Introduction
TCP/IPtransmissionprotocol,namelytransmissioncontrol/networkprotocol,alsoknownasnetworkcommunicationprotocol.Itisthemostbasiccommunicationprotocolintheuseofthenetwork.TheTCP/IPtransmissionprotocolstipulatesthestandardsandmethodsforcommunicationbetweenvariouspartsoftheInternet.Inaddition,theTCP/IPtransmissionprotocolistwoimportantprotocolstoensurethetimelyandcompletetransmissionofnetworkdatainformation.TheTCP/IPtransportprotocolisstrictlyafour-layerarchitecture,includingtheapplicationlayer,transportlayer,networklayer,anddatalinklayer.
TCP/IPprotocolisthemostbasicprotocoloftheInternet.ThemainprotocolsoftheapplicationlayerareTelnet,FTP,SMTP,etc.,whichareusedtoreceivedatafromthetransportlayerortransferdataaccordingtodifferentapplicationrequirementsandmethods.Transmissiontothetransportlayer;themainprotocolsofthetransportlayerareUDPandTCP,whicharethechannelsforuserstousetheplatformandtheinternaldataofthecomputerinformationnetwork,whichcanrealizedatatransmissionanddatasharing;themainprotocolsofthenetworklayerareICMP,IP,IGMP,Mainlyresponsibleforthetransmissionofdatapacketsinthenetwork;andthenetworkaccesslayer,alsocalledthenetworkinterfacelayerorthedatalinklayer,themainprotocolsareARP,RARP,andthemainfunctionistoprovidelinkmanagementerrordetectionandinformationaboutdifferentcommunicationmediaEffectivehandlingofdetailedissues,etc.
>Background
ThepredecessoroftheInternetnetworkARPANETdidnotuseTransmissionControlProtocol/InternetProtocol(TransmissionControlProtocol/InternetProtocol,TCP/IP),butanetworkprotocolcalledNetworkControlProtocol(NetworkControlProtocol,NCP),butwiththedevelopmentofthenetworkandthecontinuousimprovementofusers’demandsonthenetwork,designershavediscoveredthattheNCPprotocolhasmanyshortcomings.AsfortheinabilitytofullysupporttheARPANETnetwork,especiallytheNCPcanonlybeusedinahomogeneousenvironment(theso-calledhomogeneousenvironmentisthatallcomputersonthenetworkrunthesameoperatingsystem),thedesignerbelievesthattherestrictionof"homogeneity"shouldnotbeBeaddedtoawidelydistributednetwork.In1980,theTCP/IPprotocolusedinthe"heterogeneous"networkenvironmentwassuccessfullydeveloped,thatistosay,theTCP/IPprotocolcanachieveinteroperabilityonvarioushardwareandoperatingsystems.In1982,ARPANETbegantoadopttheTCP/IPprotocol.
Generationprocess
(1)In1973,KahnandCerfdevelopedthetwomostcoreprotocolsintheTCP/IPprotocol:TCPprotocolandIPprotocol.
(2)InDecember1974,KahnandCerfformallypublishedtheTCP/IPprotocolandexplaineditindetail.Atthesametime,inordertoverifytheavailabilityoftheTCP/IPprotocol,adatapacketissentfromoneendandarrivesattheserverafterajourneyofnearly100,000km.Inthistransmission,thedatapacketdidnotloseabyte,whichfullydemonstratedthesuccessoftheTCP/IPprotocol.
(3)OnNewYear'sDayin1983,theTCP/IPprotocolofficiallyreplacedtheNCP.Sincethen,TCP/IPhasbecomeanetworkrulethatmostoftheInternetcomplieswith.
(4)In1984,theTCP/IPprotocolwasaffirmedbytheUSDepartmentofDefenseandbecameastandardthatmostcomputerscompliedwith.
(5)OnSeptember9,2005,KahnandCerfwereawardedthePresidentialMedalofFreedomfortheiroutstandingcontributionstoAmericanculture.
ThecompositionoftheTCP/IPprotocol
TheTCP/IPprotocolreferstotheOSIarchitecturetoacertainextent.TheOSImodelhassevenlayers,frombottomtotoptheyarethephysicallayer,thedatalinklayer,thenetworklayer,thetransportlayer,thesessionlayer,thepresentationlayer,andtheapplicationlayer.Butthisisobviouslyabitcomplicated,sointheTCP/IPprotocol,theyaresimplifiedintofourlevels.
