RFC1983 - Internet Users Glossary

Network Working Group G. Malkin, Editor
Request for Comments: 1983 Xylogics
FYI: 18 August 1996
Obsoletes: 1392
Category: Informational
Internet Users" Glossary
Status of this Memo
This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of
this memo is unlimited.
Abstract
There are many networking glossaries in existence. This glossary
concentrates on terms which are specific to the Internet. Naturally,
there are entries for some basic terms and acronyms because other
entries refer to them.
Acknowledgements
This document is the work of the User Glossary Working Group of the
User Services Area of the Internet Engineering Task Force. I would
especially like to thank Ryan Moats/InterNIC for his careful review
and many contributions to this document.
Table of Contents
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
10Base2
A physical layer communications specification for 10Mbps, baseband
data transmission over a coaxial cable (Thinnet) with a maximum
cable segment length of 200 meters.
10Base5
A physical layer communications specification for 10Mbps, baseband
data transmission over a coaxial cable (Thicknet) with a maximum
cable segment length of 500 meters.
10BaseF
A physical layer communications specification for 10Mbps, baseband
data transmission over a fiber-optic cable.
10BaseT
A physical layer communications specification for 10Mbps, baseband
data transmission over a twisted-pair copper wire.
802.x
The set of IEEE standards for the definition of LAN protocols.
See also: IEEE.
822
See: RFC822
:-)
This odd symbol is one of the ways a person can portray "mood" in
the very flat medium of computers--by using "smiley faces". This
is "metacommunication", and there are literally hundreds of sUCh
symbols, from the obvious to the obscure. This particular example
eXPresses "happiness". Don"t see it? Tilt your head to the left
90 degrees. Smiles are also used to denote sarcasm.
[Source: ZEN]
abstract syntax
A description of a data structure that is independent of machine-
oriented structures and encodings.
[Source: RFC1208]
Abstract Syntax Notation One (ASN.1)
The language used by the OSI protocols for describing abstract
syntax. This language is 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)
Many transit networks have policies which restrict the use to
which the network may be put. For example, some networks may only
be used for non-commercial purposes. Some AUPs limit the type of
material which can be made available to the public (e.g.,
pornographic material). Enforcement of AUPs varies with the
network. See also: netiquette.
Access Control List (ACL)
Most network security systems operate by allowing selective use of
services. An Access Control List is the usual means by which
access to, and denial of, services is controlled. It is simply a
list of the services available, each with a list of the hosts
permitted to use the service.
ACK
See: Acknowledgment
acknowledgment (ACK)
A type of message sent to indicate that a block of data arrived at
its destination without error. See also: Negative
Acknowledgement.
[Source: NNSC]
ACL
See: Access Control List
AD
See: Administrative Domain
address
There are four types of addresses in common use within the
Internet. 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 used to identify which bits in an IP address correspond
to the network and subnet portions of the address. This mask is
often referred to as the subnet mask because the network portion
of the address (i.e., the network mask) can be determined by the
encoding inherent in an IP address. See also: Classless Inter-
domain Routing.
address resolution
Conversion of a network-layer address (e.g. IP address) into the
corresponding physical address (e.g., MAC address). See also: IP
address, MAC address.
Address Resolution Protocol (ARP)
Used to dynamically discover the low level physical network
hardware address that corresponds to the high level IP address for
a given host. ARP is limited to physical network systems that
support broadcast packets that can be heard by all hosts on the
network. See also: proxy ARP, Reverse Address Resolution
Protocol.
Administrative Domain (AD)
A collection of hosts and routers, and the interconnecting
network(s), managed by a single administrative authority.
Advanced Research Projects Agency (ARPA)
An agency of the U.S. Department of Defense responsible for the
development of new technology for use by the military. ARPA
(formerly known as DARPA, nee ARPA) was responsible for funding
much of the development of the Internet we know today, including
the Berkeley version of Unix and TCP/IP.
[Source: NNSC]
Advanced Research Projects Agency Network (ARPANET)
A pioneering longhaul network funded by ARPA. Now retired, it
served as the basis for early networking research as well as a
central backbone during the development of the Internet. The
ARPANET consisted of individual packet switching computers
interconnected by leased lines. See also: Advanced Research
Projects Agency.
[Source: FYI4]
agent
In the client-server model, the part of the system that performs
information preparation and exchange on behalf of a client or
server application.
