Introduction to networking
Section_ 3
E.M.A
Medium
MediumAccessAccessControlControl(MAC),(MAC),alsoalsoknownknownasasMediaMediaAccessAccessControl,Control,isisaasetsetofofrulesrulesandandproceduresproceduresthatthatgoverngovernhowhowmultiplemultipledevicesdevicesshareshareaasinglesinglesharedsharedtransmissiontransmissionmediummediumininaanetworknetwork..It'sIt'saacrucialcrucialcomponentcomponentofofthethedatadatalinklinklayerlayer(Layer(Layer22))ofofthetheOSIOSImodelmodel..?Function:Function:Packages data into frames, adds error detection and correction mechanisms (like checksums), Packages data into frames, adds error detection and correction mechanisms (like checksums), and controls access to the physical medium using protocols like Carrier Sense Multiple Access with and controls access to the physical medium using protocols like Carrier Sense Multiple Access with Collision Detection (CSMA/CD).Collision Detection (CSMA/CD).?ProtocolsProtocols::DefinesDefinesthetheelectrical,electrical,mechanical,mechanical,andandoperationaloperationalspecificationsspecificationsforfortransmittingtransmittingdata,data,includingincludingvoltagevoltagelevels,levels,cablecablepinouts,pinouts,andandsignalsignalencoding/decodingencoding/decoding..?CarrierCarrierSenseSenseMultipleMultipleAccessAccesswithwithCollisionCollisionAvoidanceAvoidance(CSMA/CA)(CSMA/CA)::UsedUsedininWiWi--FiFiandandotherotherwirelesswirelessnetworks,networks,wherewheredevicesdevicesavoidavoidcollisionscollisionsbybysendingsendingaarequestrequesttototransmittransmit(RTS)(RTS)beforebeforesendingsendingdatadataandandwaitingwaitingforforaaclearcleartotosendsend(CTS)(CTS)responseresponse..?TransmissionTransmissionControlControlProtocolProtocol((TCPTCP)): TCPTCPisisaaconnectionconnection--orientatedorientatedprotocolprotocolthatthatoffersoffersgreatergreaterreliabilityreliabilitywhenwhenititcomescomestototransportingtransportingdatadatathanthanwhatwhatUDPUDPprovidesprovides..WithWithTCP,TCP,thetheapplicationapplicationwhichwhichsendssendsthethedatadatareceivesreceivesacknowledgmentacknowledgmentororverificationverificationthatthatthethedatadatawaswasactuallyactuallyreceivedreceived..ItItisisusedusedforformanymanyprotocols,protocols,includingincludingHTTPHTTPwebwebbrowsingbrowsingandandemailemailtransfertransferwherewherelosslesslosslessdatadatatransfertransferisisimportantimportant..IndividualIndividualunitsunitsofofdatadatatransmissiontransmissionininthetheTCPTCPprotocolprotocolarearereferredreferredtotoasassegmentssegments..?Protocols:Protocols:Ethernet, WiEthernet, Wi--Fi (IEEE Fi (IEEE 802.11802.11), Frame Relay, Point), Frame Relay, Point--toto--Point Protocol (PPP).Point Protocol (PPP).?UserUserDatagramDatagramProtocolProtocol((UDPUDP))::UDPUDPisisaaconnectionlessconnectionlessprotocolprotocolthatthatdoesdoesnotnotprovideprovidereliablereliabledatadatatransporttransport..NoNoacknowledgmentsacknowledgmentsarearetransmittedtransmitted..ThisThisprotocolprotocolgivesgivesaahigherhigherthroughputthroughputandandshortershorterlatencylatencyandandisisoftenoftenusedusedforformulticasting,multicasting,broadcastingbroadcastingandandrealreal--timetimemultimediamultimediacommunicationcommunicationwherewhereoccasionaloccasionalpacketpacketlosslossisisacceptableacceptable..MessagesMessagessentsentwithwithUDPUDParearereferredreferredtotoasasdatagramsdatagrams..The OSI
The OSI 77--layers modellayers model
The
TheOSIOSImodel,model,alsoalsoknownknownasasthetheOpenOpenSystemsSystemsInterconnectionInterconnectionmodel,model,isisaaconceptualconceptualframeworkframeworkusedusedtotodescribedescribenetworknetworkcommunicationcommunication..ItItdefinesdefinessevensevendifferentdifferentlayers,layers,eacheachwithwithspecificspecificfunctionalitiesfunctionalitiesandandresponsibilitiesresponsibilities..?TheTheSessionSessionLayerLayerprovidesprovidesprocessprocesstotoprocessprocesscommunicationscommunicationsbetweenbetweentwotwoorormoremorenetworkednetworkedhostshosts..ThisThislayerlayerisisresponsibleresponsibleforformaintainingmaintainingproperpropercommunicationcommunicationbybyestablishing,establishing,managingmanagingandandterminatingterminatingsessionssessions(a(apropertypropertyofofTCP)TCP)betweenbetweentwotwonodesnodes..ItIttakestakescarecareofofgracefullygracefullyclosingclosingsessionssessionsandandforforsessionsessioncheckcheckpointingpointingandandrecoveryrecovery..?ConnectionConnection--oriented:oriented:Guarantees inGuarantees in--order delivery of data packets and errororder delivery of data packets and error--free transmission (e.g., free transmission (e.g., TCP).TCP).Uses routing protocols like Open Shortest Path First (OSPF) or Border Gateway Protocol (BGP) to determine the best path for data to travel.(BGP) to determine the best path for data to travel.?Additional functionalities:Additional functionalities:Performs network address translation (NAT) to allow private IP addresses to Performs network address translation (NAT) to allow private IP addresses to communicate on the public internet.communicate on the public internet.?Additional functionalities:Additional functionalities:Provides logical addressing (MAC addresses) for identifying devices on the same Provides logical addressing (MAC addresses) for identifying devices on the same network segment.network segment.?Protocols:Protocols:Transmission Control Protocol (TCP), User Datagram Protocol (UDP), port numbers.Transmission Control Protocol (TCP), User Datagram Protocol (UDP), port numbers.Uses routing protocols like Open Shortest Path First (OSPF) or Border Gateway Protocol addresses).?FunctionFunction::EstablishesEstablishesthethephysicalphysicalconnectionconnectionbetweenbetweendevicesdevicesandandtransmitstransmitsrawrawdatadatabitsbitsthroughthroughaaphysicalphysicalmediummediumlikelikecablescables(copper,(copper,fiberfiberoptic)optic)ororwirelesswirelesssignalssignals(radio(radiowaves)waves)..?UnicastUnicast::oneone--toto--oneonecommunication,communication,wherewheredatadataisistransmittedtransmittedfromfromaasinglesinglesourcesourcetotoaasinglesingledestinationdestination..?MulticastMulticast::OneOne--toto--manymanycommunication,communication,wherewheredatadataisissentsenttotoaagroupgroupofofdevicesdevicessimultaneouslysimultaneously..?BroadcastBroadcast::OneOne--toto--allallcommunication,communication,wherewheredatadataisissentsenttotoeveryeverydevicedeviceononthethenetworknetwork..Transmission Types:
Transmission Types:
Transmission
Transmissiontypestypesreferrefertotothethedifferentdifferentmethodsmethodsusedusedtototransmittransmitdatadatabetweenbetweendevicesdevicesininaacommunicationcommunicationsystemsystem..TheyTheydefinedefinehowhowinformationinformationisispackaged,packaged,sent,sent,andandreceived,received,ensuringensuringreliablereliableandandefficientefficientdatadataexchangeexchange..????????????????????