Computernetworknode
Indatacommunication,aphysicalnetworknodecanbeadatacircuitterminationdevice(DCE),suchasamodem,hub,bridgeorswitch;itcanalsobeaDataterminalequipment(DTE),suchasdigitalmobilephones,printersorhosts(suchasrouters,workstations,orservers).
IfthenetworkinquestionisaLANorWAN,eachLANorWANnode(atleastadatalinklayerdevice)musthaveaMACaddress,generallyeachnetworkcardhasone.Examplesincludecomputers,packetswitches,xDSLmodems(withEthernetinterfaces),andwirelessLANaccesspoints.Notethatthehubconstitutesaphysicalnetworknode,butdoesnotconstituteaLANnetworknode.Thisisbecauseanetworkconnectedbyahubislogicallyabusnetwork.Similarly,arepeaterorPSTNmodem(withaserialinterface)isaphysicalnetworknoderatherthanaLANnode.
IfthenetworkinquestionistheInternetoranIntranet,manyphysicalnetworknodesarehosts(thatis,InternetnodesidentifiedbyIPaddresses).Allhostsarephysicalnetworknodes.However,somedatalinklayerdevices,suchasswitches,bridges,andWLANaccesspointsdonothaveIPhostaddresses(exceptforsometimesmanagementpurposes).ThesedevicesarenotconsideredInternetnodesorhosts,buttheyarephysicalnetworknodesandLANnode.
Telecommunicationsnetworknode
Inafixedtelephonenetwork,anodemaybeapublicorprivatetelephoneexchange,remotehuborcomputer,whichprovidessomeintelligentnetworkservices.Incellularcommunications,switchingpointsanddatabases,suchasbasestationcontrollers,homelocationregisters,gatewayGPRSsupportnodes(GGSN),andGPRSservicesupportnodes(SGSN)areallexamplesofnodes.Cellularnetworkbasestationsarenotconsiderednodesinthiscontext.
Inthecabletelevisionsystem(CATV),thistermhasabroadercontext,usuallyrelatedtofiberopticnodes.Thiscanbedefinedasahomeorofficelocationwithinaspecificgeographicareaservedbyapublicfiberopticreceiver.Anopticalfibernodeisusuallydescribedbythenumberof"homepassing"servedbyaspecificopticalfibernode.
NetworkTopology
NetworkTopologyreferstothespecificarrangementofthemembersthatmakeupthenetwork.Dividedintophysical,thatis,real,orlogical,thatis,virtual.Iftheconnectionstructureoftwonetworksisthesame,wesaythattheirnetworktopologyisthesame,althoughtheirinternalphysicalwiringanddistancebetweennodesmaybedifferent.
See
Endthesystem
Host
Networkhardware
Terminal