[Source: RFC1208]
alias
A name, usually short and easy to remember, that is translated
into another name, usually long and difficult to remember.
American National Standards Institute (ANSI)
This organization is responsible for approving U.S. standards in
many areas, including computers and communications. Standards
approved by this organization are often called ANSI standards
(e.g., ANSI C is the version of the C language approved by ANSI).
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 widely used in the
computer industry. See also: EBCDIC.
anonymous FTP
Anonymous FTP allows a user to retrieve documents, files,
programs, and other archived data from anywhere in the Internet
without having to establish a userid and passWord. By using the
special userid of "anonymous" the network user will bypass local
security checks and will have access to publicly accessible files
on the remote system. 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 developed by Apple Computer for
communication between Apple Computer products and other computers.
This protocol is independent of the network layer on which it is
run. 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 performs a function directly for a user. FTP, mail
and Telnet clients are examples of network applications.
application layer
The top layer of the network protocol stack. The application
layer is concerned with the semantics of work (e.g. formatting
electronic mail messages). How to represent that data and how to
reach the foreign node are issues for lower layers of the network.
[Source: MALAMUD]
Application Program Interface (API)
A set of calling conventions which define how a service is invoked
through a software package.
[Source: RFC1208]
archie
A system to automatically gather, index and serve information on
the Internet. The initial implementation of archie provided 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 provides access to a collection of files across the
Internet. For example, an anonymous FTP archive site provides
access to arcived material via the FTP protocol. WWW servers can
also serve as 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
The RFC[STD2] which documents the currently assigned values from
several series of numbers used in network protocol
implementations. This RFCis updated periodically and, in any
case, current information can be oBTained from the Internet
Assigned Numbers Authority (IANA). If you are developing a
protocol or application that will require the use of a link,
socket, port, protocol, etc., please contact the IANA to receive a
number assignment. See also: Internet Assigned Numbers Authority,
STD.
[Source: STD2]
Asynchronous Transfer Mode (ATM)
A standard which defines high-load, high-speed (1.544Mbps through
1.2Gbps), fixed-size packet (cell) switching with dynamic
bandwidth allocation. ATM is also known as "fast packet."
ATM
See: Asynchronous Transfer Mode
AUP
See: Acceptable Use Policy
authentication
The verification of the identity of a person or process.
[Source: MALAMUD]
Autonomous System (AS)
A collection of routers under a single administrative authority
using a common Interior Gateway Protocol for routing packets.
backbone
The top level in a hierarchical network. Stub and transit
networks which connect to the same backbone are guaranteed to be
interconnected. See also: stub network, transit network.
bandwidth
Technically, the difference, in Hertz (Hz), between the highest
and lowest frequencies of a transmission channel. However, as
typically used, the amount of data that can be sent through a
given communications circuit.
bang path
A series of machine names used to direct electronic mail from one
user to another, typically by specifying an explicit UUCP path
through which the mail is to be routed. See also: email address,
mail path, UNIX-to-UNIX CoPy.
baseband
A transmission medium through which digital signals are sent
without complicated frequency shifting. In general, only one
communication channel is available at any given time. Ethernet is
an example of a baseband network. See also: broadband, Ethernet.
[Source: NNSC]
Basic Encoding Rules (BER)
Standard rules for encoding data units described in ASN.1.
Sometimes incorrectly lumped under the term ASN.1, which properly
refers only to the abstract syntax description language, not the
encoding technique. See also: Abstract Syntax Notation One.
[Source: NNSC]
BBS
See: Bulletin Board System
BCNU
Be Seein" You
BCP
The newest subseries of RFCs which are written to describe Best
Current Practices in the Internet. Rather than specifying a
protocol, these documents specify the best ways to use the
protocols and the best ways to configure options to ensure
interoperability between various vendors" products. BCPs carry
the endorsement of the IESG. See also: Request For Comments,
Internet Engineering Steering Group.
BER
See: Basic Encoding Rules
Berkeley Internet Name Daemon (BIND)
Implementation of a DNS server developed and distributed by the
University of California at Berkeley. Many Internet hosts run
BIND, and it is the ancestor of many commercial BIND
implementations. See also: Domain Name System.
Berkeley Software Distribution (BSD)
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, e.g., "4.3 BSD" is version 4.3 of the Berkeley UNIX
distribution. Many Internet hosts run BSD software, and it is the
ancestor of many commercial UNIX implementations.
