Physical network

Definition

Thenetwork"connected"bythecomputerhardwaremediabytheTCPfactoryiscalledthephysicsweb.

Currently,thetransmissioncontrolprotocolInternetprotocolTCP/IPiscommonlyused,thatis,thetransmissionlayerIPcorrespondingtothenetworklayeroftheOSIseven-layermodelcorrespondingtoTCP.Thesetwolayersarecalledlogicalnetworks.ThephysicallayerandthedatalinklayerItiscalledthephysicallayertokeepconsistentwiththeOSIregulations.

Forexample,thePCnetworkthatyoucanseeandtouchthroughnetworkequipmentsuchasnetworkcables,routers,switches,converters,etc.isaphysicalnetwork.Andtheprotocolornetworkstructureusedinthisnetwork,suchasthisnetworkisdividedintomultiplesubnetsormulti-levelrelationships,thesearedividedbylogicalnetworks.

OSIseven-layermodel

OpenSystemInterconnectReferenceModel(OpenSystemInterconnect,referredtoasOSI)isjointlydevelopedbytheInternationalOrganizationforStandardization(ISO)andtheInternationalTelegraphandTelephoneConsultativeCommittee(CCITT)Theopensysteminterconnectionreferencemodelprovidesafunctionalstructureframeworkfortheopeninterconnectioninformationsystem.Itisfromlowtohigh:physicallayer,datalinklayer,networklayer,transportlayer,sessionlayer,presentationlayerandapplicationlayer.