Slides for Chapter 3: Networking and InternetworkingFigure 3.1 Network performanceFigure 3.2 Conceptual layering of protocol softwareFigure 3.3 Encapsulation as it is applied in layered protocolsFigure 3.4 Protocol layers in the ISO Open Systems Interconnection (OSI) modelFigure 3.5 OSI protocol summaryFigure 3.6 Internetwork layersFigure 3.7 Routing in a wide area networkFigure 3.8 Routing tables for the network in Figure 3.7Figure 3.9 Pseudo-code for RIP routing algorithmFigure 3.10 Simplified view of part of a university campus networkFigure 3.11 Tunnelling for IPv6 migrationFigure 3.12 TCP/IP layersFigure 3.13 Encapsulation in a message transmitted via TCP over an EthernetFigure 3.14 The programmer's conceptual view of a TCP/IP InternetFigure 3.15 Internet address structure, showing field sizes in bitsFigure 3.16 Decimal representation of Internet addressesFigure 3.17 IP packet layoutFigure 3.18 A typical NAT-based home networkFigure 3.19 IPv6 header layoutFigure 3.20 The MobileIP routing mechanismFigure 3.21 Firewall configurationsFigure 3.22 IEEE 802 network standardsFigure 3.23 Ethernet ranges and speedsFigure 3.24 Wireless LAN configurationFigure 3.25 Bluetooth frame structureFrom Coulouris, Dollimore, Kindberg and BlairDistributed Systems: Concepts and DesignEdition 5, © Addison-Wesley 2012Slides for Chapter 3: Networking and InternetworkingInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.1Network performancekmInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.2Conceptual layering of protocol softwareLayer nLayer 2Layer 1Message sentMessage receivedCommunicationmediumSender RecipientInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.3Encapsulation as it is applied in layered protocolsPresentation headerApplication-layer messageSession headerTransport headerNetwork headerInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.4Protocol layers in the ISO Open Systems Interconnection (OSI) modelApplicationPresentationSessionTransportNetworkData linkPhysicalMessage sentMessage receivedSender RecipientLayersCommunicationmediumInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.5OSI protocol summaryLayer Description ExamplesApplication Protocols that are designed to meet the communication requirements ofspecific applications, often defining the interface to a service. HTTP, FTP, SMTP,CORBA IIOPPresentation Protocols at this level transmit data in a network representation that isindependent of the representations used in individual computers, which maydiffer. Encryption is also performed in this layer, if required.Secure Sockets(SSL),CORBA DataRep.Session At this level reliability and adaptation are performed, such as detection offailures and automatic recovery.Transport This is the lowest level at which messages (rather than packets) are handled.Messages are addressed to communication ports attached to processes,Protocols in this layer may be connection-oriented or connectionless.TCP, UDPNetwork Transfers data packets between computers in a specific network. In a WANor an internetwork this involves the generation of a route passing throughrouters. In a single LAN no routing is required.IP, ATM virtualcircuitsData link Responsible for transmission of packets between nodes that are directlyconnected by a physical link. In a WAN transmission is between pairs ofrouters or between routers and hosts. In a LAN it is between any pair of hosts.Ethernet MAC,ATM cell transfer,PPPPhysical The circuits and hardware that drive the network. It transmits sequences ofbinary data by analogue signalling, using amplitude or frequency modulationof electrical signals (on cable circuits), light signals (on fibre optic circuits)or other electromagnetic signals (on radio and microwave circuits).Ethernet base- bandsignalling, ISDNInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.6Internetwork layersUnderlying networkApplicationNetwork interfaceTransportInternetworkInternetwork packetsNetwork-specific packetsMessageLayersInternetworkprotocolsUnderlyingnetworkprotocolsInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.7Routing in a wide area networkHostsLinksor local networksAD EBC125436RoutersInstructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.8Routing tables for the network in Figure 3.7Routings from D Routings from ETo Link Cost To Link CostABCDE336local612201ABCDE4456local21110Routings from A Routings from B Routings from CTo Link Cost To Link Cost To Link CostABCDElocal113101212ABCDE1local21410121ABCDE22local5521021Instructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.9Pseudo-code for RIP routing algorithmSend: Each t seconds or when Tl changes, send Tl on each non-faulty outgoing link.Receive: Whenever a routing table Tr is received on link n:for all rows Rr in Tr {if (Rr.link | n) {Rr.cost = Rr.cost + 1;Rr.link = n;if (Rr.destination is not in Tl) add Rr to Tl; // add new destination to Tlelse for all rows Rl in Tl {if (Rr.destination = Rl.destination and (Rr.cost < Rl.cost or Rl.link = n)) Rl = Rr;// Rr.cost < Rl.cost : remote node has better route// Rl.link = n : remote node is more authoritative}}}Instructor’s Guide for Coulouris, Dollimore, Kindberg and Blair, Distributed Systems: Concepts and Design Edn. 5 © Pearson Education 2012 Figure 3.10Simplified view of part of a university campus networkfilecomputedialuphammerhenry hotpoint138.37.88.230138.37.88.162bruno138.37.88.249router/sickle138.37.95.241138.37.95.240/29138.37.95.249copper138.37.88.248firewallweb138.37.95.248/29serverdesktop computers