[Source: NNSC]
BGP
See: Border Gateway Protocol
big-endian
A format for storage or transmission of 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.
See also: little-endian.
[Source: RFC1208]
binary
11001001
BIND
See: Berkeley Internet Name Daemon
Birds Of a Feather (BOF)
A Birds Of a Feather (flocking together) is an informal discussion
group. It is formed, often ad hoc, to consider a specific issue
and, therefore, has a narrow focus. See also: Working Group.
Bitnet
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.
BOF
See: Birds Of a Feather
BOOTP
The Bootstrap Protocol, described in RFC1542, is used for booting
diskless nodes. See also: Dynamic Host Configuration Protocol,
Reverse Address Resolution Protocol.
Border Gateway Protocol (BGP)
The Border Gateway Protocol is an exterior gateway protocol
defined in RFC1771. It"s design is based on experience gained
with EGP, as defined in RFC904, and EGP usage in the NSFNET
Backbone, as described in RFCs 1092 and 1093. See also: Exterior
Gateway Protocol.
bounce
The return of a piece of mail because of an error in its delivery.
[Source: ZEN]
bridge
A device which forwards traffic between network segments based on
datalink layer information. These segments would have a common
network layer address. See also: gateway, router.
broadband
A transmission medium capable of supporting 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.
broadcast
A special type of multicast packet which all nodes on the network
are always willing to receive. See also: multicast, unicast.
broadcast storm
An incorrect packet broadcast onto a network that causes multiple
hosts to respond all at once, typically with equally incorrect
packets which causes the storm to grow exponentially in severity.
See also: Ethernet meltdown.
brouter
A device which bridges some packets (i.e. forwards based on
datalink layer information) and routes other packets (i.e.
forwards based on network layer information). The bridge/route
decision is based on configuration information. See also: bridge,
router.
BSD
See: Berkeley Software Distribution
BTW
By The Way
Bulletin Board System (BBS)
A computer, and associated software, which typically provides
electronic messaging services, archives of files, and any other
services or activities of interest to the bulletin board system"s
operator. Although BBS"s have traditionally been the domain of
hobbyists, an increasing number of BBS"s are connected directly to
the Internet, and many BBS"s are currently operated by government,
educational, and research institutions. See also: Electronic
Mail, Internet, Usenet.
[Source: NWNET]
Campus Wide Information System (CWIS)
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, databases.
CCIRN
See: Coordinating Committee for Intercontinental Research Networks
CCITT
See: Comite Consultatif International de Telegraphique et
Telephonique
CERT
See: Computer Emergency Response Team
checksum
A computed value which is dependent upon the contents of a packet.
This value is sent along with the packet when it is transmitted.
The receiving system computes a new checksum based upon the
received data and compares this value 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]
CIDR
See: Classless Inter-domain Routing
circuit switching
A communications paradigm in which a dedicated communication path
is established between two hosts, and on which all packets travel.
The telephone system is an example of a circuit switched network.
See also: connection-oriented, connectionless, packet switching.
Classless Inter-domain Routing (CIDR)
A proposal, set forth in RFC1519, to allocate IP addresses so as
to allow the addresses to be aggregated when advertised as routes.
It is based on the elimination of intrinsic IP network addresses;
that is, the determination of the network address based on the
first few bits of the IP address. See also: IP address, network
address, supernet.
client
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]
client-server model
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.
CNI
See: Coalition for Networked Information
Coalition for Networked Information (CNI)
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.
Comite Consultatif International de Telegraphique et Telephonique (
CCITT)
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.
Computer Emergency Response Team (CERT)
The CERT was formed by ARPA in November 1988 in response to the
needs exhibited during the Internet worm incident. The CERT
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.
congestion
Congestion occurs when the offered load exceeds the capacity of a
data communication path.
connection-oriented
The data communication method in which communication proceeds
through three well-defined phases: connection establishment, data
transfer, connection release. TCP is a connection-oriented
protocol. See also: circuit switching, connectionless, packet
switching, Transmission Control Protocol.
connectionless
The data communication method in which communication occurs
between hosts with no previous setup. Packets between two hosts
may take different routes, as each is independent of the other.
UDP is a connectionless protocol. See also: circuit switching,
connection-oriented, packet switching, User Datagram Protocol.
