure Call (RPC) ๐Ÿ“žโœจ An easy and popular paradigm for implementing the client-server model of distributed computing. In general, a request is sent to a remote system to execute a designated procedure, using arguments supplied, and the result is returned to the caller. There are many variations and subtleties in various implementations, resulting in a variety of different (incompatible) RPC protocols. [Source: RFC1208]

repeater ๐Ÿ“ก A device which propagates electrical signals from one cable to another. See also: bridge, gateway, router.

Request For Comments (RFC) ๐Ÿ“๐Ÿ’œ The document series, begun in 1969, which describes the Internet suite of protocols and related experiments. Not all (in fact very few) RFCs describe Internet standards, but all Internet standards are written up as RFCs. The RFC series is unusual in that the proposed protocols are forwarded by the Internet research and development community, acting on their own behalf, as opposed to the formally reviewed and standardized protocols that are promoted by organizations such as CCITT and ANSI. See also: BCP, FYI, STD.

Reseaux IP Europeens (RIPE) ๐Ÿ‡ช๐Ÿ‡บ A collaboration between European networks which use the TCP/IP protocol suite.

Reverse Address Resolution Protocol (RARP) ๐Ÿ”„ A protocol, defined in RFC 903, which provides the reverse function of ARP. RARP maps a hardware (MAC) address to an internet address. It is used primarily by diskless nodes when they first initialize to find their internet address. See also: Address Resolution Protocol, BOOTP, internet address, MAC address.

RFC ๐Ÿ“ See: Request For Comments

RFC 822 ๐Ÿ’Œ The Internet standard format for electronic mail message headers. Mail experts often refer to "822 messages." The name comes from RFC 822, which contains the specification. 822 format was previously known as 733 format. See also: Electronic Mail. [Source: COMER]

RIP ๐Ÿ›ฃ๏ธ See: Routing Information Protocol

RIPE ๐Ÿ‡ช๐Ÿ‡บ See: Reseaux IP Europeenne

Round-Trip Time (RTT) โฑ๏ธ A measure of the current delay on a network. [Source: MALAMUD]

route ๐Ÿ›ค๏ธ The path that network traffic takes from its source to its destination. Also, a possible path from a given host to another host or destination.

routed ๐Ÿ›ฃ๏ธ Route Daemon. A program which runs under 4.2BSD/4.3BSD UNIX systems (and derived operating systems) to propagate routes among machines on a local area network, using the RIP protocol. Pronounced "route-dee". See also: Routing Information Protocol, gated.

router ๐Ÿ”€ A device which forwards traffic between networks. The forwarding decision is based on network layer information and routing tables, often constructed by routing protocols. See also: bridge, gateway, Exterior Gateway Protocol, Interior Gateway Protocol.

routing ๐Ÿงญ The process of selecting the correct interface and next hop for a packet being forwarded. See also: hop, router, Exterior Gateway Protocol, Interior Gateway Protocol.

routing domain ๐Ÿฐ A set of routers exchanging routing information within an administrative domain. See also: Administrative Domain, router.

Routing Information Protocol (RIP) ๐Ÿ›ฃ๏ธ A distance vector, as opposed to link state, routing protocol. It is an Internet standard IGP defined in RFC 1058. See also: Interior Gateway Protocol, Open Shortest-Path First.

RPC ๐Ÿ“ž See: Remote Procedure Call

RSA ๐Ÿ”‘ A public-key cryptographic system which may be used for encryption and authentication. It was invented in 1977 and named for its inventors: Ron Rivest, Adi Shamir, and Leonard Adleman. See also: encryption, Data Encryption Standard, Pretty Good Privacy.

RTFM ๐Ÿ™ˆ See: Read The F*cking Manual

RTSC ๐Ÿ‘ฉโ€๐Ÿ’ป See: Read The Source Code

RTT โฑ๏ธ See: Round-Trip Time

SDH ๐Ÿ“ถ See: Synchronous Digital Hierarchy

Serial Line IP (SLIP) ๐Ÿ”Œ A protocol used to run IP over serial lines, such as telephone circuits or RS-232 cables, interconnecting two systems. SLIP is defined in RFC 1055, but is not an Internet Standard. It is being replaced by PPP. See also: Point-to-Point Protocol.

server ๐Ÿ–ง A provider of resources (e.g. file servers and name servers). See also: client, Domain Name System, Network File System.

