Data Communications and Networking, With TCP/IP Protocol Suite (PDF)

Because learning changes everything. ® Chapter 01 Introduction Data Communications and Networking, With TCP/IP protocol suite Sixth Edition Behrouz A. Forouzan © 2022 McGraw Hill, LLC. All rights reserved....

Because learning changes everything. ® Chapter 01 Introduction Data Communications and Networking, With TCP/IP protocol suite Sixth Edition Behrouz A. Forouzan © 2022 McGraw Hill, LLC. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill, LLC.  Chapter 1: Outline 1.1 DATA COMMUNICATIONS 1.2 NETWORKS 1.3 NETWORK TYPES 1.4 PROTOCOL LAYERING 1.5 TCP/IP PROTOCOL SUITE 1.6 THE OSI MODEL © McGraw Hill, LLC 2  1.1 DATA COMMUNICATIONS Data communication is the exchange of data between two devices via some form of transmission media. It depends on four characteristics: 1. Delivery 2. Accuracy 3. Timeliness 4. Jitter © McGraw Hill, LLC 3  1.1.1 Data 1. Message 2. Sender, 3. Receiver, 4. Medium of communication 5. Protocol. © McGraw Hill, LLC 4  Figure 1.1 Five components of data communication The communication system includes five major components: sender, receiver, message to be communicated, medium of communication, and protocol for both sender and receiver. Both sender and receiver protocols consist of 'n' number of rules. © McGraw Hill, LLC 5  1.1.2 Message Information today comes in different forms such as text, numbers, images, audio, and video. © McGraw Hill, LLC 6  Text Text is represented as a bit pattern, a sequence of bits 0s and 1s. Different sets of bit patterns have been designed to represent text symbols. Each set is called a code, and the process of representing symbols is called coding. Today, the prevalent coding system is called Unicode. © McGraw Hill, LLC 7  Numbers Bit patterns also represent numbers. However, a code such as ASCII does not represent numbers; the number is directly converted to a binary number to simplify mathematical operations. © McGraw Hill, LLC 8  Images Bit patterns also represent images. In its simplest form, an image comprises a matrix of pixels (picture elements), where each pixel is a small dot. The size of the pixel depends on the resolution. For example, an image can be divided into 1000 pixels or 10,000 pixels. In the second case, there is a better representation of the image (better resolution), but more memory is needed to store the image. Images are represented as bit patterns using either RGB or YCM. RGB: Red Green Blue YCM : Yellow, Cyan, and Magenta © McGraw Hill, LLC 9  Audio Audio refers to the recording or broadcasting of sound or music, represented as analog or digital signals. © McGraw Hill, LLC 10  Video Videos can be a continuous images or a combination of images. © McGraw Hill, LLC 11  1.1.3 Data Flow Communication between two devices can be simplex, half-duplex, and duplex as shown in Figure 1.2. © McGraw Hill, LLC 12  Figure 1.2 Data flow (simplex, half-duplex, full-duplex) Access the text alternative for slide images. © McGraw Hill, LLC 13  Simplex In simplex mode the communication is in one direction. Only one of the two connected devices can send or receive. © McGraw Hill, LLC 14  Half-Duplex In half-duplex, each station can send or receive, but not at the same time. © McGraw Hill, LLC 15  Full-Duplex In full-duplex, both stations can send or receive at the same time. © McGraw Hill, LLC 16  1-2 NETWORKS A network is the interconnection of a set of devices capable of communication. In this definition, a device can be a host such as a large computer, desktop, laptop, workstation, cellular phone, or security system. A device in this definition can also be a connecting device such as a router a switch, a modem that changes the form of data, and so on. © McGraw Hill, LLC 17  1.2.1 Network Criteria A network must be able to meet a certain number of criteria. The most important of these are: performance, reliability, and security. © McGraw Hill, LLC 18  Performance Performance can be measured in many ways, including transit time and response time. Transit time is the amount of time required for a message to travel from one device to another. Response time is the elapsed time between an inquiry and a response. © McGraw Hill, LLC 19  Reliability In addition to accuracy of delivery, network reliability is measured by the frequency of failure, the time it takes a link to recover from a failure, and the network’s robustness in a catastrophe. © McGraw Hill, LLC 20  Security Network security issues include protecting data from unauthorized access, protecting data from damage and development, and implementing policies and procedures for recovery from breaches and data losses. © McGraw Hill, LLC 21  1.2.2 Physical Structures Before discussing networks, we need to define some network structures. © McGraw Hill, LLC 22  Types of Connection A network is two or more devices connected through links. A link is a communications pathway that transfers data from one device to another. There are two possible types of connections: point-to-point and multipoint (see Figure 1.3) © McGraw Hill, LLC 23  Figure 1.3 Types of connection Access the text