(1)Theservicesprovidedbytheapplicationlayer,presentationlayer,andsessionlayerarenotverydifferent,sointheTCP/IPprotocol,theyarecombinedintoonelayeroftheapplicationlayer.
(2)Sincethetransportlayerandthenetworklayerplayanimportantroleinthenetworkprotocol,theyaretreatedastwoindependentlayersintheTCP/IPprotocol.
(3)Becausethecontentofthedatalinklayerandthephysicallayeraresimilar,theyaremergedintoalayerofthenetworkinterfacelayerintheTCP/IPprotocol.TheTCP/IPprotocolwithonlyafour-layerarchitectureismuchsimplerthantheOSIwithaseven-layerarchitecture.ItispreciselythiswaythattheTCP/IPprotocolismoreefficientandlowerinactualapplications.
IntroducethefourlevelsintheTCP/IPprotocolrespectively.
Applicationlayer:TheapplicationlayeristhefirstlayeroftheTCP/IPprotocol,whichdirectlyprovidesservicesfortheapplicationprocess.
(1)Fordifferenttypesofapplications,theywillusedifferentprotocolsattheapplicationlayeraccordingtotheirneeds.ThemailtransmissionapplicationusestheSMTPprotocol,theWorldWideWebapplicationusestheHTTPprotocol,andtheremoteloginserviceapplicationusesThereisaTELNETprotocol.
(2)Theapplicationlayercanalsoencrypt,decrypt,andformatdata.
(3)Theapplicationlayercanestablishordisconnectwithothernodes,whichcanfullysavenetworkresources.
Transportlayer:AsthesecondlayeroftheTCP/IPprotocol,thetransportlayerplaysamainroleintheentireTCP/IPprotocol.Andinthetransportlayer,TCPandUDPalsoplaytheroleofmainstay.
Networklayer:ThenetworklayerislocatedatthethirdlayerintheTCP/IPprotocol.IntheTCP/IPprotocol,thenetworklayercanperformfunctionssuchastheestablishmentandterminationofnetworkconnectionsandthesearchforIPaddresses.
Networkinterfacelayer:IntheTCP/IPprotocol,thenetworkinterfacelayerislocatedatthefourthlayer.Sincethenetworkinterfacelayercombinesthephysicallayerandthedatalinklayer,thenetworkinterfacelayerisnotonlyaphysicalmediumfordatatransmission,butalsoanaccurateanderror-freelineforthenetworklayer.
Features
TCP/IPprotocolcandeveloprapidlyandbecomethedefactostandard,becauseitjustadaptstotheneedsofdatacommunicationworldwide.Ithasthefollowingcharacteristics:
(1)Theprotocolstandardiscompletelyopen,canbeusedbyusersforfree,andisindependentofspecificcomputerhardwareandoperatingsystems.
(2)Itisindependentofthenetworkhardwaresystemandcanrunonthewideareanetwork,whichismoresuitablefortheInternet.
(3)Uniformdistributionofnetworkaddresses,eachdeviceandterminalinthenetworkhasauniqueaddress.
(4)High-levelprotocolstandardizationcanprovideavarietyofreliablenetworkservices.
Communicationprocessandrelatedprotocols
Intheprocessofnetworkcommunication,thehostsendingdataiscalledthesourcehost,andthehostreceivingthedataiscalledthedestinationhost.Whenthesourcehostsendsdata,thedataistransferredfromtheupperlayertothelowerlayerinthesourcehost.Theapplicationprocessinthesourcehostfirsthandsthedatatotheapplicationlayer,andtheapplicationlayeraddsnecessarycontrolinformationtoformamessagestream,whichispasseddowntothetransportlayer.Thetransportlayeraddsthecontrolinformationofthislayertothereceiveddataunittoformmessagesegmentsanddatagrams,whicharethenhandedovertotheInternetlayer.TheInternetlayeraddsthecontrolinformationofthislayertoformanIPdatagram,whichispassedtothenetworkinterfacelayer.ThenetworkinterfacelayerassemblestheIPdatagramshandedoverfromtheInternetlayerintoframes,andtransmitsthemtothenetworkhardware(ie,thephysicallayer)intheformofbitstreams,andthedataleavesthesourcehost.
