1. A+ Guide to Managing and Maintaining Your PC, 7e
Chapter 8
Networking Essentials

2. Objectives Identify the different elements of a network
Differentiate network classification according to categories, namely, size and protocol
Understand different networking technologies
Identify essential hardware used in networking
Understand what is an IP address and how it works
Understand basic networking protocol
A+ Guide to Managing and Maintaining Your PC, 7e

3. Networking Definition
What is a Computer network
Two or more computers communicating through a medium whether in a cable or in a wireless manner or both.
Three elements of a network
Source (transmitter)
Medium (line, circuit or cable)
Sink (receiver)
source
medium
sink
A+ Guide to Managing and Maintaining Your PC, 7e

4. Category of Network according to size and area
Categorized by size and physical area covered
PAN (Personal Area Network)
LAN (Local Area Network)
MAN (Metropolitan Area Network)
WAN (Wide Area Network)
A+ Guide to Managing and Maintaining Your PC, 7e

5. Category of Network according to size and area
WAN
MAN
LAN
PAN
A+ Guide to Managing and Maintaining Your PC, 7e

6. Category of Network according to size and area
Categorized by size and physical area covered
PAN – devices like PDA, cellphone communicating in very close range/proximity up to 100 meters.
LAN – devices interconnected in a limited and close-type area like school laboratory, a building or home.
MAN – networks that span normally wider geographic location of up to 30 miles like a city or a metropolitan.
WAN – networks that span beyond 30 miles a whole country or country-to-country etc. A good example of WAN is the Internet.
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7. Category of Network according to Topology
Topology – is the physical and logical layout of the network that interconnects different nodes (e.g. computer, network devices).
Main topologies: Bus, Ring, Star, and Mesh
Hybrid topologies: star-bus, star-ring
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8. Bus Topology Bus topology Transmitting packet across bus
Consists of cables connecting PCs or file servers
Terminator attached to each end of bus cable segment
Transmitting packet across bus
Detected by all nodes on segment
Given time limit to reach destination
Advantages of bus design
Requires less cable than other topologies
Easy to extend bus with a workstation
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9. A+ Guide to Managing and Maintaining Your PC, 7e

10. Bus Topology (continued)
Disadvantages of bus topology
High management costs
Can become quickly congested with network traffic
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11. Ring Topology Ring topology: continuous data path
Workstations attached to cable at points around ring
Transmitting data across ring topology
Goes around ring to reach destination
Continues until ends at source node
Advantages to ring topology
Easier to manage than bus
Handles high volume network better than bus
Suited to transmitting signals over long distances
Disadvantages to ring topology
More expensive to implement than bus
Fewer equipment options than bus
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12. A+ Guide to Managing and Maintaining Your PC, 7e

13. Star Topology
Star topology: multiple nodes attached to central device (hub, switch, router)
Cable segments radiate from center like a star
Example: workstations connected to switch
Advantages of star topology
Start-up costs comparable to ring topology
Easier to manage, defective nodes quickly isolated
Easier to expand by connecting nodes or networks
Offers better equipment and high-speed options
Disadvantages of star topology
Failure of central device may cause network failure
Requires more cable than bus
A+ Guide to Managing and Maintaining Your PC, 7e

14. Hands-on Networking Fundamentals

15. Mesh Topology Mesh topology Mesh topology used less on LANs
Every node connected to every other node in network
Provides network with fault tolerance
Fault tolerance: built-in protection against failure
If link breaks, nodes can still communicate
Alternate communication paths increase as number of nodes increase
Mesh topology used less on LANs
Expensive to implement
Mesh topology often used in MANs and WANs
Hands-on Networking Fundamentals

