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.
interoperability
The ability of software and hardware on multiple machines from
multiple vendors to communicate meaningfully.
IP
See: Internet Protocol
IP address
The 32-bit address defined by the Internet Protocol in STD 5, RFC
791. 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
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
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.
listserv
An automated mailing list distribution system originally designed
for the Bitnet/EARN network. See also: Bitnet, European Academic
Research Network, mailing list.
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, 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]
MAC
See: Media Access Control
MAC address
The hardware address of a device connected to a shared media. See
also: Media Access Control, Ethernet, token ring.
[Source: MALAMUD]
mail bridge
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)
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
Part of an electronic mail delivery system which 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
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
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
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
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 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
should ALWAYS be sent to the list's "-request" address (e.g.,
ietf-request@cnri.reston.va.us for the IETF mailing list). See
also: Electronic Mail, mail exploder.
MAN
See: Metropolitan Area Network
Management Information Base (MIB)
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
A humorous term applied to packets that turn up unexpectedly on
the wrong network because of bogus routing entries. 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)
The largest frame length which may be sent on a physical medium.
See also: fragmentation, frame.
Media Access Control (MAC)
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 switching
See: packet switching
Metropolitan Area Network (MAN)
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
mid-level network
Mid-level networks (a.k.a. regionals) make up the second level of
the Internet hierarchy. They are the transit networks which
connect the stub networks to the backbone networks. See also:
backbone, Internet, stub network, transit network.
MIME
See: Multipurpose Internet Mail Extensions
moderator
A person, or small group of people, who manage moderated mailing
lists and newsgroups. Moderators are responsible for determining
which email submissions are passed on to list. See also:
Electronic Mail, mailing list, Usenet.
MTU
See: Maximum Transmission Unit
MUD
See: Multi-User Dungeon
multicast
A packet with a special destination address which multiple nodes
on the network may be willing to receive. See also: broadcast.
multihomed host
A host which has more than one connection to a network. The host
may send and receive data over any of the links but will not route
traffic for other nodes. See also: host, router.
[Source: MALAMUD]
Multipurpose Internet Mail Extensions (MIME)
An extension to Internet email which provides the ability to
transfer non-textual data, such as graphics, audio and fax. It is
defined in RFC1341. See also: Electronic Mail
Multi-User Dungeon (MUD)
Adventure, role playing games, or simulations played on the
Internet. Devotees call them "text-based virtual reality
adventures". 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
See: Mail Exchange Record
NAK
See: Negative Acknowledgment
name resolution
The process of mapping a name into its corresponding address. See
also: Domain Name System.
[Source: RFC1208]
namespace
A commonly distributed set of names in which all names are unique.
[Source: MALAMUD]
National Institute of Standards and Technology (NIST)
United States governmental body that provides assistance in
developing standards. Formerly the National Bureau of Standards.
[Source: MALAMUD]
National Research and Education Network (NREN)
The NREN is the realization of an interconnected gigabit computer
network devoted to Hign Performance Computing and Communications.
See also: HPPC, IINREN.
[Source: HPCC]
National Science Foundation (NSF)
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, is an essential part of
academic and research communications. It is a highspeed "network
of networks" which is hierarchical in nature. At the highest
level, it is a backbone network currently comprising 16 nodes
connected to a 45Mb/s facility which spans the continental United
States. Attached to that are mid-level networks and attached to
the mid-levels are campus and local networks. NSFNET also has
connections out of the U.S. to Canada, Mexico, Europe, and the
Pacific Rim. The NSFNET is part of the Internet.
Negative Acknowledgment (NAK)
Response to receipt of a corrupted packet of information. See
also: Acknowledgement.
netiquette
A pun on "etiquette" referring to proper behavior on a network.
Netnews
See: Usenet
network
A computer network is a data communications system which
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
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)
A protocol developed by Sun Microsystems, and defined in RFC1094,
which allows a computer system to 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
is now a de facto Internet standard.
[Source: NNSC]
Network Information Center (NIC)
A NIC provides information, assistance and services to network
users. See also: Network Operations Center.
Network Information Services (NIS)
A set of services, generally provided by a NIC, to assist users in
using the network. See also: Network Information Center.
Network News Transfer Protocol (NNTP)
A protocol, defined in RFC977, for the distribution, inquiry,
retrieval, and posting of news articles. See also: Usenet.
network number
See: network address
Network Operations Center (NOC)
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)
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. It is defined in STD 12, RFC1119. See
also: Internet.