SGML ๐Ÿท๏ธ See: Standardized Generalized Markup Language

SIG ๐Ÿซ‚ Special Interest Group

signature โœ๏ธ The three or four line message at the bottom of a piece of email or a Usenet article which identifies the sender. Large signatures (over five lines) are generally frowned upon. See also: Electronic Mail, Usenet.

Simple Mail Transfer Protocol (SMTP) ๐Ÿ“ฌ A protocol used to transfer electronic mail between computers. It is specified in RFC 821, with extensions specified in many other RFCs. It is a server to server protocol, so other protocols are used to access the messages. See also: Electronic Mail, Post Office Protocol, RFC 822.

Simple Network Management Protocol (SNMP) ๐Ÿงƒ The Internet standard protocol developed to manage nodes on an IP network. The first version is defined in RFC 1157 (STD 15). SNMPv2 (version 2) is defined in too many RFCs to list. It is currently possible to manage wiring hubs, toasters, jukeboxes, etc. See also: Management Information Base.

SLIP ๐Ÿ”Œ See: Serial Line IP

SMDS ๐Ÿ“ถ See: Switched Multimegabit Data Service

SMI ๐Ÿงฑ See: Structure of Management Information

SMTP ๐Ÿ“ฌ See: Simple Mail Transfer Protocol

SNA ๐Ÿ›๏ธ See: Systems Network Architecture

snail mail ๐ŸŒ A pejorative term referring to the U.S. postal service.

SNMP ๐Ÿงƒ See: Simple Network Management Protocol

SONET ๐Ÿ“ถ See: Synchronous Optical NETwork

Standardized Generalized Markup Language (SGML) ๐Ÿท๏ธ An international standard for the definition of system-independent, device-independent methods of representing text in electronic form. See also: Hypertext Markup Language.

STD ๐Ÿ“š A subseries of RFCs that specify Internet standards. The official list of Internet standards is in STD 1. See also: Request For Comments.

stream-oriented ๐ŸŒŠ A type of transport service that allows its client to send data in a continuous stream. The transport service will guarantee that all data will be delivered to the other end in the same order as sent and without duplicates. See also: Transmission Control Protocol. [Source: MALAMUD]

Structure of Management Information (SMI) ๐Ÿงฑ The rules used to define the objects that can be accessed via a network management protocol. These rules are defined in RFC 1155 (STD 17). The acronym is pronounced "Ess Em Eye." See also: Management Information Base. .br [Source: RFC1208]

stub network ๐ŸŒฟ A stub network only carries packets to and from local hosts. Even if it has paths to more than one other network, it does not carry traffic for other networks. See also: backbone, transit network.

subnet ๐Ÿง A portion of a network, which may be a physically independent network segment, which shares a network address with other portions of the network and is distinguished by a subnet number. A subnet is to a network what a network is to an internet. See also: internet, network. [Source: FYI4]

subnet address ๐ŸŽ€ The subnet portion of an IP address. In a subnetted network, the host portion of an IP address is split into a subnet portion and a host portion using an address (subnet) mask. See also: address mask, IP address, network address, host address.

subnet mask ๐ŸŽ€ See: address mask

subnet number ๐ŸŽ€ See: subnet address

supernet โœจ Okay so a supernet is when you take a bunch of IP network addresses and advertise them as ONE classless network address, bestie ๐Ÿซถ Picture four Class C networks: 192.0.8.0, 192.0.9.0, 192.0.10.0 and 192.0.11.0, each with the intrinsic network mask of 255.255.255.0. You can advertise 192.0.8.0 with a subnet mask of 255.255.252.0 and suddenly they're one aggregate ๐Ÿ’… It's giving efficiency. See also: IP address, network address, network mask, Classless Inter-domain Routing.

