Fujitsu LifeBook NH751 User Manual page 128

Within an isolated network, you can assign IP addresses at random as l ong as each one is unique. However ,
connecting a private network to the Internet requires using registered IP addresses (called Internet
addresses) to avoid duplicates.
The four numbers in an IP address are used in different ways to identify a particular network and a host
on that network. Three regional Internet registries -- ARIN, RIPE NCC and APNIC -- assign Internet
addresses from the following three classes.
Class A - supports 16 million hosts on each of 126 networks
Class B - supports 65,000 hosts on each of 16,000 networks
Class C - supports 254 hosts on each of 2 million networks
The number of unassigned Internet addresses is running out, so a new classless scheme called CIDR is
gradually replacing the system based on classes A, B, and C and is tied to adoption of IPv6.
IR
An abbreviation for infrared.
IrDA
Infrared Data Association. An organization which produces standards for communication using infrared
as the carrier.
IRQ
Interrupt Request. An acronym for the hardware signal to the CPU that an external event has occurred
which needs to be processed.
KB
Kilobyte. One thousand bytes.
LAN
Local Area Network. An interconnecti o n of computers and peripherals wi t hin a single limited geographic
location which can pass programs and data amongst themselves.
122 - Glossary