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Chapter 1 Panko and Panko Business Data Networks and Security, 9 th Edition 2013 Pearson Panko and Panko Business Data Networks and Security, 9 th Edition 2013 Pearson Slide 2 Today, we are surrounded by networks. This book will help you learn the skills you will need to participate in this networking revolution. This chapter introduces basic network concepts and issues you will use throughout the book. 2 2013 Pearson Slide 3 Difficult MaterialCentral Concept (CEPT) Take it slowly, step by step. This will require some extra work. This is a central concept (CEPT) you need to understand really well. 3 2013 Pearson Slide 4 Into the Cloud Basic Network ConceptsPacket SwitchingInternetworkingLayersInternet StandardsA Small Home Network 4 2013 Pearson Slide 5 Works at the First Bank of Paradise (FBP) in Hawai`i Develops new media marketing campaigns using Facebook, YouTube, e-mail lists, and the banks website 5 2013 Pearson Slide 6 Current project is the AlohaSmart credit card smartcard Smartcards have chips as well as mag stripes 6 2013 Pearson Slide 7 In the morning, opens his tablet to check e-mail containing remarks about his PowerPoint marketing plan Turns on his desktop computer and reworks the PowerPoint presentation Automatically uploaded to the cloud with BlueSynch Later available to his work notebook and to meeting participants 7 2013 Pearson Slide 8 The cloud imagery indicates that the user does not have to understand how systems inside the cloud operate. 8 2013 Pearson Slide 9 PowerPoint is installed on his desktop computer at home. For his work notebook computer and on his tablet, PowerPoint is stored in the cloud. He downloads it when he needs it. Pays for it by the month, as a service. It is called software as a service (SaaS). 9 2013 Pearson Slide 10 10 2013 Pearson Slide 11 On the FBP networking staff Manages the headquarters building wireless LANs Walks around doing readings with her sniffer program Learns information about access points, their signal power, and their security 11 2013 Pearson Slide 12 12 2013 Pearson Slide 13 SSIDFBP BSSID A1-B2-C3- D4-E5-F6 BB-D5-33-D4- 6B-DD 19-FF-AE-D4- EC-63 Signal-85 dBm-60 dBm Mode802.11g802.11n Channel114844 EncryptionAES-CCMP AuthenticationWPA2/PEAP VendorCisco 13 2013 Pearson Slide 14 Currently, must walk around at least daily. Even then, cannot find intermittent problems. FBP is installing a centralized wireless management system. Will be able to manage all access points centrally. She can constantly monitor the network for problems. The network will alert her to problems. The system can even make adjustments automatically. 14 2013 Pearson Slide 15 In charge of wireless security at FBP BYOD (Bring Your Own Device) Problem Number of smartphones and tablets is exploding Owned by the employees but used partially for business purposes Great diversity in smartphone and tablet operating systems Device security is improving but limited 15 2013 Pearsonl Slide 16 Claire Lorek found a rogue access point in one of her walkarounds. She and John Lee visited Albert Gomes who installed the unauthorized access point. Albert thought that the access point was secure in stealth mode. However, Claires and hackers software could find it. 16 2013 Pearson Slide 17 Rather than punish Albert Gomes, they worked to help him. His department did need more capacity. Claire would install another access point, one with strong security. John and Claire had developed an ally. 17 2013 Pearson Slide 18 Into the Cloud Basic Network Concepts Packet SwitchingInternetworkingLayersInternet StandardsA Small Home Network 18 2013 Pearson Slide 19 Working Definition 19 2013 Pearson Slide 20 20 2013 Pearson Slide 21 21 2013 Pearson Slide 22 22 2013 Pearson Slide 23 The client and the server share processing work. 23 2013 Pearson Slide 24 P2P Processing can be done without a network (as shown) or with a network. No servers are needed. 24 2013 Pearson Slide 25 Transmission Speed Measurements Bits per second (bps) Usually not bytes per second (Bps) Metric Suffixes Kilobits per second kbps (lowercase k)1,000 bits per second (not 1,024) Megabits per second Mbps1,000 kbps Gigabits per second Gbps1,000 Mbps Terabits per second Tbps1,000 Gbps 25 2013 Pearson Slide 26 File Downloads 100 kbps 1 Mbps 5 Mbps 10 Mbps 100 Mbps 1 Gbps E-mail message (250 words).15 s0 s Photograph (5 MB) 8 m1 m10 s5 s1 s0.1 s 1 Hr HTDV Video (10 Mbps) 4 d10 h2 h1 h6 m36 s Backup Synch (10 GB) 12 d28 h6 h3 h17 m2 m 26 2013 Pearson Slide 27 Live or Streaming Media 100 kbps 1 Mbps 5 Mbps 10 Mbps 100 Mbps 1 Gbps MP3 Song (10 kbps) OK Standard Quality TV (2 Mbps) OK HDTV (10 Mbps)OK Three HDTV Channels OK 27 2013 Pearson Slide 28 Into the CloudBasic Network Concepts Packet Switching InternetworkingLayersInternet StandardsA Small Home Network 28 2013 Pearson Slide 29 29 2013 Pearson Slide 30 30 2013 Pearson Slide 31 31 2013 Pearson Slide 32 32 2013 Pearson Slide 33 33 2013 Pearson Slide 34 34 2013 Pearson Slide 35 35 2013 Pearson Slide 36 36 2013 Pearson Slide 37 Each switch along the way forwards the packet out a port to another switch (or to the destination host). Individual packet switches have no knowledge of the entire path taken by the packet. We will see how this works in detail in later chapters. 