Switched Multimegabit Data Service (SMDS) ๐Ÿฆ‹ An emerging high-speed, datagram-based public data network service developed by Bellcore, and it's expected to be widely used by telephone companies as the basis for their data networks. Main character energy for telcos ๐ŸŽ€ See also: Metropolitan Area Network. [Source: RFC1208]

Synchronous Digital Hierarchy (SDH) ๐ŸŒˆ The European standard for high-speed data communications over fiber-optic media. Transmission rates range from 155.52Mbps to 2.5Gbps โœจ

Synchronous Optical NETwork (SONET) ๐ŸŒธ SONET is an international standard for high-speed data communications over fiber-optic media, no cap, it's iconic. The transmission rates range from 51.84Mbps to 2.5Gbps.

Systems Network Architecture (SNA) ๐Ÿ‘‘ A proprietary networking architecture used by IBM and IBM-compatible mainframe computers. [Source: NNSC]

T1 ๐Ÿ“ A term for a digital carrier facility used to transmit a DS-1 formatted digital signal at 1.544 megabits per second.

T3 ๐Ÿ’œ A term for a digital carrier facility used to transmit a DS-3 formatted digital signal at 44.746 megabits per second. [Source: FYI4]

TAC ๐Ÿ™ˆ See: Terminal Access Controller (TAC)

talk ๐Ÿ’ฌ A protocol which allows two people on remote computers to communicate in a real-time fashion. See also: Internet Relay Chat.

TCP ๐Ÿฆ‹ See: Transmission Control Protocol

TCP/IP Protocol Suite ๐ŸŒˆ Transmission Control Protocol over Internet Protocol. This is a common shorthand which refers to the suite of transport and application protocols which runs over IP. It's the whole squad! See also: IP, ICMP, TCP, UDP, FTP, Telnet, SMTP, SNMP.

TELENET ๐Ÿงš The original name for what is now SprintNet. It should not be confused with the Telnet protocol or application program. Same spelling-ish, totally different vibes, so don't mix them up ๐Ÿ™…

Telnet ๐Ÿ’ป Telnet is the Internet standard protocol for remote terminal connection service. It is defined in RFC 854 and extended with options by many other RFCs.

TERENA ๐ŸŒ See: Trans-European Research and Education Networking Association

Terminal Access Controller (TAC) ๐ŸŒธ A device which was once used to connect terminals to the Internet, usually using dialup modem connections and the TACACS protocol. While the device is no longer in use, TACACS+ is a protocol in current use. Retired icon, but the protocol is still slaying ๐Ÿ’…

terminal emulator ๐Ÿ’… A program that allows a computer to emulate a terminal. The workstation thus appears as a terminal to the remote host. [Source: MALAMUD]

terminal server ๐ŸŽ€ A device which connects many terminals to a LAN through one network connection. A terminal server can also connect many network users to its asynchronous ports for dial-out capabilities and printer access. See also: Local Area Network.

Three Letter Acronym (TLA) ๐Ÿ”ฅ A tribute to the use of acronyms in the computer field. See also: Extended Four Letter Acronym. The irony of a three-letter acronym for "three letter acronym" is not lost on me ๐Ÿ’€

Time to Live (TTL) โณ A field in the IP header which indicates how long this packet should be allowed to survive before being discarded. It is primarily used as a hop count. See also: Internet Protocol. [Source: MALAMUD]

TLA ๐Ÿ™ƒ See: Three Letter Acronym

TN3270 ๐Ÿ–ฅ๏ธ A variant of the Telnet program that allows one to attach to IBM mainframes and use the mainframe as if you had a 3270 or similar terminal. [Source: BIG-LAN]

token ring ๐Ÿ’ A token ring is a type of LAN with nodes wired into a ring. Each node constantly passes a control message (token) on to the next; whichever node has the token can send a message. Often, "Token Ring" is used to refer to the IEEE 802.5 token ring standard, which is the most common type of token ring. See also: 802.x, Local Area Network.

topology ๐Ÿ—บ๏ธ A network topology shows the computers and the links between them. A network layer must stay abreast of the current network topology to be able to route packets to their final destination. [Source: MALAMUD]

traceroute ๐Ÿ•ต๏ธ A program available on many systems which traces the path a packet takes to a destination. It is mostly used to debug routing problems between hosts. There is also a traceroute protocol defined in RFC 1393.