Linklayer
TheEthernetprotocolstipulatesthatalldevicesconnectedtothenetworkmustbeequippedwithanetworkadapter,thatis,anetworkcard,anddatapacketsmustbetransmittedfromonenetworkcardtoanother.Thenetworkcardaddressisthesendingaddressandreceivingaddressofthedatapacket.WiththeMACaddress,theEthernetadoptsabroadcastformtosendthedatapackettoallhostsinthesubnet.Aftereachhostinthesubnetreceivesthispacket,WillreadthetargetMACaddressintheheader,andthencomparewithitsownMACaddress,iftheyarethesame,dothenextstep,iftheyaredifferent,discardthepacket.
Sothemainjobofthelinklayeristogroupelectricalsignalsandformdataframeswithspecificmeanings,andthensendthemtothereceiverthroughphysicalmediaintheformofbroadcast.
Networklayer
IPprotocol
ThenetworklayerintroducedtheIPprotocolanddevelopedasetofnewaddresses,allowingustodistinguishWhethertwohostsbelongtothesamenetwork,thissetofaddressesisthenetworkaddress,whichistheso-calledIPaddress.TheIPprotocoldividesthis32-bitaddressintotwoparts.Thefirstpartrepresentsthenetworkaddress,andthebackpartrepresentstheaddressofthehostinthelocalareanetwork.IftwoIPaddressesareinthesamesubnet,thenetworkaddressesmustbethesame.InordertodeterminethenetworkaddressintheIPaddress,theIPprotocolalsointroducesasubnetmask.TheIPaddressandthesubnetmaskcangetthenetworkaddressafterbitwiseANDoperation.
ARPprotocol
TheaddressresolutionprotocolisanetworklayerprotocolthatobtainstheMACaddressbasedontheIPaddress.Itsworkingprincipleisasfollows:ARPwillfirstinitiatearequestpacket,theheaderofthepacketcontainstheIPaddressofthetargethost,andthenthepacketwillberepackagedatthelinklayertogenerateanEthernetpacket,whichisfinallybroadcastbytheEthernetForallhostsinthesubnet,eachhostwillreceivethispacketandtakeouttheIPaddressintheheader,andcompareitwithitsownIPaddress.Ifitisthesame,itwillreturnitsownMACaddress.Ifitisdifferent,itwillbediscarded.Thepacket.ARPreceivesthereturnmessagetodeterminetheMACaddressofthetargetmachine;atthesametime,ARPwillalsostorethereturnedMACaddressandthecorrespondingIPaddressinthelocalARPcacheforacertainperiodoftime,anddirectlyqueryARPwhenrequestednexttimeCachetosaveresources.
RoutingProtocol
FirstlyusetheIPprotocoltodeterminewhetherthetwohostsareinthesamesubnet,andiftheyareinthesamesubnet,usetheARPprotocoltoqueryCorrespondingMACaddress,andthensenddatapacketstohostsinthissubnetintheformofbroadcast;iftheyarenotinthesamesubnet,Ethernetwillforwardthedatapackettothegatewayofthissubnetforrouting.ThegatewayisthebridgebetweenthesubnetandthesubnetontheInternet,sothegatewaywillforwardmultipletimes,andfinallyforwardthedatapackettothesubnetwherethetargetIPislocated,andthenobtainthetargetmachineMACthroughARP,andfinallythroughbroadcastTheformsendsthedatapackettothereceiver.Thephysicaldevicethatcompletesthisroutingprotocolistherouter.Therouterplaystheroleofatraffichub.Itwillselectandsetarouteaccordingtothechannelconditions,andusethebestpathtoforwarddatapackets.
So,themainworkofthenetworklayeristodefinenetworkaddresses,distinguishnetworksegments,MACaddressinginsubnets,androutedatapacketsofdifferentsubnets.
Transportlayer
Thelinklayerdefinestheidentityofthehost,thatis,theMACaddress,whilethenetworklayerdefinestheIPaddressandclarifiesthenetworksegmentwherethehostislocated.WiththesetwoAddress,datapacketscanbesentfromonehosttoanother.Butinfact,thedatapacketissentfromacertainapplicationofahost,andthenreceivedbytheapplicationoftheotherhost.Andeachcomputermayberunningmanyapplicationsatthesametime,sowhenthedatapacketissenttothehost,itisimpossibletodeterminewhichapplicationwillreceivethepacket.Therefore,thetransportlayerintroducedtheUDPprotocoltosolvethisproblem,inordertoidentifytheidentityofeachapplication.
