jabber JANET JAVA
JAVABeans JAVA Workshop JDBC
JPEG JUNET JVNCnet
jabber An error
condition in which a network device continually transmits garbage onto
the network. In IEEE 802.3, a data
packet whose length exceeds that prescribed in the standard.
Joint Academic Network. The UK Educational and Research network
run by UKERNA.
JAVA An object-oriented
programming language developed at Sun Microsystems
to solve a number of problems in modern programming practice. The Java
language is used extensively within HotJava the world wide web (WWW) browser.
JAVABeans Provides a platform-indipendent,
portable, component model and a rational security model. JavaBeans will
work with ActiveX/COM, OpenDoc, and LiveConnect.
JAVA Workshop Is a commercial
product that provides programmers a comprehensive environment for Java
JDBC (Java Database Connectivity)
JECF (Java Electronic Commerce
Framework). Is a secure, extensible framework for conducting business on
Jitter The slight movement
of a transmission signal in time or phase. Can introduce errors and loss
of synchronization in high-speed synchronous communications
JPEG (Joint Photographic
Expert Group). An image file compression standard established by this group.
It achieves tremendous compression at the cost of introducing distortions
into the image which are almost always imperceptible
JUNET (Japan UNIX Network) Japan
UNIX Network. The largest nationwide, noncommercial network in Japan, designed
to promote communication between Japanese and outside researchers.
JVNCnet John Von Neumann
Center Network. A regional network composed of T1 and slower serial links
providing midlevel networking services to sites in the Northeast.
Karn's algorithm keepalive interval
keepalive message Kerberos Kermit
kernel Kilobyte Knowbot
KA9Q A popular implementation
of TCP/IP and associated protocols for amateur packet radio systems. See
also: TCP/IP Protocol Suite.
Recommendation G.721 [G721] describes the algorithm recommended for conversion
of a 64 KB/s A-law or u-law PCM channel
to and from a 32 KB/s channel. The conversion is applied to the PCM stream
using an Adaptive Differential Pulse Code Modulation (ADPCM)
transcoding technique. This algorithm will be registered with the IANA
for MIME use under the name Audio/32KADPCM..
Karn's algorithm An
algorithm that improves round-trip time estimations by helping transport
layer protocols distinguish between good and bad round-trip time samples.
keepalive interval Period
of time between each keepalive message sent by a network device.
keepalive message Message
sent by one network device to inform another network device that the virtual
circuit between the two is stiull active.
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]
kernel The level of an
operating system or networking system that contains the system-level commands
or all of the functions hidden from the user. In a Unix system, the kernel
is a program that contains the device drivers, the memory management routines,
the scheduler, and system calls. This program is always running while the
system is operating. [Source: ZEN
Kilobyte A thousand bytes.
Actually, usually, 1024 (2^10) bytes. See also: Byte,
Knowbot An experimental
directory service. See also: White
Pages, WHOIS, X.500.
The Royal institute of technology in Stockholm (really "Kungliga
LAN LanLink LAN Manager
LAN Network Manager LAN Server LAP
LAPB LAPD LAPM
LASER LAT LATA
latency LATNet layer
LCD LCN LCP
LDAP LDM LDT
Leased-line LED LEN node
level 1 router level 2 router LIFO
limited resource link line line conditioning
Line Driver line of sight line turnaround
Link link layer link-state routing algorithm
LINX LIPS Lisp
LISTSERV LITNet Little-Endian
LLC LLC2 LMI
LMT LM/X LNM
load balancing Loading LOB
Local acknowledgement local-bridge local loop
local host Local Talk logical channel
loopback-loopback test lossy LRC
LSB LSD LSI
LU LU6.2 Lurking
LAN (Local Area Network).
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:
LanLink Commercial LAN
interconnect (IP, DECnet,
IPX, etc.) service offered by FINNET
group (a consortium of local PNO's).
LAN Manager Distributed
file system developed and supported by Microsoft.
LAN Network Manager Source-bridge
and Token Ring management package provided by IBM. Typically running on
a PC, it monitors source-route bridge and Token Ring devices, and can pass
alerts up to NetView.
