8 Glossar
DSL:
„Digital Subscriber Line“
DSLisatelecommunicationtechnologythatprovidesafast,permanentconnectiontotheInternetbyusing
thetwo-wirecoppercablefoundinalmosteveryhomeandofce.
Eitherthesamerangeisavailableforthetransmissionineachdirection,orhowever-thatisthemore
oftenthecase-thechannelforreceivingdata(Downstream)ismoreefcientthanforsendingdata
(Upstream).ThereareseveraltypesofDSLandxDSLreferstothefamilyofDSLtechnologies:
The most common techniques permit 1.5 to 1.6 Mbps (megabit per second), which is at least 15 times
fasterthananISDNconnection.
ADSL:
„Asymmetric Digital Subscriber Line“
ThemostcommonformofDSLisADSL
Itentailsonehigh-speed,unidirectionaldatachannelandonelow-speed,bidirectionalcontrolchannel(ma-
kingitasynchronous).Basically,thismeansyoucandownloadfasterthanyoucanupload.ADSLsupports
data rates to 8 Mbps when receiving data (known as the downstream rate) and rates up to
1 Mbps when sending data (known as the upstream rate).
LAN:
„Local Area Network“
A local communication network in a relatively small, predetermined area (such as a room, a building, or a set
ofbuildings)consistingofoneormorecomputers(LANServer),workstations,anetworkoperatingsystem,
anuniformprotocolandspecialcablesascommunicationline.
Server:
AserveristhecontrolcomputeronaLAN,meaningitcontrolsthesoftware,accesstoprintersandother
partsofthenetwork.Ithousesinformationandrespondstorequestsforinformation.
Ethernet:
Networkprotocolforlocalnetworks
Ethernetrepresentsthemostcommontechnologyfortheconnectionoflocalnetworks(LANs).
Protocol:
A specification that describes how computers talk to each other on a network. A protocol is an established
methodofexchangingdataovertheInternet.
The most common protocols are : HTTP, IP, POP, PPP, SMTP, TCP/IP
DHCP:
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„Dynamic Host Configuration Protocol“
A protocol that provides a mean to allocate IP address dynamically to computers on a LAN. It eliminates the
need to manually assign permanent IP addresses.
TCP/IP:
„Transmission Control Protocol/Internet Protocol“
TheTCP/IPistheStandard-Internet-Protocol.
TheInternet-Protocol(IP)speciesthetransmissionrouteforthedatapackages.TheTCPprotocol
guaranteesthatallsentbyteswillbereceivedcorrectly.TCP/IPistherefora„routable“protocol.
IP AdDress:
„InternetProtocol“-Address;
A numeric address that is given to computers connected to the Internet.
Gateway:
Asystemfor exchanginginformationacrossnetworksthat areincompatible andusedifferentprotocols.
Basically,agatewayisacombinationofhardwareandsoftwarethatconnectstwodifferenttypesof
networkssothatinformationcangetexchanged.Thehardwaredevices(called„bridges“)andthe
computerprogramsperformthenecessarytranslations.
Subnet Mask:
AnumberusedtoidentifyasubnetworksothatanIPaddresscanbesharedonaLAN.
An IP address has two components, the network address and the host address.
DNS:
The Domain Name System (DNS) helps users to find their way around the Internet. Every computer on the
Internethasauniqueaddress-justlikeatelephonenumber-whichisarathercomplicatedstringofnum-
bers. It is called „IP address.“ But it is hard to remember everyone‘s IP address. The DNS makes it
easierbyallowingafamiliarstringofletters(the„domainname“)tobeusedinsteadofthearcane
IP address.
PPP:
„Point to Point Protocol“
ThePPPisadatatransmissionprotocolintheinternet,whichisusedformodem-connections.
PPPoE:
„PPP over Ethernet“
PPPoEistheuseofthenetworkprotocolPPPoveranEthernet-connection.PPPoEisneededtodayforthe
useofanADSLconnection(speciallyinGermany).
PPTP:
„Point to Point Tunneling Protocol“
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