Coordinating Committee for Intercontinental Research Networks (CCIRN)
A committee that includes the United States FNC and its
counterparts in North America and Europe. Co-chaired by the
executive directors of the FNC and the European Association of
Research Networks (RARE), the CCIRN provides a forum for
cooperative planning among the principal North American and
European research networking bodies. See also: Federal Networking
Council, RARE.
[Source: MALAMUD]
core gateway
Historically, one of a set of gateways (routers) operated by the
Internet Network Operations Center at Bolt, Beranek and Newman
(BBN). The core gateway system formed a central part of Internet
routing in that all groups must advertise paths to their networks
from a core gateway.
[Source: MALAMUD]
Corporation for Research and Educational Networking (CREN)
This organization was formed in October 1989, when Bitnet and
CSNET (Computer + Science NETwork) were combined under one
administrative authority. CSNET is no longer operational, but
CREN still runs Bitnet. See also: Bitnet.
[Source: NNSC]
cracker
A cracker is an individual who attempts to access computer systems
without authorization. These individuals are often malicious, as
opposed to hackers, and have many means at their disposal for
breaking 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
Pronnounced "See you, See me," CU-SeeMe is a publicly available
videoconferencing program developed at Cornell University. It
allows anyone with audio/video capabilites and an Internet
connection to videoconference with anyone else with the same
capabilities. It also allows multiple people to tie into the same
videoconference.
CWIS
See: Campus Wide Information system
Cyberspace
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)
A number derived from a set of data that will be transmitted. By
recalculating the CRC at the remote end and comparing it to the
value originally transmitted, the receiving node can detect some
types of transmission errors. See also: checksum.
[Source: MALAMUD]
DANTE
A non-profit company founded in July 1993 to help the European
research community enhance their networking facilities. It
focuses on the establishment of a high-speed computer network
infrastructure.
DARPA
Defense Advanced Research Projects Agency
See: Advanced Research Projects Agency
Data Encryption Key (DEK)
Used for the encryption of message text and for the computation of
message integrity checks (signatures). See also: encryption.
Data Encryption Standard (DES)
A popular, standard encryption scheme. See also: encryption,
Pretty Good Privacy, RSA.
datagram
A self-contained, independent entity of data carrying sufficient
information to be routed from the source to the destination
computer without reliance on earlier exchanges between this source
and destination computer and the transporting network. 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. The functionality of each Phase of the
implementation, such as Phase IV and Phase V, is different.
default route
A routing table entry which is used to direct packets addressed to
networks not explicitly listed in the routing table.
[Source: MALAMUD]
Defense Data Network (DDN)
A global communications network serving the US Department of
Defense composed of MILNET, other portions of the Internet, and
classified networks which are not part of the Internet. The DDN
is used to connect 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)
Previously called "The NIC", the DDN NIC"s primary responsibility
was the assignment of Internet network addresses and Autonomous
System numbers, the administration of the root domain, and
providing information and support services to the Internet for the
DDN. Since the creation of the InterNIC, the DDN NIC performs
these functions only 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 responsible for managing the DDN portion of
the Internet, including the MILNET. Currently, DISA administers
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
established over a phone line (analog or ISDN). See also:
Integrated Services Digital Network.
Directory Access Protocol
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 for 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. The directory user may be a person or
another software element.
[Source: RFC1208]
DISA
See: Defense Information Systems Agency
Distributed Computing Environment (DCE)
An architecture of standard programming interfaces, conventions,
and server functionalities (e.g., naming, distributed file system,
remote procedure call) for distributing applications transparently
across networks of heterogeneous computers. 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 in the
Internet is the Domain Name System.
DIX Ethernet
See: Ethernet
DNS
See: Domain Name System
domain
"Domain" is a heavily overused term in 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)
The DNS is a general purpose distributed, replicated, data query
service. The principal use is the lookup of host IP addresses
based on host names. The style of host names now used in the
Internet is called "domain name", because they are the style of
names 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. The country domain names are
based on ISO 3166. For example, .US (United States), .UK (United
Kingdom), .AU (Australia). See also: Fully Qualified Domain Name,
Mail Exchange Record.
dot address (dotted decimal notation)
Dot address refers to the common notation for IP addresses of the
form A.B.C.D; where each letter represents, in decimal, one byte
of a four byte IP address. 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 a sensing and analysis of
current actual network conditions. NOTE: this does not include
cases of routing decisions taken on 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.
