Transcript File
Information Technology INT1001 Lecture 8 Networks 1 Computers Are Your Future Tenth Edition Chapter 8: Networks: Communicating & Sharing Resources Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 2 Networks: Communicating & Sharing Resources Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 3 Network Fundamentals A network links multiple computer systems to enable them to share data and resources. The two main categories of computer networks are: Local area network (LAN) Wide area network (WAN) Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 4 Network Fundamentals Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 5 Network Fundamentals A local area network (LAN) May be wireless or connected through cables Covers a limited geographic area A wide area network (WAN) Links computer systems that can be thousands of miles apart May require long-distance transmission media Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 6 Network Fundamentals Communication devices Required to convert data into signals that can be transferred over wired or wireless media Convert data to and from analog signals to digital signals Assist in digital communication Enhance signal strength Enable effective data transfer Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 7 Network Fundamentals Communication devices include: Computers Modems Routers Switches Network interface cards (NICs) Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 8 Network Fundamentals A computer is called a client or a node when it is part of a network. A node can be any computer or peripheral device on a network. A computer needs a network interface card (NIC) to connect to a network. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 9 Network Fundamentals Routers Connect two or more networks Determine the best route to transmit data Switches Provide a function similar to that of a router Move data within one network Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 10 Network Fundamentals The majority of networks have a file server, a special computer that holds the network’s programs, data files, and network operating system (NOS). Network operating systems provide file directories for file and resource location, computerized software update distribution, and Internet services support. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 11 Advantages & Disadvantages of Networking Advantages of networking Hardware cost reduction Sharing of information, data, and applications Data management centralization Linking of people Disadvantages of networking Loss of autonomy Lack of privacy Security threats Productivity loss Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 12 Local Area Networks Local area networks can be classified as either peer-to-peer or client/server. Peer-to-peer (P2P) networks: Share files without a file server Are easy to set up Are normally used for home or small offices Slow down if there are too many users Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 13 Local Area Networks Client/server networks: Made up of one or more file servers and clients Client requests sent to server Wired or wireless connections Do not slow down with heavy usage Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 14 Local Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 15 Local Area Networks A network topology The physical design of a LAN Responsible for resolving the problem of contention Conflict that occurs when two or more computers on the network attempt to transmit at the same time Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 16 Local Area Networks Three types of LAN topologies are: Bus topology, which is used primarily in comparatively small environments such as a home or small office. Star topology, which works best in environments such as office buildings, computer labs, and WANs. Ring topology, which is best used within a division of a company or on one floor of a multiple floor building. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 17 Local Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 18 Local Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 19 Local Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 20 Local Area Networks Protocols are the standards used by networks to permit communication between network-connected devices. A network’s protocol suite contains the protocols of the network and specifies its network architecture, or how the network works. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 21 Local Area Networks Ethernet is the most-used local area network protocol. The two versions of Ethernet, which use twisted-pair wiring and switches, are: 10Base-T (10 Mbps) 100Base-T (100 Mbps) Wi-Fi uses radio waves to provide a wireless LAN standard. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 22 Local Area Networks Popular LAN Protocols Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 23 Local Area Networks Popular Wireless Networking Standards Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 24 Wide Area Networks Wide area networks are used to link computers spread over large geographic areas. The two distinguishing components of a WAN, not part of a local area network, are: A point of presence (POP) A backbone Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 25 Wide Area Networks A point of presence (POP) is the connection point of a WAN used by individuals to obtain access to the network. Backbones are transmission lines that have the ability to handle the massive traffic associated with a WAN. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 26 Wide Area Networks Protocols Transmission Control Protocol (TCP) Internet Protocol (IP) Defines how Internet-connected computers can exchange, control, and confirm messages Provides a distinct identification to any computer connected to the Internet – the IP address TCP/IP Together, they define how the Internet works Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 27 Wide Area Networks The technologies on which WAN protocols are based include: Circuit switching, used by the public switched telephone network (PSTN), sends data is sent over a physical end-to-end circuit between the sending and receiving computers. Packet switching, used by the Internet, divide and send outgoing messages as packets, which are reassembled upon receipt. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 28 Wide Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 29 Wide Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 30 Wide Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 31 Wide Area Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 32 Wide Area Networks Circuit switching Data sent over a physical circuit Best when avoiding delivery delay is vital High-speed electronic switches make connections Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 33 Wide Area Networks Packet switching Message divided into numbered packets Sent to router to distribute Packets sent through multiple paths Message reconstituted Packet switching vs. circuit switching More efficient Less expensive More reliable Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 34 Wide Area Networks WAN applications include: E-mail Conferencing Document exchange Remote database access Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 35 Home Network Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 36 Wired Home Networks Home networks: Provide users with the ability to share files and other resources Can be configured as either wired or wireless Utilize the Ethernet communications standard to stipulate how data is transmitted Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 37 Wired Home Networks Computers on an Ethernet network are linked through a communication device such as a switch or router. A switch permits the transmission of data on a single network. A router permits the transmission of data on multiple networks, including the Internet. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 38 Wired Home Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 39 Wired Home Networks Home power-line networks connect computers through the electrical wiring. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 40 Wireless Home Networks Home Wi-Fi network A wireless network Uses radio signals to transmit data Data transmission accomplished through network access points Communications devices Wireless routers Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 41 Wireless Home Networks Wireless home networks can be: Peer-to-peer Client/server Peripherals must be within the range of the network router—approximately 100 to 300 feet. Wireless networks use the 802.11 specification for wireless transmission. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 42 Wireless Home Networks Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 43 The Future of Home Networking In the future, home networking systems: Will most likely be wireless Will provide such features as: Controlling household appliances Preparing food Maintaining a home’s appearance Managing home network events Temperature regulation Communication Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 44 What You’ve Learned Computer networks of two or more linked computers share resources and exchange data. The two main types of networks are local area networks (LANs) and wide area networks (WANs). There are advantages and disadvantages to using a computer network. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 45 What You’ve Learned The two main categories of local area networks are peer-to-peer and client/server. The topologies of a LAN include the bus topology, the ring topology, and the star topology. The manner in which network devices communicate is defined by protocols. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 46 What You’ve Learned The Ethernet is the most popular LAN protocol. Distinguishing components of a WAN, when compared with a LAN, are its point of presence (POP) and backbones. WAN connections may be made through analog telephone calls or digital hookups. Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 47 What You’ve Learned The technologies on which WAN protocols are based use either circuit switching (PSTN) or packet switching (the Internet). Copyright © 2009 Pearson Education, Inc. Publishing as Prentice Hall 48