Trans-European Research and Education Networking Association (TERENA) ๐ŸŒ TERENA was formed in October 1994 by the merger of RARE and EARN to promote and participate in the development of a high quality international information and telecommunications infrastructure for the benefit of research and education. See also: Reseaux Associes pour la Recherche Europeenne, European Academic and Research Network. [Source: TERENA Statutes]

transceiver ๐Ÿ“ก Transmitter-receiver. The physical device that connects a host interface to a local area network, such as Ethernet. Ethernet transceivers contain electronics that apply signals to the cable and sense collisions. [Source: RFC1208]

transit network ๐Ÿš‰ A transit network passes traffic between networks in addition to carrying traffic for its own hosts. It must have paths to at least two other networks. See also: backbone, stub network.

Transmission Control Protocol (TCP) ๐Ÿฆ‹ An Internet Standard transport layer protocol defined in RFC 793. It is connection-oriented and stream-oriented, as opposed to UDP. See also: connection-oriented, stream-oriented, User Datagram Protocol.

Trojan Horse ๐Ÿด A computer program which carries within itself a means to allow the creator of the program access to the system using it. See also: virus, worm. Bestie, don't accept gifts from strangers ๐Ÿ’€

TTFN ๐Ÿ‘‹ Ta-Ta For Now

TTL ๐Ÿ™ƒ See: Time to Live

tunnelling ๐Ÿš‡ Tunnelling refers to encapsulation of protocol A within protocol B, such that A treats B as though it were a datalink layer. Tunnelling is used to get data between administrative domains which use a protocol that is not supported by the internet connecting those domains. See also: Administrative Domain.

twisted pair ๐Ÿงต A type of cable in which pairs of conductors are twisted together to produce certain electrical properties.

UDP ๐ŸŒŠ See: User Datagram Protocol

unicast ๐ŸŽฏ An address which only one host will recognize. See also: broadcast, multicast.

Uniform Resource Locators (URL) ๐Ÿ”— A URL is a compact (most of the time) string representation for a resource available on the Internet. URLs are primarily used to retrieve information using WWW. The syntax and semantics for URLs are defined in RFC 1738. See also: World Wide Web.

Universal Time Coordinated (UTC) ๐Ÿ•ฐ๏ธ This is Greenwich Mean Time. [Source: MALAMUD]

UNIX-to-UNIX CoPy (UUCP) ๐Ÿ“ฌ This was initially a program run under the UNIX operating system that allowed one UNIX system to send files to another UNIX system via dial-up phone lines. Today, the term is more commonly used to describe the large international network which uses the UUCP protocol to pass news and electronic mail. See also: Electronic Mail, Usenet.

urban legend ๐Ÿ‘ป A story, which may have started with a grain of truth, that has been embroidered and retold until it has passed into the realm of myth. It is an interesting phenomenon that these stories get spread so far, so fast and so often. Urban legends never die, they just end up on the Internet! Some legends that periodically make their rounds include "The Infamous Modem Tax," "Craig Shergold/Brain Tumor/Get Well Cards," and "The $250 Cookie Recipe." [Source: LAQUEY]

URL ๐Ÿ”— See: Uniform Resource Locators

Usenet ๐Ÿ—ž๏ธ A collection of thousands of topically named newsgroups, the computers which run the protocols, and the people who read and submit Usenet news. Not all Internet hosts subscribe to Usenet and not all Usenet hosts are on the Internet. See also: Network News Transfer Protocol, UNIX-to-UNIX CoPy. [Source: NWNET]

User Datagram Protocol (UDP) ๐ŸŒŠ An Internet Standard transport layer protocol defined in RFC 768. It is a connectionless protocol which adds a level of reliability and multiplexing to IP. See also: connectionless, Transmission Control Protocol.

UTC ๐Ÿ•ฐ๏ธ See: Universal Time Coordinated

UUCP ๐Ÿ“ฌ See: UNIX-to-UNIX CoPy

uudecode ๐Ÿ”“ A program which reverses the effect of uuencode. See also: uuencode.

uuencode ๐Ÿ” A program which reversibly converts a binary file in ASCII. It is used to send binary files via email, which generally does not allow (or garbles) the transmission of binary information. The original binary can be restored with uudecode. The encoding process generally creates an ASCII file larger than the original binary, so compressing the binary before running uuencode is highly recommended.