EFF
See: Electronic Frontier Foundation
EGP
See: Exterior Gateway Protocol
Electronic Frontier Foundation (EFF)
A foundation established to address social and legal issues
arising from the impact on society of the increasingly pervasive
use of computers as a means of communication and information
distribution.
Electronic Mail (email)
A system whereby a computer user can exchange messages with other
computer users (or groups of users) via a communications network.
Electronic mail is one of the most popular uses of the Internet.
[Source: NNSC]
email
See: Electronic mail
email address
The domain-based or UUCP address that is 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
The technique used by layered protocols in which a layer adds
header information to the protocol data unit (PDU) 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 in order to
prevent any but the intended recipient from reading that data.
There are many types of data encryption, and they are 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
An event that causes saturation, or near saturation, on an
Ethernet. It usually results from illegal or misrouted packets
and typically lasts only a short time. See also: broadcast storm.
[Source: COMER]
Extended Binary Coded Decimal Interchange Code (EBCDIC)
A standard character-to-number encoding used primarily by IBM
computer systems. See also: ASCII.
Exterior Gateway Protocol (EGP)
A protocol which distributes routing information to the routers
which connect autonomous systems. The term "gateway" is
historical, as "router" is currently the preferred term. There is
also a routing protocol called EGP defined in RFC904. See also:
Autonomous System, Border Gateway Protocol, Interior Gateway
Protocol.
eXternal Data Representation (XDR)
A standard for machine independent data structures developed by
Sun Microsystems and defined in RFCs 1014 and 1832. It is similar
to ASN.1. See also: Abstract Syntax Notation One.
[Source: RFC1208]
FARNET
A non-profit corporation, established in 1987, whose mission is to
advance the use of computer networks to improve research and
education.
FAQ
Frequently Asked Question
FDDI
See: Fiber Distributed Data Interface
Federal Information Exchange (FIX)
One of the connection points between the American governmental
internets and the Internet.
[Source: SURA]
Federal Networking Council (FNC)
The coordinating group of representatives from those federal
agencies involved in the development and use of federal
networking, especially those networks using TCP/IP and the
Internet. 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. 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
The copying of a file from one computer to another over a computer
network. See also: File Transfer Protocol, Kermit, Gopher, World
Wide Web.
File Transfer Protocol (FTP)
A protocol which allows a user on one host to access, and transfer
files to and from, another host over a network. Also, FTP is
usually the name of the program the user invokes to execute the
protocol. See also: anonymous FTP.
finger
A protocol, defined in RFC1288, that allows information about a
system or user on a system to be retrived. Finger also refers to
the commonly used program which retrieves this information.
Information about all logged in users, as well is information
about specific users may be retrieved from local or remote
systems. Some sites consider finger to be a security risk and
have either disabled it, or replaced it with a simple message.
FIX
See: Federal Information Exchange
flame
A strong opinion and/or criticism of something, usually as a frank
inflammatory statement, in an electronic mail message. It is
common to precede a flame with an indication of pending fire (i.e.
FLAME ON!). Flame Wars occur when people start flaming other
people for flaming when they shouldn"t have. 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. See
also: Three Letter Acronym.
FQDN
See: Fully Qualified Domain Name
fragment
A piece of a packet. When a router is forwarding an IP packet to
a network that has a maximum transmission unit smaller than the
packet size, it is forced to break up that packet into multiple
fragments. These fragments will be 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 over which the packet
must pass. See also: reassembly.
frame
A frame is a datalink layer "packet" which contains the header and
trailer information required by the physical medium. That is,
network layer packets are encapsulated to become frames. See
also: datagram, encapsulation, packet.
freenet
Community-based bulletin board system with email, information
services, interactive communications, and conferencing. Freenets
are funded and operated by individuals and volunteers -- in one
sense, like public television. They are part of the National
Public Telecomputing Network (NPTN), an organization based in
Cleveland, Ohio, 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, rather than just its
hostname. For example, "venera" is a hostname and
"venera.isi.edu" is an FQDN. See also: hostname, Domain Name
System.
