1. Networks and Communication
Welcome to Chapter 9 of Visualizing Technology, fifth edition, by Debra Geoghan. This chapter explains and discusses networks and communications.
Chapter 9
Networks and Communication
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2. Copyright © 2017 Pearson Education, Inc.
Objectives
Discuss the Importance of Computer Networks
Compare Different Types of LANs and WANs
List and Describe the Hardware Used in Both Wired and Wireless Networks
List and Describe Network Software and Protocols
Explain How to Protect a Network
Chapter Nine Objectives Are:
Discuss The Importance Of Computer Networks
Compare Different Types Of Lans And Wans
List And Describe The Hardware Used In Both Wired And Wireless Networks
List And Describe Network Software And Protocols
Explain How To Protect A Network
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3. Discuss the Importance of Computer Networks
Objective 1 discusses the importance of computer networks and the characteristics of different types of networks.
Objective 1
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4. From Sneakernet to Hotspots
Computer Network
Two or more computers that share resources
Network resources include software, hardware, and files
Can save money and time
Can increase productivity
A computer network is two or more computers that share resources. Network resources include software, hardware, and files. A computer network can save money and time and increase productivity.
Objective 1
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5. From Sneakernet to Hotspots Peer-to-Peer Networks
All Computers are Considered Equal
Simplest network to set up
All computers in a P2P network belong to a workgroup
Homegroup is a Windows networking feature
A peer-to-peer (P2P) network is a network where all computers are considered equal. All computers in a P2P network belong to a workgroup. In Windows, a homegroup refers to a networking feature that consists of all computers in your home network running Windows 8 or 10 configured with the same homegroup password.
Objective 1
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6. From Sneakernet to Hotspots Client-Server Network
Has at least one server at its center
Centralizes network management, resources, and security
Users log in and are granted access based on that login
Server
Multiuser computer system
Network operating system
Clients
PCs
Other devices
A client-server network has at least one server at its center. The server provides a way to centralize network management, resources, and security. In a client-server network, users log in to a network and are granted access based on that login. A server is a multiuser computer system that runs a network operating system (NOS). A client is a personal computer or other device that connects to the server.
Objective 1
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7. Compare Different Types of LANs and WANs
Objective 2 compares different types of LANs and WANs.
Objective 2
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8. LANs and WANs Small Networks
LAN (local area network)
All connected devices or nodes located in the same physical location
A home LAN is probably a P2P network
A business LAN is more likely a client-server network
A LAN is a local area network that has all connected devices or nodes located in the same physical location.
Objective 2
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9. LANs and WANs Small Networks
PAN (personal area network)
Devices connected via Bluetooth
Bluetooth is a technology that connects peripherals wirelessly at short ranges
WLAN (wireless LAN)
Uses Wi-Fi to transmit data
A PAN, or personal area network, is a LAN that has devices connected via Bluetooth. Bluetooth is limited in range to only 10 to 100 meters. A WLAN, or wireless LAN, uses Wi-Fi to transmit data. Wi-Fi has a much larger range, higher speeds, better security, and supports more devices than Bluetooth.
Objective 2
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10. LANs and WANs LAN Topologies
Physical layout of a LAN
Three common configurations
Bus
Ring
Star
Modern LANs use star topology
Every node attached to central device
Standards – ensure that equipment made by different companies work together
Ethernet – the standard that defines the way data is transmitted over a LAN
The physical layout of a LAN is called its topology. The devices, or nodes, on the LAN can be connected in many different configurations. The most common configurations are bus, ring, or star. In a star topology, commonly used in modern LANs, every node on the network is attached to a central device such as a switch, router, or wireless access point.
Objective 2
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11. LANs and WANs Large Networks
WAN (wide area network)
Spans multiple locations
Connects multiple LANs over dedicated lines using routers
VPN (virtual private network)
A private network through the public network (Internet)
Remote users access a LAN securely without dedicated lines
Uses encryption to ensure that the data is secure
A WAN, or wide area network, is a network that spans multiple locations and connects multiple LANs over dedicated lines using routers. VPNs, or virtual private networks, create a private network through the public network, the Internet, allowing remote users to access a LAN securely without needing dedicated lines. This is less expensive, more practical for businesses, and uses encryption to ensure that the data is secure as it travels through the public network.
Objective 2
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12. LANs and WANs Large Networks
CAN (campus area network)
Hybrid of LANs and WANs
Connected using routers
MAN (metropolitan area network)
Covers a single geographic area
A CAN, or campus area network, is a hybrid of LANs and WANs connected using routers. This is used by large businesses with multiple LANs in the same location. A MAN, or metropolitan area network, covers a single geographic area.
Objective 2
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13. LANs and WANs Large Networks
SAN (storage area network)
Network between data storage devices and network servers
Cellular Networks
Use cell towers
Transmit voice and data over long distances
A SAN, or storage area network, is a network between the data storage devices and the servers on a network. Cellular networks use cell towers to transmit voice and data over long distances.
Objective 2
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List and Describe the Hardware Used in Both Wired and Wireless Networks
Objective 3 lists and describes the hardware used in both wired and wireless networks.
