Networks and TCP/IPTCP/IPPart OnePhysical Network TechnologiesNetwork Types by ScopeLayered ModelOSI – Open Systems InterconnectData EncapsulationSidebar - WarningOSI – Layer 1: PhysicalSlide 11OSI – Layer 2: Data LinkOSI – Layer 3: Network LayerOSI – Layer 4: Transport LayerOSI – Layer 5: Session LayerOSI – Layer 6: Presentation LayerOSI – Layer 7: Application LayerOSI – What’s it all Mean?Part TwoSidebar: MAC addressesSlide 21InternetSlide 23Internet vs. World Wide Web (WWW)IPIP – Internet ProtocolSidebar: How big is 3.4 x 1038?Slide 28Slide 29Telephone Area Code AnalogyArea CodeHierarchySlide 33How to divide up addresses for the Range of address Requirements?ClassesIP ClassesSlide 37Class AClass BClass CClass DClass ESubnetworksSubnetsSubnet MasksSlide 46NotesShorthand notationNetworks and TCP/IPPart 1TCP/IPTypically used as a single entityBUT really is…Two separate complementary protocols:TCPTransmission Control ProtocolIPInternet ProtocolPart OneNetworks in GeneralPhysical Network TechnologiesCircuit Switched NetworkConnection orientedEstablish a solid connection before communicationCircuit line reserved during whole communicationExample: Telephone networkPacket Switched NetworkStore forward networkPacket(s) sent from node to nodeIntermediate nodes store and then pass to next nodeCircuits only established to pass packet to next nodeExamples: post office, internetNetwork Types by ScopeWANWide Area Networks Large region or Continental spanTypically heterogeneous and lower speedMANMetro-area networkRegional (city wide)LANLocal area networkLimited scopeSingle building or a small campusMore typically homogeneous and high speedLayered ModelOSI ModelOSI – Open Systems InterconnectOSI ModelOpen Systems Interconnection7 layers to define communicationsWe need only be concerned with the first 4 or 5 layers at the infrastructure levelData EncapsulationSidebar - WarningThe OSI and TCP/IP models do not have 1-1 mappingsA layer in OSI may be defined by 1, 2 or 3 different TCP/IP layers/definitionsOSI – Layer 1: PhysicalHardware interconnectionCablesElectronic InterfacesReal live siliconOSI – Layer 1: PhysicalExamplesIEEE 802.5Token Ring hardware specsRS-232c“Traditional” Serial LinkIEEE-488GPIB or HPIBInstrumentation BusIEEE-1394FireWireIEEE-1284Parallel interface“Centronics”IEEE 802.3Most Common: 10/100/1000 Base T (for Ethernet)Many variants (copper, fiber, etc.)10Base2 (Coax)10Base-T100Base-T1000Base-T1000Base-X (fiber)10GBase-TOSI – Layer 2: Data LinkLocal Network AddressingBasics of getting data from one point to anotherExamplesEthernet (802.3y, 802.3z, etc.)Token Ring (802.5)ATM (Asynchronous Transfer Mode)OSI – Layer 3: Network LayerInter-networkExamplesIPIPXNovell networksAppleTalkOSI – Layer 4: Transport LayerService IdentificationExamplesTCPUDPSPXAppleTalkOSI – Layer 5: Session LayerCommunications between computersMaintains communications between applications on the computersOSI – Layer 6: Presentation Layer Standard interfaceData manipulation if needEncoding/DecodingEBCIC  ASCIISerializing ObjectsLoading / Unloading data structure into XMLOSI – Layer 7: Application LayerInterfaces directly to the applicationOSI – What’s it all Mean?Sending ApplicationSends the data down the layers on its side where it finally gets sent over the physical mediaReceiving ApplicationPhysical media receives the data and sends the data back up the layers to the receiving applicationPart Two Internet and TCP/IPSidebar: MAC addressesEvery addressable network card has a unique address48 bits long281,474,976,710,656 addresses!64 bit standard has been defined48 bit addresses will run out about 2100!Divided into 2 parts:Organization Unique Identifier (OUI) partThink of this as the manufacturer idNetwork Interface Controller (NIC) partSidebar: MAC addressesWhy not use MAC for all communication?What if network card fails and gets replaced?What if network card gets upgraded?Token ring  EthernetEthernet 10mb/s  Ethernet 100mb/sEthernet  ????What if computer gets replaced?Don’t want to update all the old card references with the new card addressInternetWhat is it?InternetFrom Wikipedia:The Internet is a worldwide, publicly accessible network of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the interlinked Web pages and other documents of the World Wide Web.Internet vs. World Wide Web (WWW)The WWW is not the InternetThe Internet is not the WWWWWW is a part of the InternetInternet services consists of:WWWeMailFTPVoIPEtc.IPInternet ProtocolIP – Internet ProtocolStandard for how computers on networks are addressedIPv4Current standard4 bytes  32-bit numbers~4 billion potential addressRunning out of address spaceIPv6Front runner for next standardRollout has begun!128-bit numbers~3.4 x 1038 potential addressesSidebar: How big is 3.4 x 1038?Course sand: ~1mm (10-3 meter)1 cubic meter of sand has:1000 x 1000 x 1000 grains109 grains (1 billion!)1 cubic kilometer has:(109)3 or 1027 grains!So 3.4 x 1038 grain would fill3.4 x 1011 cubic kilometers!Volume of the Earth:1.0832×1021Nm3 or about 1x1012 km3Fill about 1/3 Earth!Sidebar: How big is 3.4 x 1038?Another viewAbout 100 billion stars in a galaxy (1011)About 100 billion galaxies 1022 stars in the universe!Enough address for the all the stars in 1016 universes10,000,000,000,000,000-or-10 quadrillion!Sidebar: How big is 3.4 x 1038?And now the bad news:Approximations vary, but best guess are there are about 1 x 1079 atoms in the universeIPv6 can’t give each atom it’s own unique IP address Telephone Area Code AnalogyEvery telephone has a four part numberCountry codeUnited States – 1UK – 44Ireland - 353Area