Today,computerscommunicate with each otherso intenesivelyand almostconstantly that wecannot evenimaginewhatwould we dowithoutnetworks:dietwithoutInternet - onlywith papermail andchatexclusivelyoff line?In Computer Communications will try toshed light on thebackgroundof communications services,which are todayused even by younger teens and modern granmas.Whathappens when youwriteinyour browser the address A whole army ofprocesses wakes up, computersand othernetwork devicesbegin to calleach other hastily andask:Doyou knowwho isGoogle,what is itsIPaddress andhow to get toit?Or, at least,who might know this?Well, since we manage to googledaily, the processesobviouslyknow the answers.Justasthey canagree on how toto deliver an e-mail to your colleaguein New Zealandorfind himonSkype,even thoughhe waslast weekin Alaska.In Computer Communications course, however,we will notonly talk about services.We will investigatewhy thenetworkdoes notbecome congested,what are theprotocolsand protocolobligationsof their majesties - computers,why they can communicateboth on wires or without them.We will not ignorethe dangersof theinformationhighways: a few notoriousattackswill be analyzed indetail, whilewe will also describeacomputerizedversionof seat belts andairbags,so that wealllive to seethe end ofthe semesteralive and well, but richerfor an interestingexperience.