Specifications

Glossary
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Properties of IP Address Classes
Every IP address consists of two parts: the network ad-
dress and the host address. The sizes of the network ad-
dress and the host address are variable, and determined
by the first four bits (of the first byte) of the IP address.
IP
masquerading
By means of IP masquerading a computer or LAN can be
protected from unauthorized connection requests from
the Internet. Masquerading works by converting the IP ad-
dresses used in a network to one public IP address. From
the outside it appears that all requests are sent from a sin-
gle computer.
IP network A network in which data exchange takes place on the ba-
sis of the Internet Protocol is called an IP network.
outside dialing
prefix
The outside dialing prefix is the digit dialed at an exten-
sion line to obtain an outside line. Generally this is “0”.
public IP
address
A public IP address is an IP address valid in the Internet.
Every computer or router participating in the Internet must
have a uniquely assigned public IP address. This address
is usually negotiated dynamically with the Internet Service
Provider when a connection to the Internet is dialed. The
Internet Service Provider assigns the negotiated IP ad-
dress to the computer or router for the duration of an Inter-
net session.
port So that a single network connection on a computer can be
used by multiple applications to exchange data with re-
mote sites at the same time, a computer administers what
are known as ports for the IP-based protocols TCP and
UDP. Ports substantiate the point of access for the data
packets delivered via the IP Internet protocol. While the IP
address determines the destination computer quite gen-
erally, the port addresses the communication interface
provided by an application for a certain communication
procedure.
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