37 2013 Pearson Slide 38 38 2013 Pearson Slide 39 39 2013 Pearson Slide 40 Forerunner of the Internet Funded by Larry Roberts at the Advanced Research Projects Agency (ARPA) Now the Defense Advanced Research Projects Agency (DARPA) To explore packet switching To give researchers access to ARPA-funded software on host computers in distant cities First four nodes began operation in 1969 40 2013 Pearson Slide 41 41 2013 Pearson Slide 42 42 2013 Pearson Slide 43 Into the CloudBasic Network ConceptsPacket Switching Internetworking LayersInternet StandardsA Small Home Network 43 2013 Pearson Slide 44 Bob Kahn at DARPA needed a way for researchers on one network to use resources on another network. Packets would have to travel across multiple networks. Kahn and Vint Cerf came up with the idea of connecting multiple networks by devices called routers. The original name was gateways. Generically, networks of networks are internets. Kahn created the global Internet (Capital I). 44 2013 Pearson Slide 45 45 2013 Pearson Slide 46 Capitalization of internet With an uppercase I, Internet means the global Internet we use every day. With a lowercase i, internet means any internet or the internet layer. 46 2013 Pearson Slide 47 Basically, Kahn and Cerf created a second layer of networking on top of single networks. This required the creation of a parallel set of concepts for single networks and internets. Single networks and internets use similar concepts but give these concepts different names. It is important for you to get this clear in your head. 47 2013 Pearson Slide 48 Component Generic Terminology Single Networks Internets Addresses Vary by network technology 32-bit IPv4 Addresses and 128-bit IPv6 Addresses Packets are calledPacketsFramesPackets Packet switches are called Switches Routers End-to-end routes are called Data linksRoutes 48 2013 Pearson Slide 49 Component Generic Terminology Single Networks Internets Addresses Vary by network technology 32-bit IPv4 Addresses and 128-bit IPv6 Addresses Packets are calledPacketsFramesPackets Packet switches are called Switches Routers End-to-end routes are called Data linksRoutes 49 2013 Pearson Slide 50 50 2013 Pearson Slide 51 51 2013 Pearson Slide 52 52 2013 Pearson Slide 53 Into the CloudBasic Network ConceptsPacket SwitchingInternetworking Layers Internet StandardsA Small Home Network 53 2013 Pearson Slide 54 Networks can be described at several layers of detail. Each layer provides services to the layer above it. The road provides service to the car tires. The car tires provide service to the car. The car provides service to the driver. A commercial driver provides service to the goods being delivered. 54 2013 Pearson Slide 55 1. Physical links are connections between adjacent pairs of devices 1. Physical links are connections between adjacent pairs of devices 2. The data link is the packets path through the network In this case: X-A-B-D-F-Y 2. The data link is the packets path through the network In this case: X-A-B-D-F-Y 55 2013 Pearson Slide 56 How many data links does the packet pass through? How many physical links does the packet pass through? Name them. How many data links does the packet pass through? How many physical links does the packet pass through? Name them. 56 2013 Pearson Slide 57 Formed by graduate students to create standards for the ARPANET. Called their standards Requests for Comment (RFCs). Did not feel that they had the authority to create standards, so they used the weaker term RFC. The NWG evolved into todays standards body for the Internet, the Internet Engineering Task Force (IETF). Internet standards today are still called RFCs. 57 2013 Pearson Slide 58 Basically, Kahn and Cerf created a second layer of networking on top of single networks. This required the creation of a parallel set of concepts for single networks and internets. Single networks and internets use similar concepts but give these concepts different names. It is important for you to get this clear in your head. 58 2013 Pearson Slide 59 59 Dashed line shows the path of a packet Dashed line shows the path of a packet 2013 Pearson Slide 60 60 How many physical links are there between the two hosts? How many physical links are there between the two hosts? Physical links connect adjacent devices, as noted earlier. Physical links connect adjacent devices, as noted earlier. 2013 Pearson Slide 61 61 A data link is the path of a frame through a single network, as noted earlier. There is one data link per network. How many data links are in the figure? There is one data link per network. How many data links are in the figure? 2013 Pearson Slide 62 62 A route is a packets path through an internet. Added for internets. A route is a packets path through an internet. Added for internets. How many routes are there in the figure? 2013 Pearson Slide 63 Host P transmits a packet to Host Q. There are seven networks between the hosts. 