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  1. What are the advantages of a business network? A network enables employees to communicate with each other more easily, even over large distances. Networks also enable expensive resources, such as printers, to be shared, avoiding the cost of providing these resources to individual employees. Software can be deployed from a network server, thereby reducing the costs of installation on each user’s computer. Finally, networks enable employees to share an Internet connection, avoiding the cost of providing each employee with a dedicated Internet connection.

  2. How does a client/server network differ from a peer-to-peer network? A client/server network requires at least one server to be attached to the network. The server coordinates functions such as data transmission and printing. In a peer-to-peer network, each node connected to the network can communicate directly with every other node on the network. In a client/server network, a separate device exercises control over the network. Data flows more efficiently in client/server networks than in peer-to-peer networks. In addition, client/server networks have increased scalability, meaning users can be added to the network easily.

  3. What are the different classifications of client/server networks? Local area networks (LANs) are small groups of computers (as few as two) and peripherals linked together over a small geographic area. A group of computers on the floor of the office building where you work is most likely a LAN. Wide area networks (WANs) comprise large numbers of users (or of separate LANs) that are miles apart and linked together. Corporations often use WANs to connect two or more branches (such as an office in California and one in Ohio). Sometimes government organizations or civic groups establish WANs to link users in a specific geographic area (such as within a city or county). These special WANs are known as metropolitan area networks (MANs).

  4. What components are needed to construct a client/server network? Client/server networks have many of the same components of peer-to-peer networks as well as some components specific to client/server networks, including servers, a network topology, transmission media, network operating system (NOS) software, network adapters, and network navigation devices.

  5. What do the various types of servers do? Dedicated servers are used on large networks to increase efficiency. Authentication servers control access to the network and ensure that only authorized users can log on. File servers provide storage and management of user files. Print servers manage and control all printing jobs initiated on a network. Application servers provide access to application software (such as Microsoft Office). Database servers store database files and provide access to users who need the information in the databases. E-mail servers control all incoming and outgoing e-mail traffic. Communications servers are used to control the flow of information from the internal network to outside networks (such as the Internet). Web servers are used to host a Web site.

  6. What are the various network topologies (layouts), and why is network topology important in planning a network? In a bus topology, all nodes are connected to a single linear cable. Ring topologies are made up of nodes arranged roughly in a circle. The data flows from node to node in a specific order. In a star topology, nodes are connected to a central communication device (a switch) and branch out like points of a star. A hybrid topology blends two or more topologies in one network. Each topology has its own advantages and disadvantages. Topology selection depends on two main factors: (1) the network budget, and (2) the specific needs of network users (such as speed or fair allocation of resources).

  7. What types of transmission media are used in client/server networks? In addition to wireless media, three main cable types are used: twisted-pair cable, coaxial cable, and fiber-optic cable. Twisted-pair cable consists of four pairs of wires twisted around each other to reduce interference. Coaxial cable is the same type of cable used by your cable TV company to run a signal into your house. Fiber-optic cable uses bundles of glass or plastic fiber to send signals using light waves. It provides the largest bandwidth but is expensive and difficult to install. Wireless media uses radio waves to send data between nodes on a network.

  8. What software needs to run on computers attached to a client/server network, and how does this software control network communications? Network operating system (NOS) software needs to be installed on each computer and server connected to a client/server network to provide the services necessary for the devices to communicate. The NOS provides a set of common rules (called a protocol) that controls communication between devices on the network.

  9. How do network adapters enable computers to participate in a client/server network? Without a network adapter, a computer could not communicate on a network. A network adapter provides three critical functions. First, it takes low-power data signals generated by the computer and converts them into higher-powered signals that can traverse network media easily. Second, it breaks the data generated by the computer into packets and packages them for transmission across the network media. Last, it acts as a gatekeeper to control the flow of data to and from the computer.

  10. What devices assist in moving data around a client/server network? Repeaters are used to amplify signals on a network ensuring that signals are received even at the end of a long cable run. Hubs receive and retransmit signals to all devices attached to them. Switches are “smart” hubs in that they can read the addresses of data packets and retransmit a signal to its destination instead of to every device connected to the switch. Routers are used to route data between two different networks (such as between a corporate network and the Internet).

  11. What measures are employed to keep large networks secure? Access to most networks requires authentication procedures (such as having users enter a user ID and password) to ensure that only authorized users access the network. The system administrator defines access privileges for users so that they can access only specific files. Network equipment is physically secured behind locked doors, which are often protected by biometric authentication devices. Biometric devices, such as fingerprint and palm readers, use unique physical characteristics of individuals for identification purposes. Firewalls are employed to keep hackers from attacking networks through Internet connections. Packet screeners review traffic going to and from the network to ascertain whether it was generated by a legitimate user.

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