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Glossary

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Glossary

Access point

An access point, such as the Gigaset SE587 WLAN dsl, is the centre of a wireless local

network (

WLAN

). It handles the connection of the wireless linked network components

and regulates data traffic in the wireless network. The access point also serves as an

interface to other networks, for example an existing

Ethernet

LAN or via a modem to the

Internet

. The operating mode of wireless networks with an access point is called

Infrastructure mode

.

Ad-hoc mode

Ad-hoc mode describes wireless local networks (

WLANs

) in which the network compo-

nents set up a spontaneous network without an

Access point

, for example several Note-

books in a conference. All the network components are peers. They must have a wire-

less

Network adapter

.

ADSL

Asymmetric Digital Subscriber Line (ADSL) and ADSL 2+ are special types of

DSL

data

transfer technology.

AES

Advanced Encryption Standard

AES is an encryption system published as a standard in October 2000 by the National

Institute of Standards and Technology (NIST). It is used for

WPA

encryption. A distinction

is made between the three AES variants AES-128, AES-192 and AES-256 on the basis of

the key length.

Auto connect

Auto connect means that applications such as Web browser, Messenger and E-mail

automatically open an

Internet

connection when they are launched. This can lead to

high charges if you are not using a

Flat rate

. To avoid this, you can select the manual

connection option on the Gigaset SE587 WLAN dsl.

Bridge

A bridge connects several network segments to form a joint network, for example to

make a

TCP/IP

network. The segments can have different physical characteristics, for

example different cabling as with

Ethernet

and wireless LANs. Linking individual seg-

ments via bridges allows local networks of practically unlimited size.

See also:

Switch

,

Hub

,

Router

,

Gateway

Broadcast

A broadcast is a data packet not directed to a particular recipient but to all the network

components in the network. The Gigaset SE587 WLAN dsl does not pass on broadcast

packets; they always remain within the local network (

LAN

) it administers.

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Glossary

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BSSID

Basic Service Set ID

BSSID permits unique differentiation of one wireless network (

WLAN

) from another. In

Infrastructure mode

, the BSSID is the

MAC address

of the

Access point

. In wireless net-

works in

Ad-hoc mode

, the BSSID is the MAC address of any one of the participants.

Client

A client is an application that requests a service from a

server

. For example, an HTTP cli-

ent on a PC in a local network requests data, i.e. Web pages from an HTTP server on the

Internet

. Frequently the network component (e.g. the PC) on which the client applica-

tion is running is also called a client.

DHCP

Dynamic Host Configuration Protocol

DHCP handles the automatic assignment of

IP addresses

to network components. It was

developed because of the complexity involved in defining IP addresses in large networks

– especially the

Internet

– as participants frequently move, drop out or new ones join.

A DHCP server automatically assigns the connected network components (DHCP

Cli-

ents

)

Dynamic IP addresses

from a defined

IP pool range

thus saving a great deal of con-

figuration work. In addition, the address blocks can be used more effectively: Since not

all participants are on the network at the same time, the same IP address can be

assigned to different network components in succession as and when required.

The Gigaset SE587 WLAN dsl includes a DHCP server and uses it to assign IP addresses

automatically to PCs in the local network. You can specify that the IP addresses for cer-

tain PCs are never changed.

DHCP server

See

DHCP

DMZ

Demilitarised Zone

DMZ describes a part of a network that is outside the

Firewall

. A DMZ is set up, as it

were, between a network you want to protect (e.g. a

LAN

) and a non-secure network

(e.g. the

Internet

). A DMZ is useful if you want to offer

Server

services on the Internet

that are not to be run from behind the firewall for security reasons, or if Internet appli-

cations do not work correctly behind a firewall. A DMZ permits unrestricted access from

the Internet to only one or a few network components, while the other network com-

ponents remain secure behind the firewall.

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DNS

Domain Name System

DNS permits the assignment of IP addresses to computers or

Domain names

that are

easier to remember. A DNS server must administer this information for each

LAN

with

an

Internet

connection. As soon as a page on the Internet is called up, the browser

obtains the corresponding IP address from the DNS server so that it can establish the

connection.

On the Internet, the assignment of domain names to IP addresses follows a hierarchical

system. A local PC only knows the address of the local name server. This in turn knows

all the addresses of the PCs in the local network and the superordinate name servers,

which again know addresses of the next superordinate name servers.