1. How many packets will there be along the way? 2. How many frames will there be along the way? 3. How many routes will there be along the way? 4. How many data links will there be along the way? 63 2013 Pearson Slide 64 64 2013 Pearson Slide 65 65 2013 Pearson Slide 66 LayerNameBroad PurposeSpecific Purpose 5Application 4Transport 3Internet 2Data Link Single- network transmission (switched or wireless) Connection across a single network, Frame formats and switch operation 1PhysicalPhysical connections between adjacent devices 66 2013 Pearson Slide 67 LayerNameBroad PurposeSpecific Purpose 5Application 4Transport Internet Transmission Application message fragmentation, error correction, congestion reduction, etc. 3InternetTransmission of packet across an internet, Packet formats, router operation 2Data Link 1Physical 67 2013 Pearson Slide 68 NumberNameBroad PurposeSpecific Purpose 5ApplicationCommunication between applications Same 4Transport 3Internet 2Data Link 1Physical 68 2013 Pearson Slide 69 Into the CloudBasic Network ConceptsPacket SwitchingInternetworkingLayers Internet Standards A Small Home Network 69 2013 Pearson Slide 70 IP Internet layer protocol Unreliable best-effort internet layer operation 70 2013 Pearson Slide 71 TCP Transport layer protocol TCP messages are called segments Provides transport layer functionality to fix problems Error correction, and so on UDP The other transport layer protocol Messages are called datagrams Unreliable, so used when reliability is not desired 71 2013 Pearson Slide 72 LayerStandard(s) Transport LayerTransmission Control Protocol (TCP) Fragmentation Error Correction Congestion control User Datagram Protocol (UDP) No Fragmentation No Error Correction No Congestion Control Internet LayerInternet Protocol (IP) IPv4 and IPv6 72 2013 Pearson Slide 73 1977 First experimental connection of three networks (Two wireless and the ARPANET) 1980s Internet opened to outside network for e-mail exchanges 73 2013 Pearson Slide 74 TCP/IP standards evolved in the 1980s Hosts could run either TCP/IP or NCP standards. 1983 All hosts were required to run TCP/IP. NSFNET In the 1980s, the NSFNET funded by NSF was the core of the Internet. NSF had an Acceptable Use Policy barring commercial activity such as e-commerce. 74 2013 Pearson Slide 75 1995 NSFNET replaced by commercial ISPs. E-commerce was no longer forbidden. The e-commerce revolution began. The World Wide Web became popular just before that. 75 2013 Pearson Slide 76 To use the Internet, you need an Internet service provider and an access line to your ISP. Your ISP gives you access and carries your packets. To use the Internet, you need an Internet service provider and an access line to your ISP. Your ISP gives you access and carries your packets. Organizations also need ISPs. Organizations also need ISPs. 76 2013 Pearson Slide 77 ISPs collectively comprise the Internet backbone. They interconnect at Network Access Points (NAPs) to exchange packets. ISPs collectively comprise the Internet backbone. They interconnect at Network Access Points (NAPs) to exchange packets. 77 2013 Pearson Slide 78 Trace the path packets take from the User PC to the Webserver. 78 2013 Pearson Slide 79 IP, TCP, and UDP are standards for delivery packets. TCP/IP also has supervisory protocols: To handle things beyond packet delivery. Managing IP addresses. Error handling, and so on. We will look at two supervisory protocols in this chapter. We will look at many more in Chapter 10. 79 2013 Pearson Slide 80 80 2013 Pearson Slide 81 81 2013 Pearson Slide 82 82 2013 Pearson Slide 83 83 2013 Pearson Slide 84 84 2013 Pearson Slide 85 85 2013 Pearson Slide 86 86 2013 Pearson Slide 87 Into the CloudBasic Network ConceptsPacket SwitchingInternetworkingLayersInternet Standard A Small Home Network 87 2013 Pearson Slide 88 88 2013 Pearson Slide 89 89 2013 Pearson Slide 90 90 2013 Pearson Slide 91 The IP gives the home one IP address. The home network has multiple devices that need IP addresses. The IP gives the home one IP address. The home network has multiple devices that need IP addresses. 91 2013 Pearson Slide 92 The access router DHCP circuit gives private IP addresses to other devices. The access router DHCP circuit gives private IP addresses to other devices. 92 2013 Pearson Slide 93 NAT allows multiple internal hosts to share a single external IP address. External sniffers cannot learn internal addresses. NAT allows multiple internal hosts to share a single external IP address. External sniffers cannot learn internal addresses. 93 2013 Pearson Slide 94 Into the CloudBasic Network ConceptsPacket SwitchingInternetworkingLayersInternet StandardA Small Home Network 94 2013 Pearson Slide 95 This is the first of four introductory chapters. The others deal with standards, security, and network and security management. Chapter 1 introduces basic network concepts and issues. Presented historically because some aspects of networking only make sense if you understand the development of internetworking. Specifically, single-network versus internet concepts and terminology (two of everything). 95 2013 Pearson Slide 96 Chapter 2 looks at standards in more depth. It will look at major characteristics of standards, such as the syntax of messages. It will focus on the data link, internet, transport, and application layers, which work by sending structured messages. 96 2013 Pearson Slide 97