UDPprotocol
UDPprotocoldefinestheport,eachapplicationonthesamehostneedstospecifyauniqueportnumber,andstipulatethenetworkTheportinformationmustbeaddedtothetransmitteddatapacket.Whenthedatapacketarrivesatthehost,thecorrespondingapplicationcanbefoundaccordingtotheportnumber.TheUDPprotocolisrelativelysimpleandeasytoimplement,butithasnoconfirmationmechanism.Onceadatapacketissent,itisimpossibletoknowwhethertheotherpartyhasreceivedit,soitsreliabilityispoor.Inordertosolvethisproblemandimprovenetworkreliability,theTCPprotocolwasborn.
TCPprotocol
TCPstandsforTransmissionControlProtocol,whichisaconnection-oriented,reliable,bytestream-basedcommunicationprotocol.Toputitsimply,TCPisaUDPprotocolwithanacknowledgmentmechanism.Itrequiresacknowledgmenteverytimeadatapacketissent.Ifadatapacketislost,theacknowledgmentcannotbereceived,andthesendermustresendthedatapacket.Inordertoensurethereliabilityoftransmission,theTCPprotocolestablishesathree-conversationconfirmationmechanismonthebasisofUDP,thatis,areliableconnectionmustbeestablishedwiththeotherpartybeforeofficiallysendingandreceivingdata.LikeUDP,TCPdatapacketsarecomposedoftwoparts:headeranddata.TheonlydifferenceisthatTCPdatapacketshavenolengthlimitandcanbeinfiniteintheory.However,inordertoensuretheefficiencyofthenetwork,usuallythelengthofTCPdatapacketsisnotExceedthelengthoftheIPdatapackettoensurethatasingleTCPdatapacketdoesnothavetobesplit.
Themainworkofthetransportlayeristodefineports,identifyapplicationprograms,andimplementport-to-portcommunication.TheTCPprotocolcanensurethereliabilityofdatatransmission.
Applicationlayer
Intheory,withthesupportoftheabovethree-layerprotocol,datacanalreadybetransferredfromanapplicationononehosttoanapplicationonanotherhost.Butthedatatransmittedatthistimeisabytestream,whichcannotbewellrecognizedbytheprogramandhaspooroperability.Therefore,theapplicationlayerdefinesavarietyofprotocolstostandardizethedataformat,suchashttp,ftp,smtp,etc.,Intherequestheader,therequestdataformatAcceptandtheresponsedataformatContent-Typearerespectivelydefined.Withthisspecification,whentheotherpartyreceivestherequest,itwillknowwhatformattousetoparse,thenprocesstherequest,andfinallyfollowtherequestThedataisreturnedintheformatrequiredbytheparty,andaftertherequesterreceivestheresponse,itwillinterpretitintheprescribedformat.
Sothemainjoboftheapplicationlayeristodefinethedataformatandinterpretthedataaccordingtothecorrespondingformat.
Securityrisks
Attacksonthelinklayer
InTCP/IPnetworks,thelinklayerhasthehighestlevelofcomplexity.ThemostcommonattackmethodisusuallytheTCP/IPprotocolEthernetcomposedofnetworksniffing.Atpresent,themostwidelyusedlocalareanetworkinmycountryisEthernet,anditssharedchannelutilizationrateisveryhigh.TheEthernetcardhastwomainworkingmodes,oneisthegeneralworkingmode,andtheotheristhemorespecialhybridmode.Inthiscase,informationlossislikelyduetothereasonoftheattack,andtheattackercanobtainkeydatainformationsuchasaccountsandpasswordsthroughdataanalysis.
Attacksonthenetworklayer
ARPspoofing
ARP(AddressResolutionProtocol)isamethodofobtainingphysicaladdressesbasedonIPaddressesTCP/IPprotocol.Undernormalcircumstances,therewillbeasubnetormultiplesubnethostsintheprocessofsendingIPpacketstousethefirstlayerofthenetworklevel,andARPactsasthefirstquerytoolforthesourcehost,andthephysicaladdresscorrespondingtotheIPaddressisnotfound.Atthetime,thephysicaladdressinformationrelatedtothehostandtheIPaddressissenttothehost.Atthesametime,thesourcehostsendsaresponseincludingitsownIPaddressandARPinspectiontothedestinationhost.IfARPrecognizesthelinkerror,thenARPdirectlyappliesthesuspiciousinformation,thenthesuspiciousinformationwilleasilyenterthetargethost.TheARPprotocolhasnostate.ThehostwillautomaticallycacheanyreceivedARPsregardlessofwhetheritreceivesarequest.Iftheinformationcontainsviruses,theuseofARPspoofingwillcausethesecurityofnetworkinformationtobeleaked.Therefore,intheARPidentificationlink,protectionshouldbeincreased,andmoreidentificationbarriersshouldbeestablished.TheidentificationcannotonlybedonebyIPname,butalsotherelatednatureofIPshouldbefullyreferenced.