LAN Server Distributed
file system derived from LAN Manager, which is develop and supported by
LAP (Link Access Procedure).
LAPB (Link Access Procedure,
Balanced). Derived from HDLC, a CCITT
X.25 version of a bit-oriented
data link protocol.
LAPD (Link Access Procedure
'D'). ISDN's link-layer protocol for
the D channel. LAPD was derived from the CCITT X.25
LAPB protocol and is designed primarily
to satisfy the signaling requirements of ISDN Basic Access. Defined by
CCITT Recommendations Q.920 and Q.921.
LAPM (Link Access Procedure
for Modems). Protocol which controls the handshake between two modems.
LASER (Light Amplification
by Stimulated Emission of Radiation). Analog transmission device in which
a suitable active material is excited by an external stimulus to produce
a narrow beam of coherent light that can be modulated into pulses to carry
data. Networks based on LASER technology are still in their infancy, but
show promise dure to potentially high bandwidths are relative resistence
LAT (Local Area Transport).
A network virtual terminal protocol developed by Digital Equipment Corporation.
LATA (Local Access
and Transport Area). A telephone dialing area serviced by a single local
telephone company. Calls within LATAs are called local calls. There are
well over 100 lATAs in the U.S.
latency The amount
of time between when a device requests access to a network and when it
is granted permission to transmit.
The Latvian Academic and Research 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. [Source: RFC1392]
LCD (Liquid Crystal Display).
A display device similar to those used in in pocket calculators.
LCN (Logical Channel Number).
LCP (Link Control Protocol).
The LCP is used to automatically agree upon the encapsulation format options,
handle varying limits on sizes of packets, authenticate the identity of
its peer on the link, determine when a link is functioning properly and
when it is defunct, detect a looped-back link and other common misconfiguration
errors, and terminate the link. For more information see: RFC
LDAP (Lightweight Directory
Access Protocol). Is Netscapes strategic directory protocol. It defines
a reasonably simple mechanism for Internet clients to query and manage
an arbitrary database of hierarchical attribute/value pairs over a TCP/IP
connection (port 389). LDAP, a simplification of the X.500
directory access protocol (DAP)
LDM (Limited Distance Modem).
LDT (Local Descriptor Code).
Leased-line A telephone
line reserved for the exclusive use of a customer, without inter-change
LED (Light Emitting Diode).
A display element.
LEN node (Low-Entry
Networking node). End systenms similar to end nodes but which cannot rely
on network nodes (NN) for APPN services
and therefore must have a statically defined image of the APPN network.
A PU 2.1 that supports LSI
LU protocols but does not support CP-CP
level 1 router A device
that routes within a DECnet or OSI
level 2 router A device
that routes between DECnet or OSI
areas. All Level 2 routers must form a contiguous network.
LIFO (Last In, First Out).
limited resource link Resource
defined by device operator to remain active only when being used.
line Generally, another
word for link. In SNA, a connection to the network.
line conditioning The
use of equipment on leased voice-grade channels to improve analog characteristics,
thereby allowing higher transmission rates.
Line Driver A signal
converter which conditions a digital signal to ensure reliable transmission
over an extended distance
line of sight Characteristic
of certain transmission systems such as LASER,
microwave, and infrared systems in which no obstruction on a direct path
between transmitter and receiver may exist.
line turnaround The
time required to change data transmission direction on a phone line.
Link In Data Communication
a connection between two pieces of equipment. Also referred to as point-to-point.
Network communications channel consisting of a circuit or transmission
path, including all equipment, between a sender and a receiver. Most often
used to refer to a WAN connection.
Sometimes referred to as a line.
link layer See data
link-state routing algorithm A
routing algorithm in which each router broadcasts or multicasts information
on the cost of reaching each of its neighbors to all nodes in the internetwork.
Link-state algorithms create a consistent view of the network and are therefore
not very prone to routing loops, but they achieve this at the cost of relatively
greater computational difficulty and somewhat more widespread traffic (comparedwith
distance vector routing algorithms). See also distance vector routing algorithm.