[Source: NNSC]
NFS
See: Network File System
NIC
See: Network Information Center
NIC.DDN.MIL
This is the domain name of the DDN NIC. See also: Defense Data
Network..., Domain Name System, Network Information Center.
NIS
See: Network Information Services
NIST
See: National Institute of Standards and Technology
NNTP
See: Network News Transfer Protocol
NOC
See: Network Operations Center
Nodal Switching System (NSS)
Main routing nodes in the NSFnet backbone. See also: backbone,
National Science Foundation.
[Source: MALAMUD]
node
An addressable device attached to a computer network. See also:
host, router.
NREN
See: National Research and Education Network
NSF
See: National Science Foundation
NSS
See: Nodal Switching System
NTP
See: Network Time Protocol
OCLC
See: Online Computer Library Catalog
octet
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
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 Interior Gateway Protocol (OSPF)
A link state, as opposed to distance vector, routing protocol. It
is an Internet standard IGP defined in RFC1247. See also:
Interior Gateway Protocol, Routing Information Protocol.
Open Systems Interconnection (OSI)
A suite of protocols, designed by ISO committees, to be the
international standard computer network architecture. See also:
International Organization for Standardization.
OSI
See: Open Systems Interconnection
OSI Reference Model
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
See: Open Shortest-Path First Interior Gateway Protocol
packet
The unit of data sent across a network. "Packet" a generic term
used to describe 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)
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)
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
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
Public Domain
PDU
See: Protocol Data Unit
PEM
See: Privacy Enhanced Mail
PING
See: Packet INternet Groper
Point Of Presence (POP)
A site where there exists a collection of telecommunications
equipment, usually digital leased lines and multi-protocol
routers.
Point-to-Point Protocol (PPP)
The Point-to-Point Protocol, defined in RFC1171, provides a
method for transmitting packets over serial point-to-point links.
See also: Serial Line IP.
[Source: FYI4]
POP
See: Post Office Protocol and Point Of Presence
port
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)
A protocol designed to allow single user hosts to read mail from a
server. There are three versions: POP, POP2, and POP3. Latter
versions are NOT compatible with earlier versions. See also:
Electronic Mail.
Postal Telegraph and Telephone (PTT)
Outside the USA, PTT refers to a telephone service provider, which
is usually a monopoly, in a particular country.
postmaster
The person responsible for taking care of electronic mail
problems, answering queries about users, and other related work at
a site. See also: Electronic Mail.
[Source: ZEN]
PPP
See: Point-to-Point Protocol
Privacy Enhanced Mail (PEM)
Internet email which provides confidentiality, authentication and
message integrity using various encryption methods. See also:
Electronic Mail, encryption.
Prospero
A distributed filesystem which provides the user with the ability
to create multiple views of a single collection of files
distributed across the Internet. Prospero provides a file naming
system, and file access is provided by 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
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
A device/program which translates between different protocols
which serve similar functions (e.g., TCP and TP4).
Protocol Data Unit (PDU)
"PDU" is internationalstandardscomitteespeak for packet. See
also: packet.
protocol stack
A layered set of protocols which work together to provide a set of
network functions. See also: layer, protocol.
proxy ARP
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
See: Packet Switch Node.
PTT
See: Postal, Telegraph and Telephone
queue
A backup of packets awaiting processing.
RARE
See: Reseaux Associes pour la Recherche Europeenne
RARP
See: Reverse Address Resolution Protocol
RBOC
Regional Bell Operating Company
RCP
See: Remote copy program
Read the F*cking Manual (RTFM)
This acronym is often used when someone asks a simple or common
question.
reassembly
The IP process in which a previously fragmented packet is
reassembled before being passed to the transport layer. See also:
fragmentation.
recursive
See: recursive
regional
See: mid-level network
remote login
Operating on a remote computer, using a protocol over a computer
network, as though locally attached. See also: Telnet.
Remote Procedure Call (RPC)
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 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
A device which propagates electrical signals from one cable to
another. See also: bridge, gateway, router.
Request For Comments (RFC)
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 RFCseries of documents 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: For
Your Information, STD.
Reseaux Associes pour la Recherche Europeenne (RARE)
European association of research networks.
[Source: RFC1208]
Reseaux IP Europeenne (RIPE)
A collaboration between European networks which use the TCP/IP
protocol suite.