DNS server

See

DNS

Domain name

The domain name is the reference to one or more Web servers on the

Internet

. The

domain name is mapped via the

DNS

service to the corresponding

IP address

.

DoS attack

Denial of Service

A DoS attack is a particular form of hacker attack directed at computers and networks

with a connection to the

Internet

. The aim is not so much to steal data but to paralyse

the computer or network so severely that the network resources are no longer available.

A typical hacker attack involves making a remote computer announce that it is acting

for the paralysed computer, for example, and receive the data intended for you.

DSL

Digital Subscriber Line

DSL is a data transfer technique in which a connection to the

Internet

can be run at high

speed over normal telephone lines. A DSL connection is provided by an

Internet service

provider

. It requires a DSL modem.

Dynamic IP address

A dynamic

IP address

is assigned to a network component automatically by

DHCP

. This

means that the IP address of a network component can change with every login or at

certain intervals.

See also:

Static IP address

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DynDNS

Dynamic DNS

The assignment of

Domain names

and

IP addresses

is handled by the Domain Name

Service (

DNS

). This service is now enhanced with so-called Dynamic DNS (DynDNS) for

Dynamic IP addresses

. This enables the use of a network component with a dynamic IP

address as a

Server

on the Internet. DynDNS ensures that a service can always be

addressed on the

Internet

under the same domain name regardless of the current IP

address.

Encryption

Encryption protects confidential information against unauthorised access. With an

encryption system, data packets can be sent securely over a network. The Gigaset

SE587 WLAN dsl offers

WEP

encryption and

WPA

for secure data transfer over wireless

networks.

Ethernet

Ethernet is a network technology for local networks (

LANs

) defined by the

IEEE

as stand-

ard IEEE 802.3. Ethernet uses a base-band cable with a transfer rate of 10 or 100

Mbps

or 1 Gbps.

Firewall

Firewalls are used by network operators as protection against unauthorised external

access. This involves a whole bundle of hardware and software actions and technolo-

gies that monitor and control the data flow between the private network to be pro-

tected and an unprotected network such as the

Internet

.

See also:

NAT

Flat rate

Flat rate is a particular billing system for

Internet

connections. The

Internet service pro-

vider

charges a monthly fee regardless of the duration and number of logins.

FTP (File Transfer Protocol)

FTP is a protocol for exchanging files on the Internet. You can use it, for example, to

offer files for downloading or to receive files from other users.

Full duplex

Data transfer mode in which data can be sent and received at the same time.

See also:

Half duplex

Gateway

A gateway is a device for connecting networks with completely different architectures

(addressing, protocols, application interfaces etc.). Although it is not totally correct, the

term is also used as a synonym for

Router

.

Global IP address

See

Public IP address

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Half duplex

Operating mode for data transmission. Only one side can send and/or receive data at

the same time.

See also:

Full duplex

HTTP proxy

An HTTP proxy is a

Server

that network components use for their

Internet

traffic. All

requests are sent via the proxy.

Hub

A hub connects several network components in a star-topology network by sending all

the data it receives from one network component to all the other network components.

See also:

Switch

,

Bridge

,

Router

,

Gateway

IEEE

Institute of Electrical and Electronic Engineers

The IEEE is an international body for defining network standards, especially for stand-

ardising

LAN

technologies, transfer protocols, data transfer speeds and wiring.

IEEE 802.11

IEEE

802.11 is a standard for wireless LANs operating in the 2.4 GHz or 5 GHz band. In

the so-called

Infrastructure mode

, terminals can be connected to a base station (

Access

point

) or they can connect with each other spontaneously (

Ad-hoc mode

).

IGMP

Internet Group Management Protocol

IGMP is an Internet

Protocol

that enables an Internet computer to inform neighbouring

routers that it is a member of a multicast group. With multicasting, a computer can send

content on the Internet to several other computers that have registered an interest in

the first computer's content. Multicasting can, for example, be used for multimedia pro-

grams for media streaming to recipients that have set up multicast group membership.

Infrastructure mode

Infrastructure mode is a way of operating wireless local networks (

WLANs

) in which an

Access point

handles the data traffic. Network components cannot establish a direct

connection with each other as is the case in

Ad-hoc mode

.