Veronica ๐Ÿ” A Gopher utility which effectively searches Gopher servers based on a user's list of keywords. The name was chosen to be a "mate" to another utility named "Archie." It later became an acronym for Very Easy Rodent Oriented Netwide Index to Computer Archives. See also: archie, Gopher.

virtual circuit ๐Ÿ›ค๏ธ A network service which provides connection-oriented service without necessarily doing circuit-switching. See also: connection-oriented.

virus ๐Ÿฆ  A program which replicates itself on computer systems by incorporating itself into other programs which are shared among computer systems. See also: Trojan Horse, worm.

W3 ๐Ÿ•ธ๏ธ See: World Wide Web

WAIS ๐Ÿ”Ž See: Wide Area Information Servers

WAN ๐ŸŒ See: Wide area network

WebCrawler ๐Ÿ•ท๏ธ A WWW search engine. The aim of the WebCrawler Project is to provide a high-quality, fast, and free Internet search service. The WebCrawler may be reached at "http://webcrawler.com/". [Source: WebCrawler's "WebCrawler Facts"]

WG ๐Ÿง‘โ€๐Ÿคโ€๐Ÿง‘ See: Working Group

white pages ๐Ÿ“– The Internet supports several databases that contain basic information about users, such as e-mail addresses, telephone numbers, and postal addresses. These databases can be searched to get information about particular individuals. Because they serve a function akin to the telephone book, these databases are often referred to as "white pages." See also: Knowbot, netfind, whois, X.500, InterNIC.

whois ๐Ÿ”Ž An Internet program which allows users to query a database of people and other Internet entities, such as domains, networks, and hosts. The primary database is kept at the InterNIC. The information stored includes a person's company name, address, phone number and email address. The latest version of the protocol, WHOIS++, is defined in RFCs 1834 and 1835. See also: InterNIC, white pages, Knowbot, netfind, X.500. Now you know who's who on the Internet ๐Ÿ’œ

Wide Area Information Servers (WAIS) Okay so WAIS is a distributed information service ๐Ÿ” that gives you simple natural language input, indexed searching for fast retrieval, and a "relevance feedback" mechanism which allows the results of initial searches to influence future searches. It's giving smart search energy โœจ Public domain implementations are available. See also: archie, Gopher, Prospero.

Wide Area Network (WAN) A network, usually constructed with serial lines ๐Ÿงต, which covers a large geographic area ๐ŸŒ. See also: Local Area Network, Metropolitan Area Network.

Working Group (WG) A working group, within the IETF ๐ŸŽ€, is a group of people who work under a charter to achieve a certain goal. That goal may be the creation of an Informational document, the creation of a protocol specification, or the resolution of problems in the Internet. Most working groups have a finite lifetime. That is, once a working group has achieved its goal, it disbands ๐Ÿ‘‹ There is no official membership for a working group. Unofficially, a working group member is somebody who is on that working group's mailing list ๐Ÿ“ฌ; however, anyone may attend a working group meeting. See also: Internet Engineering Task Force, Birds Of a Feather.

World Wide Web (WWW, W3) A hypertext-based, distributed information system created by researchers at CERN in Switzerland ๐ŸŒ Users may create, edit or browse hypertext documents. The clients and servers are freely available ๐ŸŒธ

worm A computer program which replicates itself and is self-propagating ๐Ÿ› Worms, as opposed to viruses, are meant to spawn in network environments. Network worms were first defined by Shoch & Hupp of Xerox in ACM Communications (March 1982). The Internet worm of November 1988 is perhaps the most famous; it successfully propagated itself on over 6,000 systems across the Internet ๐Ÿ˜ญ See also: Trojan Horse, virus.

WRT With Respect To

WWW See: World Wide Web

WYSIWYG What You See is What You Get

X X is the name for TCP/IP based network-oriented window systems. Network window systems allow a program to use a display on a different computer. The most widely-implemented window system is X11 - a component of MIT's Project Athena. ๐ŸชŸ

X.25 A data communications interface specification developed to describe how data passes into and out of public data communications networks. The CCITT and ISO approved protocol suite defines protocol layers 1 through 3.

X.400 The CCITT and ISO standard for electronic mail. It is widely used in Europe and Canada. ๐Ÿ’Œ

X.500 The CCITT and ISO standard for electronic directory services. See also: white pages, Knowbot, whois.