Reverse Address Resolution Protocol (RARP)
A protocol, defined in RFC903, 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
See: Request For Comments
RFC822
The Internet standard format for electronic mail message headers.
Mail experts often refer to "822 messages". The name comes from
"RFC822", which contains the specification (STD 11, RFC822).
822 format was previously known as 733 format. See also:
Electronic Mail.
[Source: COMER]
RIP
See: Routing Information Protocol
RIPE
See: Reseaux IP Europeenne
Round-Trip Time (RTT)
A measure of the current delay on a network.
[Source: MALAMUD]
route
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
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
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
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
A set of routers exchanging routing information within an
administrative domain. See also: Administrative Domain, router.
Routing Information Protocol (RIP)
A distance vector, as opposed to link state, routing protocol. It
is an Internet standard IGP defined in STD 34, RFC1058 (updated
by RFC1388). See also: Interior Gateway Protocol, Open Shortest
Path First....
RPC
See: Remote Procedure Call
RTFM
See: Read the F*cking Manual
RTT
See: Round-Trip Time
Serial Line IP (SLIP)
A protocol used to run IP over serial lines, such as telephone
circuits or RS-232 cables, interconnecting two systems. SLIP is
defined in RFC1055. See also: Point-to-Point Protocol.
server
A provider of resources (e.g., file servers and name servers).
See also: client, Domain Name System, Network File System.
SIG
Special Interest Group
signature
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)
A protocol, defined in STD 10, RFC821, used to transfer
electronic mail between computers. It is a server to server
protocol, so other protocols are used to access the messages. See
also: Electronic Mail, Post Office Protocol, RFC822.
Simple Network Management Protocol (SNMP)
The Internet standard protocol, defined in STD 15, RFC1157,
developed to manage nodes on an IP network. It is currently
possible to manage wiring hubs, toasters, jukeboxes, etc. See
also: Management Information Base.
SLIP
See: Serial Line IP
SMDS
See: Switched Multimegabit Data Service
SMI
See: Structure of Management Information
SMTP
See: Simple Mail Transfer Protocol
SNA
See: Systems Network Architecture
snail mail
A pejorative term referring to the U.S. postal service.
SNMP
See: Simple Network Management Protocol
STD
A subseries of RFCs that specify Internet standards. The official
list of Internet standards is in STD 1. See also: For Your
Information, Request For Comments.
stream-oriented
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)
The rules used to define the objects that can be accessed via a
network management protocol. This protocol is defined in STD 16,
RFC1155. See also: Management Information Base.
[Source: RFC1208]
stub network
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
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
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
See: address mask
subnet number
See: subnet address
Switched Multimegabit Data Service (SMDS)
An emerging high-speed datagram-based public data network service
developed by Bellcore and expected to be widely used by telephone
companies as the basis for their data networks. See also:
Metropolitan Area Network.
[Source: RFC1208]
Systems Network Architecture (SNA)
A proprietary networking architecture used by IBM and IBM-
compatible mainframe computers.
[Source: NNSC]
T1
An AT&T term for a digital carrier facility used to transmit a
DS-1 formatted digital signal at 1.544 megabits per second.
T3
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
See: Terminal Access Controller (TAC)
talk
A protocol which allows two people on remote computers to
communicate in a real-time fashion. See also: Internet Relay
Chat.
TCP
See: Transmission Control Protocol
TCP/IP Protocol Suite
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. See also: IP, ICMP,
TCP, UDP, FTP, Telnet, SMTP, SNMP.
TELENET
A public packet switched network using the CCITT X.25 protocols.
It should not be confused with Telnet.
Telnet
Telnet is the Internet standard protocol for remote terminal
connection service. It is defined in STD 8, RFC854 and extended
with options by many other RFCs.
Terminal Access Controller (TAC)
A device which connects terminals to the Internet, usually using
dialup modem connections and the TACACS protocol.
terminal emulator
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
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)
A tribute to the use of acronyms in the computer field. See also:
Extended Four Letter Acronym.
Time to Live (TTL)
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
See: Three Letter Acronym
TN3270
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
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
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]
transceiver
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
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)
An Internet Standard transport layer protocol defined in STD 7,
RFC793. It is connection-oriented and stream-oriented, as
opposed to UDP. See also: connection-oriented, stream-oriented,
User Datagram Protocol.
Trojan Horse
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. See RFC1135.