16. Hands-on Networking Fundamentals

17. Networking Technologies
Bandwidth: data transmission rate or the number of bits that can be transmitted over a network at one time (e.g. 56Kbps, 10Mbps, 1Gbps).
Data throughput: actual network transmission speed
Latency: delays in network transmissions
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18. Networking Technologies (cont’d.)
Internet Service Provider (ISP)
Required for Internet connection
Upload speed is slower than download speed
Communicating devices require same protocol
Protocol is a set of rules that governs interaction and in a network environment it means the rule that governs the communication between computers.
Internet protocol: TCP/IP (group of protocols)
Data is broken into segments, segment are put into packets
Figure 17-1 Use an ISP to connect to the Internet
Courtesy: Course Technology/Cengage Learning
A+ Guide to Managing and Maintaining Your PC, 7e

19. Networking Technologies – Speed and Common Uses
Technology
Speed or Speed Range
Common Uses
Dial-up or regular telephone
Up to 56 Kbps
Slow access to ISP using modem and a telephone line
ADSL (Assymetric DSL)
Up to 640Kbps upstream and up to 8 Mbps downstream
Commonly used by ISP today that are more affordable for their customers
SDSL (Symmetric DSL)
Up to 2.3 Mbps
Still used by today’s ISP but more suited for business. Both upstream and downstream are of the same speed.
Fiber Optic, Optical Carrier Level
Up to 50Mbps and Up to 160Gbps respectively
Used as dedicated line for ISP to business and as an Internet backbone respectively.
T1, T2 & T3
1.54Mbps, 6Mpbs and 45Mbps respectively
Used for dedicated line for businesses like banks to ISP
802.11a, g, n
Up to 54Mbps, 54Mpbs and 160Mbps respectively
Used for wireless networking
Ethernet, Fast Ethernet, Gigabit Ethernet
10Mpbs, 100Mbps and 1Gbps respectively
Used in Local Area Network
Table 17-1 Networking technologies
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20. Broadband Technologies
Connect to the Internet
Cable modem, DSL, fiber-optic, satellite, ISDN (Integrated Services Digital Network)
Cable modem communication
Uses existing cable lines
Always connected (always up)
TV signals and PC data signals share same coax cable
Cable modem converts PC’s digital signals to analog
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21. Broadband Technologies (cont’d.)
DSL (Digital Subscriber Line)
Group of broadband technologies
Wide range of speeds
Uses ordinary copper phone lines and unused voice frequencies
Always connected
Some DSL services offer connect on demand
Asymmetric DSL (ADSL): one upload speed, faster download speed
Symmetric DSL (SDSL): equal bandwidths in both directions
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22. Broadband Technologies (cont’d.)
Satellite provides high-speed Internet connections in remote areas
Available everywhere (airplanes)
Disadvantage: latency when uploading
Figure 17-5 Communication by satellite can include television and Internet access
Courtesy: Course Technology/Cengage Learning
A+ Guide to Managing and Maintaining Your PC, 7e

23. Broadband Technologies (cont’d.)
Fiber optic dedicated point-to-point (PTP)
No line sharing
Broadband fiber-optic cable
Television, Internet data, voice communication
Verizon technology: Fiber Optic Service (FiOS)
Cabling endpoints: carrier dependent
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24. Wireless Technologies
Use radio waves or infrared light
Useful in places where cables difficult to install
Security methods required
Encrypt data
WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access), WPA2 (Wi-Fi Protected Access 2)
Disable SSID broadcasting
SSID: name of the wireless access point
Filter MAC addresses
MAC (Media Access Control) address: 6-byte number uniquely identifying network adapter
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25. Two Basic Networking Setup
Peer-to-Peer
Two (or more) computers communicating each other in which either computer could act as a Server or a Client.
Client and Server
One computer act as a Server or the computer who is solely responsible for distributing resources (like Database, Web connection) among the network and the rest act as a client or the who request resources from the Server.
A+ Guide to Managing and Maintaining Your PC, 7e
Table 17-2 Variations of Ethernet and Ethernet cabling

26. Hardware Used by Local Networks
Hardware devices creating and connecting to networks
Desktop and laptop devices
Cables and their connectors
Hubs
Switches
Wireless access devices
Routers
A+ Guide to Managing and Maintaining Your PC, 7e

