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Data and information technology - OBO Bettermann

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Network topologies <strong>and</strong> connection typesRing networkIn a ring network, every workstationis connected to precisely onepredecessor <strong>and</strong> one successorvia a ring-shaped network. If onestation fails, the entire networkfails. Ring networks are used inWLAN applications <strong>and</strong> TokenRing applications.02 TBS-Katalog_2010_Neuer_St<strong>and</strong> / en / 30/03/2010 (LLExport_00986)Telephone systemsIn many cases, modern telephonesystems also act as interfaces fora number of different data services,e.g. the Internet. Many terminaldevices that enable this accessare connected into the lines themselves<strong>and</strong> must be integrated intothe surge protection concept accordingly.As there are now a numberof different systems, these devicesmust have selective protection.There are three distinctly differentessential systems:St<strong>and</strong>ard analogue connectionUnlike other systems, the st<strong>and</strong>ardanalogue connection offers no additionalservices. One or severaltelephones are wired in a starshape<strong>and</strong> ring simultaneouslywhen a call comes in. Access tothe Internet is via a separate modem.Because the analogue connectionwithout technical accessoriesprovides only one channel,the Internet cannot be accessedwhile telephoning <strong>and</strong> likewise, notelephone call is possible whilesurfing.ISDN (Integrated Services DigitalNetwork System)In contrast to the analogue connection,ISDN allows two conversationsto take place at the sametime via a special bus system (S0bus), which provides two channels.This enables the user to surf onthe Internet while telephoning <strong>and</strong>at higher data rates than is possiblewith the analogue connection(64 kBit/s over one channel).ISDN also offers other servicessuch as call-waiting, call-back, etc.DSL system (Digital SubscriberLine)Today, the most commonly usedsystem is the DSL system. SpeechThe number of wires varies according to the network type. 1 = Server, 2 = Ground floor, 3 = 1stfloor<strong>and</strong> data channels are separatedby splitters <strong>and</strong> the data channel isrouted to a special modem(NTBBA), which is connected tothe PC via a network card. DSLdata rates are higher than those ofanalogue <strong>and</strong> ISDN systems <strong>and</strong>therefore enable fast downloadingof music <strong>and</strong> films from the Internet.Because there are a numberof different DSL versions such asA-DSL <strong>and</strong> S-DSL, the general DSLis also designated X-DSL. X-DSLpermits the use of analogue telephoneswithout additional hardware,as well as a combinationwith ISDN.Planning aid, surge protection of data <strong>and</strong> <strong>information</strong> <strong>technology</strong>TBS<strong>OBO</strong>43

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