Objective 3
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15. Hardware Network Adapters
Communications device
Establishes connection with a network
Each device on a network must have a network adapter
Most PCs come with a built-in Ethernet adapter
RJ-45
Plugs into a wall jack, switch, router, or modem
The network hardware consists of the physical devices needed to create the network. A network adapter is a communications device used to establish a connection with a network. Other devices used to connect you to the Internet include analog modems for dial-up connections, digital modems for cable or DSL connections, and optical network terminals (ONT) for a fiber network.
Each device that connects to a network must have some type of network adapter. Most PCs come with a built-in Ethernet adapter, also known as an RJ-45. This adapter looks like a large phone jack. The cable used is called twisted-pair, Ethernet cable, or Cat-5 or Cat-6. Depending on the size of the network you are connecting to, the other end of the cable will plug into either a wall jack, switch, router, or modem.
Objective 3
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16. Hardware Network Adapters
Wi-Fi networks use the IEEE standards
USB wireless adapters
Easy connection to devices without a built-in adapter
Wi-Fi Alliance certifies wireless devices
WLAN (wireless local area network)
Ad hoc network
Two wireless devices connect directly
Infrastructure wireless network
Devices connect through a wireless access point
Wi-Fi networks in homes and public places use IEEE standards, which ensure equipment made by different companies works together. Most notebooks have built-in wireless adapters. USB wireless adapters are used to connect devices without built-in adapters. The Wi-Fi Alliance certifies wireless devices to ensure interoperability. A WLAN is a wireless local area network. Ad hoc networks occur when two wireless devices connect to each other directly. In infrastructure wireless networks, devices connect through wireless access points.
Objective 3
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17. Hardware Network Connectivity Hardware
Modem
Traditional dial-up connection
Digital modem
Cable and DSL
ONT (optical network terminal)
Used by FTTH
Router
Connects two or more networks
Additional network hardware includes a modem, digital modem, or an optical network terminal or ONT (optical network terminal). A router connects two or more networks while a switch connects multiple devices within a LAN.
Objective 3
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18. Hardware Network Connectivity Hardware
Switch
Connects multiple devices
WAP (wireless access point)
Allows wireless devices to join network
Firewall
Blocks unauthorized access to network
Both software and hardware
To set up a wireless network, you need a WAP, which allows wireless devices to join a network much like a switch. A firewall can be both software and hardware that blocks unauthorized access to a network.
Objective 3
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19. List and Describe Network Software and Protocols
Objective 4 lists and describes network software and protocols used in both wired and wireless networks.
Objective 4
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20. Software and Protocols Peer-to-Peer Network Software
No special software required
Operating systems have built- in networking capabilities
Client for Microsoft Networks
Allows remote access of files and printers on a Microsoft network
There is no special software required to create a simple peer-to-peer (P2P) network. Modern desktop operating systems have networking capabilities built into them.
Objective 4
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21. Software and Protocols Client-Server Network Software
Both client software and server software are needed on a client- server network
Client software makes requests
Server software fulfills them
Microsoft Server OS
Windows clients do not need any special client software for file and print services
Both client software and server software are needed on a client-server network. The client software makes requests, and the server software fulfills them. In a network running Microsoft Server OS, Windows clients do not need any special client software for file and print services.
Objective 4
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22. Software and Protocols Network Protocols
Protocols define the rules for communicating between devices
TCP/IP Stack
Transmission Control Protocol (TCP)
Internet Protocol (IP)
File Transfer Protocol (FTP)
Hypertext Transfer Protocol (HTTP)
Simple Mail Transfer Protocol (SMTP)
Post Office Protocol (POP)
Protocols define the rules for communication between devices. The rules define how data is formatted, transmitted, received, and acknowledged. Important protocols include TCP, IP, HTTP, FTP, POP, SMTP, DHCP, and DNS. Without protocols, devices could be physically connected and still be unable to communicate. TCP/IP is the protocol stack that runs on the Internet.
Objective 4
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23. Explain How to Protect a Network
Objective 5 lists and describes how you can protect your network.
Objective 5
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24. Protecting Your Network Layer 1: The Fence
Firewall
Examines data packets as they enter or leave a network
Will deny access to traffic based on rules the network administrator defines
In a home network, the hardware firewall is usually part of the router
In a business, the firewall is a stand- alone device
The same importance we place on protecting our home should be used with network security. The first layer of defense is a hardware-based firewall. A firewall examines the data packets as they enter or leave your network and denies access to traffic based on rules set by the network administrator.
Objective 5
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25. Protecting Your Network Layer 2: Door Locks
Determined by:
What is shared
Who is granted access
Passwords
In a network, the second layer, door locks, are represented by the network configuration determining what’s shared and who’s granted access to it. Your user names should have strong passwords that are hard to crack, and each user should be granted access only to what they need. Windows and OS X allow you to create standard users or administrators; they also include parental controls for child accounts.
Objective 5
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26. Protecting Your Network Layer 3: Alarm Systems
Each computer on the network should have its own up-to-date security software installed
The third layer of defense, alarm systems, is software-based firewalls. Individual computers on the network must be protected with firewalls and antivirus and antimalware software.
Objective 5
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27. Protecting Your Network Layer 4: Guard Dogs
Installing updates is a critical part of securing your systems
The last layer of defense, referred to as the guard dogs, is critical to security success. The network administer (or you, at home) needs to be diligent in keeping the systems on the network up-to-date and secure.
Objective 5
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Questions
Are there any questions?
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