TTFN
Ta-Ta For Now
TTL
See: Time to Live
tunnelling
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
A type of cable in which pairs of conductors are twisted together
to produce certain electrical properties.
UDP
See: User Datagram Protocol
Universal Time Coordinated (UTC)
This is Greenwich Mean Time.
[Source: MALAMUD]
UNIX-to-UNIX CoPy (UUCP)
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
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 phenonmenon 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]
Usenet
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)
An Internet Standard transport layer protocol defined in STD 6,
RFC768. It is a connectionless protocol which adds a level of
reliability and multiplexing to IP. See also: connectionless,
Transmission Control Protocol.
UTC
See: Universal Time Coordinated
UUCP
See: UNIX-to-UNIX CoPy
virtual circuit
A network service which provides connection-oriented service
regardless of the underlying network structure. See also:
connection-oriented.
virus
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
See: World Wide Web
WAIS
See: Wide Area Information Servers
WAN
See: Wide area network
WG
Working Group
white pages
The Internet supports several databases that contain basic
information about users, such as email 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, WHOIS, X.500.
WHOIS
An Internet program which allows users to query a database of
people and other Internet entities, such as domains, networks, and
hosts, kept at the DDN NIC. The information for people shows a
person's company name, address, phone number and email address.
See also: Defense Data Network Network ..., white pages, Knowbot,
X.500.
[Source: FYI4]
Wide Area Information Servers (WAIS)
A distributed information service which offers 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. Public domain
implementations are available. See also: archie, Gopher,
Prospero.
Wide Area Network (WAN)
A network, usually constructed with serial lines, which covers a
large geographic area. See also: Local Area Network, Metropolitan
Area Network.
World Wide Web (WWW or W3)
A hypertext-based, distributed information system created by
researchers at CERN in Switzerland. Users may create, edit or
browse hypertext documents. The clients and servers are freely
available.
worm
A computer program which replicates itself and is self-
propagating. 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. 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.
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.
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 network developed by Xerox corporation. Implementations exist
for both 4.3BSD derived systems, as well as the Xerox Star
computers.
XNS
See: Xerox Network System
Yellow Pages (YP)
A service used by UNIX administrators to manage databases
distributed across a network.
YP
See: Yellow Pages
zone
A logical group of network devices (AppleTalk).
References
BIG-LAN "BIG-LAN Frequently Asked Questions Memo", BIG-LAN DIGEST
V4:I8, February 14, 1992.
COMER Comer, D., "Internetworking with TCP/IP: Principles,
Protocols and Architecture", Prentice Hall, Englewood Cliffs,
NJ, 1991.
FYI4 Malkin, G., and A. Marine, "FYI on Questions and Answers:
Answers to Commonly asked "New Internet User" Questions", FYI
4, RFC1325, 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, C., "Analyzing Sun Networks", Van Nostrand Reinhold,
New York, NY, 1992.
NNSC "NNSC's Hypercard Tour of the Internet".
LAQUEY LaQuey, T. (with J. Ryer), "The Internet Companion: A
Beginner's Guide to Global Networking", Addison-Wesley,
Reading, MA, 1992.
NWNET Kochmer, J., and NorthWestNet, "The Internet Passport:
NorthWestNets Guide to Our World Online", NorthWestNet,
Bellevue, WA, 1992.
RFC1208 Jacobsen, O., and D. Lynch, "A Glossary of Networking Terms",
RFC1208, Interop, Inc., March 1991.
STD1 Postel, J., "IAB Official Protocol Standards", STD 1, RFC
1360, Internet Architecture Board, September 1992.
STD2 Reynolds, J., and J. Postel, "Assigned Numbers", STD 2, RFC
1340, USC/Information Sciences Institute, July 1992.
TAN Tanenbaum, A., "Computer Networks; 2nd ed.", Prentice Hall,
Englewood Cliffs, NJ, 1989.
ZEN Kehoe, B., "Zen and the Art of the Internet", February 1992.
Security Considerations
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, Privacy Enhanced
Mail (PEM), Trojan Horse, virus, and worm.
Authors' Addresses
Gary Scott Malkin
Xylogics, Inc.
53 Third Avenue
Burlington, MA 01803
Phone: (617) 272-8140
EMail: gmalkin@Xylogics.COM
Tracy LaQuey Parker
University of Texas at Austin
Computation Center
Austin, TX 78712
Phone: (512) 471-2444
EMail: tracy@utexas.edu