Glossary - 7

IP. Internet Protocol. The IP part of the TCP/IP communications protocol. IP implements the network layer (layer
3) of the protocol, which contains a network address and is used to route a message to a different network
or subnetwork. IP accepts “packets” from the layer 4 transport protocol (TCP or UDP), adds its own header
to it and delivers a “datagram” to the layer 2 data link protocol. It may also break the packet into fragments
to support the maximum transmission unit (MTU) of the network.
IP Address. (Internet Protocol address) The address of a computer attached to an IP network. Every client and
server station must have a unique IP address. A 32-bit address used by a computer on a IP network. Client
workstations have either a permanent address or one that is dynamically assigned to them each session.
IP addresses are written as four sets of numbers separated by periods; for example, 204.171.64.2.
IPX/SPX. Internet Package Exchange/Sequential Packet Exchange. A communications protocol for Novell. IPX
is Novell’s Layer 3 protocol, similar to XNS and IP, and used in NetWare networks. SPX is Novell's version
of the Xerox SPP protocol.
IS-95. Interim Standard 95. The EIA/TIA standard that governs the operation of CDMA cellular service. Versions
include IS-95A and IS-95B. See CDMA.
K
Kerberos. Kerberos is a network authentication protocol. It is designed to provide strong authentication for
client/server applications by using secret-key cryptography. A free implementation of this protocol is
available from the Massachusetts Institute of Technology. Kerberos is available in many commercial
products as well.
Key. A key is the specific code used by the algorithm to encrypt or decrypt the data. Also see, Encryption and
Decrypting.
L
LAN. Local area network. A radio network that supports data communication within a local area, such as within
a warehouse of building.
LASER. Light Amplification by Stimulated Emission of Radiation.The laser is an intense light source. Light from
a laser is all the same frequency, unlike the output of an incandescent bulb. Laser light is typically co herent
and has a high energy density.
Laser Diode. A gallium-arsenide semiconductor type of laser connected to a power source to generate a laser
beam. This laser type is a compact source of coherent light.
Laser Scanner. A type of bar code reader that uses a beam of laser light.
LCD. See Liquid Crystal Display.
LED Indicator. A semiconductor diode (LED - Light Emitting Diode) used as an indicator, often in digital
displays. The semiconductor uses applied voltage to produce light of a certain frequency determined by the
semiconductor's particular chemical composition.