alternative for slide images. © McGraw Hill, LLC 24  Types of Connections A point-to-point connection provides a dedicated link between two devices. The entire capacity of the link is reserved for transmission between those two devices. Most point-to-point connections use an actual length of wire or cable to connect the two ends, but other options, such as microwave or satellite links, are also possible A multipoint (also called multidrop) connection is one in which more than two specific devices share a single link. In a multipoint environment, the capacity of the channel is shared, either spatially or temporally. If several devices can use the link simultaneously, it is a spatially shared connection. If users must take turns, it is a timeshare connection. © McGraw Hill, LLC 25  Physical Topology The term physical topology refers to the way in which a network is laid out physically. Two or more devices connect to a link; two or more links form a topology. The topology of a network is the geometric representation of the relationship of all the links and linking devices (usually called nodes) to one another. There are four basic topologies possible: mesh, star, bus, and ring. © McGraw Hill, LLC 26  Figure 1.4 A fully connected mesh topology n=5 10 links Access the text alternative for slide images. © McGraw Hill, LLC 27  Figure 1.5 A star topology © McGraw Hill, LLC 28  Figure 1.6 A bus topology Access the text alternative for slide images. © McGraw Hill, LLC 29  Figure 1.7 A ring topology Access the text alternative for slide images. © McGraw Hill, LLC 30  1-3 NETWORK TYPES A network can be of two types: LANs and WANs © McGraw Hill, LLC 31  1.3.1 Local Area Network (LAN) A local area network (LAN) is usually privately owned and connects some hosts in a single office, building, or campus. © McGraw Hill, LLC 32  Figure 1.8 An isolated LAN in the past and today Access the text alternative for slide images. © McGraw Hill, LLC 33  1.3.2 Wide Area Network (WAN) A wide area network (WAN) is also a connection of devices capable of communication. a WAN has a wider geographical span, spanning a town, a state, a country, or even the world. © McGraw Hill, LLC 34  Point-to-Point WAN A point-to-point WAN is a network that connects two communicating devices through a transmission media (cable or air). Figure 1.9 shows an example of a point-to-point WAN. © McGraw Hill, LLC 35  Figure 1.9 A point-to-point WAN Access the text alternative for slide images. © McGraw Hill, LLC 36  Switched WAN A switched WAN is a network with more than two ends. A switched WAN is used in the backbone of global communication today. Figure 1.10 shows an example of a switched WAN. © McGraw Hill, LLC 37  Figure 1.10 A switched WAN Access the text alternative for slide images. © McGraw Hill, LLC 38  Internetwork Today, it is very rare to see a LAN or a WAN in isolation; they are connected to one another. When two or more networks are connected, they make an internetwork or internet. © McGraw Hill, LLC 39  Figure 1.11 An internetwork made of two LANs and one WAN Access the text alternative for slide images. © McGraw Hill, LLC 40  Figure 1.12 A heterogeneous network made of WANs and LANs Access the text alternative for slide images. © McGraw Hill, LLC 41  1.3.3 The Internet An internet (note the lowercase i) is two or more networks that can communicate with each other. The most notable internet is called the Internet (uppercase I) and is composed of millions of interconnected networks. Figure 1.13 shows a conceptual (not geographical) view of the Internet. © McGraw Hill, LLC 42  Figure 1.13 The Internet today Access the text alternative for slide images. © McGraw Hill, LLC 43  1.3.4 Accessing the Internet The Internet today is an internetwork that allows any user to become part of it. The user, however, needs to be physically connected to an ISP. The physical connection is normally done through a point-to-point WAN. © McGraw Hill, LLC 44 1.45 THE INTERNET The Internet has revolutionized many aspects of our daily lives. It has affected the way we do business as well as the way we spend our leisure time. The Internet is a communication system that has brought a wealth of information to our fingertips and organized it for our use. Topics discussed in this section: A Brief History The Internet Today (ISPs) © McGraw Hill, LLC 1.46 THE INTERNET Internet Elements © McGraw Hill, LLC 1.47 Example Configuration The figure illustrates some of the typical communications and network elements in use today. In the upper-left-hand portion of the figure, we see an individual residential user connected to an Internet service provider (ISP) through some sort of subscriber connection. The Internet consists of a number of interconnected routers that span the globe. The routers forward packets of data from source to destination through the Internet. The lower portion shows a LAN implemented using a single Ethernet switch. This is a common configuration at a small business or other small organization. © McGraw Hill, LLC 1.48 Figure 1.13 Hierarchical organization of the Internet NAP: Network Access Point © McGraw Hill, LLC