LINX (London INternet eXchange).
An Internet interconnect point at Telehouse, London, where all UK and many
European providers exchange traffic.
LIPS (Logical Instructions
Lisp (LISt Processing).
An interpreted programming language that uses list identifying the relationships
of symbolic values as the fundamental data structure. Lisp is regularly
used in artificial-intelligence research.
LISTSERV Is a distribution
list management package. It runs on IBM VM/CMS systems in the international
NJE network (Bitnet/EARN).
It allows groups of computer users with a common interest to communicate
among themselves, while making efficient use of computer and network resources.
It makes it easy for even novice users to discover, join, and partecipate
in these interest group mailing lists. LISTSERV also provides facilities
for logging and archiving of mail traffic, file server functions and database
searches of archives and files. [Source: EARN Association]
For a list of available groups in the world surf on tile.net/tile/listserv.
The Lithuanian University and Research Network.
format for storage or transmission of binary data in which the least significant
byte (bit) comes first. See Big-Endian.
LLC (Logical Link Control).
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. [Source: RFC1392]
LLC2 (Logical Link
Control, type 2). A connection-oriented OSI
logical link control sublayer protocol.
LMI (Local Management
Interface) for Frame Relay.
Packet containing sequence-number exchange between a DTI (router) and a
switch. It is used by the switch to learn which DLCIs are defined and the
current status of the DLCIs.
LMT (ANSI LMI).
LM/X LAN Manager for
LNM (LAN Network Manager).
An IBM product for managing a collection of source-route bridges and their
Token Ring environments.
load balancing In routing,
the ability of a router to distribute traffi c over all its network ports
that are the same distance from the destination address. Good load-balancing
algorithms use both line speed and reliability information. Load balancing
increases the utilization of network segments, thus increasing effective
Loading The addition
of inductance to a line in order to minimize amplitude distortion. Used
commonly on public telephone lines to improve voice quality and makes the
lines impassable to high-speed data
LOB (Low-Order Byte).
Local acknowledgement A
method whereby an intermediate network node, such as a Cisco router, terminates
a data link layer session for an end host. Use of local acknowledgement
reduces network overhead and, therefore, the risk of time-outs.
local-bridge A bridge
that directly interconnects networks in the same geographic area.
local loop The line
from a telephone subscribe's premises to the telephone company CO.
local host In UNIX the host
on the network which you are currently using.
Local Talk Apple's
proprietary 230-Kbps baseband CSMA/CD
logical channel A nondedicated,
packet-switched communications path between two or more network nodes.
Through packet switching, many logical channels can exist simultaneously
on a single physical channel.
login Noun or a verb. Noun:
The account name used to gain access to a computer system. Not a secret
(contrast with Password) Verb: The act of entering into a computer system,
e.g. "Login to the WELL and then go to the GBN conference." See also: password.
loop Route where packets
never reach the destination, but simply cycle repeatedly through a constant
series of network nodes.
Loopback A type of diagnostic
test in which the transmitted signals is returned to the sending device
after passing through all or part of a communications link or network.
A loopback test permits the comparison of a returned signal with the transmitted
of a network that is prone to lose packets when it becomes highly loaded.
LRC (Longitudinal Redundancy
Check). Error detection algorithm.
LSB (Least-Significant Bit
LSD (Least-Significant Digit).
LSI (Large-Scale Integration).
LU (Logical Unit). A primary
component of SNA, an LU is a type of
NAU that enables end users to communicate
with each other and gain access to SNA network resources.
LU6.2 (Logical Unit 6.2).
An LU governing peer-to-peer SNA communications.
LU 6.2 supports general communication between programs in a distributed
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]
LYNX Lynx is a fully-featured
World Wide Web (WWW) client for
users running cursor-addressable, character-cell display devices (e.g.,
vt100 terminals, vt100 emulators running on PCs or Macs, or any other "curses-oriented"
display). It will display hypertext markup language (HTML)
hypertext documents containing links to files residing on the local system,
as well as files residing on remote systems running Gopher,
WAIS, and NNTP