ICMPspoofing
TheICMPprotocolisalsoanInternetcontrolmessageprotocol,whichismainlyusedtotransfercontrolinformationbetweenthehostandtherouter.Throughthisprotocol,informationsuchaswhetherthenetworkisunblocked,whetherthehostisreachable,andwhethertherouteisavailablecanbecontrolled.Onceanerroroccurs,thedatapacketwillbesentinstantlybythehost,andtheinformationdescribingtheerrorwillbeautomaticallyreturned.Thisprotocolisaveryimportantprotocolinnetworksecurity.However,duetoitsowncharacteristics,itisextremelyvulnerabletointrusion.Generallyspeaking,whenthetargethostsendsalargenumberofICMPdatapacketsforalongtime,thetargethostwilloccupyalargeamountofCPUresourcesandeventuallycausethesystemtobeparalyzed.
Attacksonthetransportlayer
Therearealsonetworksecurityissuesatthetransportlayer.Forexample,inthefieldofnetworksecurity,IPspoofingisaneffectivemeanstohideoneself,mainlybyforgingone'sownIPaddressandsendingmaliciousrequeststothetargethosttoattackthehost,butthehostcannotbeaccuratelyconfirmedbecausetheIPaddressishiddenThesourceoftheattack.Ortaketheopportunitytostealrelevantconfidentialinformationbygainingthetrustofthetargethost.IPspoofingisoftenusedinDOSattacks.Thisisbecausethesourceofdatapacketsisrelativelywideandcannotbeeffectivelyfiltered,whichgreatlyreducestheeffectivenessofIPbasicdefense.Inaddition,intheICMPtransmissionchannel,becauseICMPisoneofthecomponentsoftheIPlayer,anyportintheIPsoftwaresendsaPINGfiletoICMP,whichisusedasanapplication,andICMPwillrespondifthefiletransferisallowed.,Thiscommandcancheckthelegitimacyofthemessage.Alldataappliedfortransmissionwillbasicallyagreetothetransmissionlayer.ThemainreasonforthisisthatthePINGsoftwareprogrammingcannotintelligentlyidentifymaliciousinformation.Generally,networksecurityprotectionsystemsandfirewallswillautomaticallydefaulttotheexistenceofPING,therebyignoringthepossibleconsequences.SecurityRisk.
Attacksattheapplicationlayer
FortheInternet,IPaddressesanddomainnamesareinone-to-onecorrespondence,andtheconversionbetweenthetwoiscalleddomainnameresolution.TheDNSistheserverfordomainnameresolution.DNSspoofingreferstothebehaviorofanattackerpretendingtobeadomainnameserver.UsingDNSspoofingcanprovidewrongDNSinformationtothetargethost.Therefore,DNSspoofingcanmisleadusersintoillegalserversandmakeusersbelievethattheIPisfraudulent.Inaddition,theinterfaceonthePTPnetworkreceivesdatathatdoesnotbelongtothehost.Thisisalsoasecurityproblemattheapplicationlayer.SomeTrojanhorsevirusescantakeadvantageoftheopportunitytoinvadeandcausedataleakage,therebycausingnetworksecurityproblems.
SecurityStrategy
FirewallTechnology
Thecoreoffirewalltechnologyistoconstructarelativelysafesubnetenvironmentinaninsecurenetworkenvironmenttoensuretheinternalnetworksecurity.Itcanbethoughtofasaswitchthatblocksandallowsinput,whichmeansthatfirewalltechnologycanallowresourceswithaccessrightstopassthrough,anddenyothercommunicationdatawithoutrights.Whenthefilteriscalled,itwillbetransferredtothekernelforexecution.,Andwhentheserviceisstopped,thefilteringruleswillbeeliminatedfromthekernel,andallpacketfilteringfunctionsinthekernelrundeepinthestack.Atthesametime,thereareproxyservicefirewalls,whicharecharacterizedbycompletelyisolatingthedirectcommunicationbetweentheinternalnetworkandtheexternalnetwork.Theinternalnetworkaccesstotheexternalnetworkistransformedintotheproxyfirewall’sexternalnetworkaccess,andthenforwardedtotheinternalnetwork.Whentheproxyserverfindssignsofbeingattacked,itwillkeepthetracesoftheattackandpromptlywarnthenetworkadministrator.
