network components of the local network are hidden behind the router's IP address reg-
istered on the Internet. Because of this security function, NAT is frequently used as part
of the

Firewall

of a network. If you want to make services on a PC in the local network

available on the Internet despite NAT, you can configure the Gigaset SX763 WLAN dsl as
a

Virtual server

Network
A network is a group of devices connected in wired or wireless mode so that they can
share resources such as data and peripherals. A general distinction is made between
local networks (

LANs

) and wide-area networks (

WANs

Network adapter
The network adapter is the hardware device that creates the connection between a net-
work component and a local network. The connection can be wired or wireless. An Eth-
ernet network card is an example of a wired network adapter. The Gigaset PC Card 108
and the Gigaset USB Adapter 108 are examples of wireless network adapters.
A network adapter has a unique address, the

MAC address

Public IP address
The public

IP address

(also known as the global IP address) is a network component's

address on the

Internet

. It is assigned by the

Internet service provider

. Devices that cre-

ate a link from a LAN to the Internet, such as the Gigaset SX763 WLAN dsl, have a public
and a

Private IP address

PBX
Private Branch Exchange
PBX is the English acronym for a public branch exchange, which allows connection and
configuration of extensions and telephone functions.

Port
Data is exchanged between two applications in a network across a port. The port
number addresses an application within a network component. The combination of

address

/port number uniquely identifies the recipient or sender of a data packet within

a network. Some applications (e.g. Internet services such as HTTP or FTP) work with
fixed port numbers; others are allocated a free port number whenever they need one.