XDR See: eXternal Data Representation

Xerox Network System (XNS) A protocol suite developed by Xerox Corporation to run on LAN and WAN networks, where the LANs are typically Ethernet. Implementations exist for both Xerox's workstations and 4.3BSD, and 4.3BSD-derived, systems. XNS denotes not only the protocol stack, but also an architecture of standard programming interfaces, conventions, and service functions for authentication, directory, filing, email, and remote procedure call. XNS is also the name of Xerox's implementation. See also: Ethernet, Berkeley Software Distribution, Local Area Network, Wide Area Network. [Source: Jeff Hodges]

XNS See: Xerox Network System

Yahoo! Yahoo! is a hierarchical subject-oriented guide for the World Wide Web and Internet. Yahoo! lists sites and categorizes them into appropriate subject categories. Yahoo! may be reached at "http://www.yahoo.com/". [Source: Yahoo's "What is Yahoo?"] ๐Ÿงš

Yellow Pages (YP) A historic (i.e., no longer in use) service used by UNIX administrators to manage databases distributed across a network. ๐Ÿ“’

YP See: Yellow Pages

zone A logical group of network devices. ๐Ÿฆ‹


References ๐Ÿ“š

  • BIG-LAN "BIG-LAN Frequently Asked Questions Memo", BIG-LAN DIGEST V4:I8, February 14, 1992.
  • COMER Comer, Douglas, "Internetworking with TCP/IP: Principles, Protocols and Architecture", Prentice Hall, Englewood Cliffs, NJ, 1991.
  • FYI4 Malkin, G., A. Marine, "FYI on Questions and Answers: Answers to Commonly asked "New Internet User" Questions", RFC 1325 (FYI 4), Xylogics, SRI, May 1992.
  • HACKER "THIS IS THE JARGON FILE", Version 2.9.8, January 1992.
  • HPCC "Grand Challenges 1993: High Performance Computing and Communications", Committee on Physical, Mathmatical and Engineering Sciences of the Federal Coordinating Council for Science, Engineering and Technology.
  • MALAMUD Malamud, Carl, "Analyzing Sun Networks", Van Nostrand Reinhold, New York, NY, 1992.
  • NNSC "NNSC's Hypercard Tour of the Internet".
  • LAQUEY LaQuey, Tracy, with Jeanne C. Ryer, "The Internet Companion: A Beginner's Guide to Global Networking", Addison-Wesley, Reading, MA, 1992.
  • NWNET Kochmer, Jonathan, and NorthWestNet, "The Internet Passport: NorthWestNets Guide to Our World Online", NorthWestNet, Bellevue, WA, 1992.
  • RFC1208 Jacobsen, O., D. Lynch, "A Glossary of Networking Terms", RFC 1208, Interop, Inc., March 1991.
  • STD1 Postel, J., "INTERNET OFFICIAL PROTOCOL STANDARDS", RFC 1920 (STD 1), March 1996.
  • STD2 Reynolds, J., J. Postel, "ASSIGNED NUMBERS", RFC 1700 (STD 2), ISI, October 1994.
  • TAN Tanenbaum, Andrew S., "Computer Networks; 2nd ed.", Prentice Hall, Englewood Cliffs, NJ, 1989.
  • ZEN Kehoe, Brendan P., "Zen and the Art of the Internet", February 1992.

Security Considerations ๐Ÿ”

Okay, this one's serious bestie ๐Ÿฅบ While security is not explicitly discussed in this document, some of the glossary's entries are security related. See the entries for Access Control List (ACL), authentication, Computer Emergency Response Team (CERT), cracker, Data Encryption Key (DEK), Data Encryption Standard (DES), encryption, Kerberos, Message Digest (MD-2, MD-4, MD-5), Pretty Good Privacy (PGP), Privacy Enhanced Mail (PEM), RSA, Trojan Horse, virus, and worm.


Editor's Address ๐Ÿ’Œ

Gary Scott Malkin
Xylogics/Bay Networks
53 Third Avenue
Burlington, MA 01803

Phone:  (617) 238-6237
EMail:  gmalkin@Xylogics.COM
๐Ÿ“ฆ where this page comes from