FYI
For Your Information
FYI
A subseries of RFCs that are not technical standards or
descriptions of protocols. FYIs convey general information about
topics related to TCP/IP or the Internet. See also: Request For
Comments.
gated
Gatedaemon. A program which supports multiple routing protocols
and protocol families. It may be used for routing, and makes an
effective platform for routing protocol research. 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". Currently, a gateway is a communications
device/program which passes data between networks having similar
functions but dissimilar implementations. This should not be
confused 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. Gopher uses a simple protocol,
defined in RFC1436, that allows a single Gopher client to access
information from any accessible Gopher server, providing the user
with a 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, designed to maximize interoperability in areas where
plain OSI standards are ambiguous or allow excessive options.
hacker
A person who delights in having an intimate understanding of the
internal workings of a system, computers and computer networks in
particular. The term is often misused in a pejorative context,
where "cracker" would be the correct term. See also: cracker.
header
The portion of a packet, preceding the actual data, containing
source and destination information. It may also error checking and
other fields. A header is also the part of an electronic mail
message which precedes the body of a message 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. See also:
DECnet, IP, IPX, XNS, homogeneous network.
hierarchical routing
The complex problem of routing on large networks can be simplified
by reducing the size of the networks. This is accomplished 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 encompasses advanced computing,
communications, and information technologies, including 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 components well integrated and linked over a high speed
network.
[Source: HPCC]
High Performance Parallel Interface (HIPPI)
An emerging ANSI standard which extends the computer bus over
fairly short distances at speeds of 800 and 1600 Mb/s. 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. See also:
DECnet, IP, IPX, XNS, heterogeneous network.
hop
A term used in routing. A path to a destination on a network is a
series of hops, through routers, away from the origin.
host
A computer that allows users to communicate with other host
computers on a network. Individual users communicate 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. 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. In ARCnet, a hub is
used to connect several computers together. In a message handling
service, a hub is used for the transfer of messages across the
network.
[Source: MALAMUD]
hyperlink
A pointer within a hypertext document which points (links) to
another document, which may or may not also be a hypertext
document. See also: hypertext.
hypertext
A document, written in HTML, which contains hyperlinks to other
documents, which may or may not also be hypertext documents.
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. It is 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. A formal
standard is still under development in the IETF. See also:
hyperlink, hypertext, Hypertext Markup Language, World Wide Web.
I-D
See: Internet-Draft
IAB
See: Internet Architecture Board
IANA
See: Internet Assigned Numbers Authority
ICMP
See: Internet Control Message Protocol
IEEE
Institute of Electrical and Electronics Engineers
IEEE 802
See: 802.x
IEN
See: Internet Experiment Note
IEPG
See: Internet Engineering Planning Group
IESG
See: Internet Engineering Steering Group
IETF
See: Internet Engineering Task Force
IINREN
See: Interagency Interim National Research and Education Network
IGP
See: Interior Gateway Protocol
IMHO
In My Humble Opinion
IMR
See: Internet Monthly Report
Integrated Services Digital Network (ISDN)
An emerging technology which is beginning to be offered by the
telephone carriers of the world. ISDN combines voice and digital
network services in a single medium, making it possible to offer
customers digital data services as well as voice connections
through a single "wire." The standards that define ISDN are
specified by CCITT. See also: CCITT.
[Source: RFC1208]
Interagency Interim National Research and Education Network (IINREN)
An evolving operating network system. Near term (1992-1996)
research and development activities will provide for the smooth
evolution of this networking infrastructure into the future
gigabit NREN.
[Source: HPCC]
Interior Gateway Protocol (IGP)
A protocol which distributes routing information to the routers
within an autonomous system. The term "gateway" is historical, as
"router" is currently the preferred term. See also: Autonomous
System, Exterior Gateway Protocol, Open Shortest-Path First,
Routing Information Protocol.
Intermediate System (IS)
An OSI system which performs network layer forwarding. It is
analogous to an IP router. See also: Open Systems
Interconnection, router.
Intermediate System-Intermediate System (IS-IS)
The OSI IGP. See also: Open Systems Interconnection, Interior
Gateway Protocol.
International Organization for Standardization (ISO)
A voluntary, nontreaty organization founded in 1946 which is
responsible for creating international standards in many 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)
An agency of the United Nations which coordinates the various
national telecommunications standards so that people in one
country can communicate with people in another country.
International Telecommunications Union -
Telecommunications Standards Sector (ITU-TSS)
The new name for CCITT since the ITU reorganization. The function
is the same; only the name has been changed
internet
While an internet is a network, the term "internet" is usually
used to refer to a collection of networks interconnected with
routers. See also: network.