Intrusiondetectionsystem
Intrusiondetectionsystemisanetworksecuritytechnologythathasemergedinrecentyears.Thistechnologyisadynamicsecuritytechnology.Throughtheresearchonthecharacteristicsofintrusionbehaviorandtheintrusionprocess,thesecuritysystemimmediatelyrespondsinrealtime,andgraduallyinterceptsandprotectsitbeforetheattackerhascompletedit.Theintrusionmonitoringsystemisalsoanimportantcontentintheresearchofnetworksecurityissues.Withthehelpofthistechnology,logiccompensationfirewalltechnologycanberealized,whichcanpreventinternalintrusions,misoperationsandexternalintrusionsinrealtime.Italsohasareal-timealarmfunction,whichaddstothenetworksecurityprotection.Aprotectivenet.Intrusiondetectiontechnologyhasthreedevelopmentaspects:intelligentintrusiondetection,comprehensivesecuritydefenseplananddistributedintrusiondetection.
Accesscontrolstrategy
Accesscontrolisthemainstrategytoprotectandpreventnetworksecurity.Sinceeachsystemwantstoaccessusers,theymusthaveaccessrights,andonlythosewithlocationrightscanallowaccess.Suchamechanismiscalledaccesscontrol.Thissecuritydefensestrategyisnotachievedbydirectlyresistingintrusions,butitisanimportantstrategyforactualnetworkprotection,anditisalsoanurgentneedforusers.Itmainlyincludestwoaspectsoffunctions.Oneistocheckthelegalityoftheexternallocation,whichissimilartoafirewall,andtheotheristochecksometargetsitesforaccessfromtheinsidetotheoutside,blockillegalsites,andontheserver.,Youcanrestrictaccesstoservicesforthoseusers.
Timelinessresearch
ThetimelinessoftheTCP/IPtransmissionprotocolmeansthatthetransmittedinformationisvaluabletouserswithinacertainusescenarioandtimerange..Moregenerally,thetimelinessofinformationalsoincludestheinterestofrecipientsandtheimpactonsocietythatdataandinformationarouseaftertransmission.Butastimegoesby,thevalueofdatainformationwillbelessandlessutilized.Inotherwords,relateddatainformationforthesamethinghasalargeorsmallvaluedifferenceindifferenttimeperiods.Thisdifferenceiscalledthetimelinessofdatainformation.DatainformationtransmissionundertheTCP/IPtransmissionprotocolovercomesthelag,delay,andlowefficiencyoftraditionalinformationtransmissionmethods.TheTCP/IPtransmissionprotocolcanoftentransmiteffectiveinformationtothosewhoneeditinatimelymanner,whichcanmaximizethevalueofdatainformationandensurethetimelinessofdatainformation.
Up-to-datenessofdata
Withthehigh-speedoperationofmodernsociety,theamountofdatainformationreceivedbypeoplehasexploded,butthequalityofdatainformationisuneven.Therefore,peopletendtoforgettheinformationtheyreceiveovertime.Generaleventinformationmayloseitsvalidityinashortperiodoftime.Therefore,time-sensitivedatainformationmusthavethecharacteristicsofnewnessandcankeeppacewiththetimes.However,thetimelinessoftheTCP/IPtransmissionprotocolinthecomputernetworkjusthasthecharacteristicsoftimeliness.Itcanusehigh-speednetworktechnologytocapturescientificandeffectivedatainformationintime.Andastimechanges,outdateduselessinformationcanbeautomaticallyeliminated,soastokeeppacewiththetimes.
Dataflexibility
Afterdataistransmitted,itisultimatelytomeettheneedsofusers.TheTCP/IPtransmissionprotocolinthecomputernetworkcannotonlyguaranteetheup-to-datenessofdatainformation,butcanalsoprovidedatainformationthatmatchestheactualsituationaccordingtothedifferentneedsofusers,withfullflexibilityandscalability.