Internet
(note the capital "I") The Internet is the largest internet in the
world. Is a three level hierarchy composed 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
A 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)
The IAB has been many things over the years. Originally the
Internet Activities Board, it was responsible for the development
of the protocols which make up the Internet. It later 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; this is the charter it holds today. The IAB is
responsible for approving nominations to the IESG, architectural
oversight for Internet Standard Protocols, IETF standards process
oversight and appeals, IANA and RFCactivities, 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)
The central registry for various Internet protocol parameters,
such as 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)
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)
Internet-Drafts are working documents of the IETF, its Areas, and
its Working Groups. As the name implies, Internet-Drafts are
draft documents. They are valid for a maximum of six months and
may be updated, replaced, or obsoleted by other documents at any
time. Very often, I-Ds are precursors to RFCs. See also:
Internet Engineering Task Force, Request For Comments.
Internet Engineering Planning Group (IEPG)
A group, primarily composed 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)
The IESG is composed of the IETF Area Directors and the IETF
Chair. It provides 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)
The IETF is a large, open community of network designers,
operators, vendors, and researchers whose 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 is a major source of proposals for protocol standards
which are 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)
A series of reports pertinent to the Internet. IENs were
published in parallel to RFCs and were intended to be "working
documents." They have been replaced by Internet-Drafts and are
currently of historic value only. See also: Internet-Draft,
Request For Comments.
Internet Monthly Report (IMR)
Published monthly, the purpose of the Internet Monthly Reports is
to communicate to the Internet Research Group the accomplishments,
milestones reached, or problems discovered by the participating
organizations.
internet number
See: internet address
Internet Protocol (IP, IPv4)
The Internet Protocol (version 4), defined in RFC791, is the
network layer for the TCP/IP Protocol Suite. It is 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)
IPv6 (version 5 is a stream protocol used for special
applications) is a new version of the Internet Protocol which is
designed to be an evolutionary step from its predecessor, version
4. There are many RFCs defining various portions 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).
Internet Registry (IR)
The IANA has the discretionary authority to delegate portions of
its responsibility and, with respect to network address and
Autonomous System identifiers, has lodged this responsibility with
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)
A world-wide "party line" protocol that allows one to 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)
The "governing body" of the IRTF. See also: Internet Research
Task Force.
[Source: MALAMUD]
Internet Research Task Force (IRTF)
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, which are each tasked to discuss
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)
The Internet Society is a non-profit, professional membership
organization which facilitates and supports the technical
evolution of the Internet, stimulates interest in and educates the
scientific and academic communities, industry and the public about
the technology, uses and applications of the Internet, and
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)
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
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
The ability of software and hardware on multiple machines from
multiple vendors to communicate meaningfully.
IP (IPv4)
See: Internet Protocol
IPng (IPv6)
See: Internet Protocol Version 6
IP address
The 32-bit address defined by the Internet Protocol in RFC791.
It is usually represented in dotted decimal notation. See also:
dot address, internet address, Internet Protocol, network address,
subnet address, host address.
IP datagram
See: datagram
IPX
See: Internetwork Packet eXchange
IR
See: Internet Registry
IRC
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)
Software that allows OSI services to 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
Joyce K. Reynolds
KA9Q
A popular implementation of TCP/IP and associated protocols for
amateur packet radio systems. See also: TCP/IP Protocol Suite.
[Source: RFC1208]
Kerberos
Kerberos is the security system of MIT"s Project Athena. It is
based on symmetric key cryptography. See also: encryption.
Kermit
A popular file transfer protocol developed by Columbia University.
Because Kermit runs in most operating environments, it provides an
easy method of file transfer. Kermit is NOT the same as FTP. See
also: File Transfer Protocol
[Source: MALAMUD]
Knowbot
A "Knowledge Robot" is a program which 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
An experimental directory service. See also: white pages, whois,
X.500.
LAN
See: Local Area Network
layer
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; 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 the layer to communicate with each other.
TCP/IP has five layers of protocols; OSI has seven. The
advantages 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
This protocol provides access for management and browser
applications that provide read/write interactive access to the
X.500 Directory. See also: X.500.
link
A pointer which may be used to retreive the file or data to which
the pointer points.
list server
An automated mailing list distribution system. List servers
handle the administrivia of mailing list maintenance, such as the
adding and deleting of list members.
little-endian
A format for storage or transmission of 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)
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)
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
No active participation on the part of a subscriber to an mailing
list or USENET newsgroup. A person 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
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
The hardware