Datasecurityandaccuracy
Datainformationisgenerallyaffectedbythetransmitter,receiver,transmissionchannel,andexternalenvironmentduringthetransmissionprocess.Thesefactorswillaffectthetimelinessofdatainformationtransmissiontovaryingdegrees.Forexample,duetothelimitedlevelofthetransmitter’sowncomputerexpertise,failuretorealizetheimportanceofinformationtransmission,insufficientdatacollectionandinefficiency,ortheuseofthewrongtransmissionmethod,itwillaffectthetimelinessofinformationtransmission.ThedatatransmissionoftheTCP/IPtransmissionprotocolinthecomputernetworkcannotonlyhandlethecomplexinformationstructureandalargenumberofdatainformation,butalsomaintainthesecurityofthedatainformationandensurethescientificaccuracyofthedatainformation.
Thefluencyofthedatatransmissionprocess
Inordertomeettheneedsoftoday’ssocietyfordatainformation,theTCP/IPtransmissionprotocolinthecomputernetworkhasimprovedthetraditionaldatatransmissionprocess.Makesthetransmissionofnetworkinformationtime-sensitive,fasterandmoreconvenient.BasedontheTCP/IPprotocolofthecomputernetwork,thedatatransmissionprocessismainlytoestablishthethreemainlinksofTCP/IPconnection,datatransmission,anddatareception.Theseamlessconnectionofthesethreelinksenablesreal-timetransmissionofdatainformation.InthecommunicationoftheTCP/IPtransmissionprotocol,inordertoensurethatthedatainformationreachesthedestinationaddress,thedatasendingportandthedatareceivingportneedtosendinformationtobothpartiestoconfirmwhetheracommunicationconnectioncanbeestablished.EstablishingaTCP/IPconnectionstationportisaprerequisitefordatainformationtransmission.AftertheTCP/IPconnectionstationportisestablished,datainformationcanbesent.Thedatainformationfirstentersthetransmissionlayerofthesendingbuffer,andthenistransmittedlayerbylayer.Intheprocessofsending,thetransportlayerprotocolwillencapsulatethedatainformationaccordinglyinordertoachievecompleteandaccuratetransmission.Thereceptionofdatainformationismainlytoreceivethecontrolcommandsofthedatatransmissioncircuitboardsentbythecomputer.Afterthedestinationhostreceivesthedatapacket,itwillfirstidentifyit,determinewhethertheeffectivecarrierofthedatapacketisIP,ARPorRARP,andthenperformcorrespondingdatadecapsulationprocessing.Finally,thedatainformationissenttotherequiredapplication.Thethreelinksintheprocessofdatainformationtransmissionareinterlocked,realizingthetimelinessoftheTCP/IPtransmissionprotocolbasedonthecomputernetwork.
Advancedeaseofuseoftransmissiontechnology
Themostimportantthingtorealizereal-timeinformationtransmissionisthesupportofnetworktechnology.TheTCP/IPtransmissionprotocolcanguaranteethetimelytransmissionofdatainformation.Thetechnologyitusesisadvancedandeasytounderstandanduse.TheTCP/IPtransmissionprotocolinthecomputernetworkmainlyusesadvanceddatacompressiontechnology.Datacompressionistheprocessoftextencodinginordertostorethesamedatainlessbytespace.Thespaceoccupiedbythetextisreducedandthetransmissionspeedisincreased.Datacompressiontechnologyallowsreal-timeencodingatthefastestoperatingspeed.
Defects
LiketheOSlmodel,theTCP/IPmodelandprotocolalsohavetheirownproblems.
(1)Themodeldoesnotclearlydistinguishtheconceptsofservices,interfaces,andprotocols.Therefore,theTCP/IPmodelisnotagoodtemplateforusingnewtechnologiestodesignnewnetworks.
(2)TheTCP/IPmodelisnotuniversalatall,anditisnotsuitablefordescribinganyprotocolstackotherthantheTCP/IPmodel.
(3)Thelinklayerisnotalayerintheusualsense.Itisaninterfacebetweenthenetworklayerandthedatalinklayer.Thedistinctionbetweeninterfacesandlayersisveryimportant.
(4)TheTCP/IPmodeldoesnotdistinguishbetweenthephysicallayerandthedatalinklayer.Thetwolayersarecompletelydifferent.Thephysicallayermustdealwiththetransmissioncharacteristicsofcoppercables,opticalfibers,andwirelesscommunications;whilethedatalinklayer'sjobistodeterminethestartandendoftheframe,andsendtheframefromoneendtotheotheraccordingtotherequireddegreeofreliability.Oneend.