27. Networking Adapters and Ports
Ethernet network adapters and ports
Network adapter: direct connection to a network
Takes the form of a network interface card (NIC)
External devices connect using USB port
Provides RJ-45 port
Network cards provide status light indicators
Useful in troubleshooting
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28. Networking Adapters and Ports (cont’d.)
WI-FI wireless adapters
802.11b/g/n connections use a variety of devices
Laptops sold today have antenna embedded inside
Figure Four different types of wireless network adapters: (a) wireless NIC that fits in a PCI slot; (b) onboard wireless with an antenna that can be moved; (c) PC Card wireless NIC with embedded antenna; and (d) wireless NIC that uses a USB port on a desktop or notebook computer. Courtesy: Course Technology/Cengage Learning
A+ Guide to Managing and Maintaining Your PC, 7e

29. Cables and Connectors Types of Ethernet cabling:
Twisted-pair
Unshielded (UTP) and shielded twisted pair (STP)
Coaxial cable: single copper wire with braided shield
Fiber-optic: glass strands inside protective tubing
Ethernet types (categorized by speed):
10-Mbps Ethernet
100-Mbps or Fast Ethernet
1000-Mbps or Gigabit Ethernet

30. Hubs and Switches
Star topology: nodes connected to a centralized hub or switch
Hub: pass-through device
No regard for data
Switch: keeps a table of all devices connected to it
Determines path when sending packets
Network cables
Patch cable (straight-through cable): connects computer to hub or switch
Crossover cable: connects two like devices
A+ Guide to Managing and Maintaining Your PC, 7e

31. Hubs and Switches (cont’d.)
Some switches have uplink port for patch cable use
Some switches use auto-uplinking
Figure An Ethernet network with three switches
Courtesy: Course Technology/Cengage Learning
A+ Guide to Managing and Maintaining Your PC, 7e

32. Wireless Access Points
Allows wireless device connection to LAN
Devices communicate through access point
May double as a router
Figure Nodes on a wireless LAN connect to a wired network by way of an
access point. Courtesy: Course Technology/Cengage Learning
A+ Guide to Managing and Maintaining Your PC, 7e

33. Routers
Figure A router stands between a local network and the Internet and manages traffic between them. Courtesy: Course Technology/Cengage Learning
A+ Guide to Managing and Maintaining Your PC, 7e

34. Routers (cont’d.) DHCP (dynamic host configuration protocol) server
Provides IP addresses to network computers
Dynamic IP addressing
No need to assign, keep up with unique IP addresses
Router functions
Router
Switch
DHCP server
Wireless access point
Firewall with or without NAT redirection
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35. Understanding IP Addresses and How They Are Used (cont’d.)
IP address identifies network and host
Classes are based on the number of possible IP addresses in each network within each class
Table 17-4 Classes of IP addresses
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36. Understanding IP Addresses and How They Are Used
IP address: 32 bits long, made up of 4 bytes, each 8 bits long
Four decimal numbers separated by periods
Largest possible 8-bit number
(255 decimal)
Largest possible decimal IP address
binary
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37. Checking IP Address
To check in your own IP Address go to StartRun then type cmd and press enter.
On DOS Command prompt type ipconfig then press enter.
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38. Understanding IP Addresses and How They Are Used (cont’d.)
Public IP addresses: available to the Internet
Private IP addresses: used on private intranets
Use router with NAT redirection for Internet access
IEEE recommendations
through
through
through
Table 17-6 Reserved IP addresses
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39. Understanding IP Addresses and How They Are Used (cont’d.)
Dynamic IP address
Assigned for current connection only (lease)
Managed by DHCP server
DHCP client: workstations working with DHCP server
DHCP software resides client and server
Configuring a DHCP server
IP address ranges available for clients
Automatic Private IP Address (APIPA) service
Used if attempt fails
Address range x.y
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40. Summary A network is a system interconnecting two or more PCs
Basic network types
PAN, LAN, Wireless LAN, MAN, or WAN
There are many broadband technologies
Cable and DSL popular
Major issue for wireless networks is security
Types of hardware
Adapters, routers, hubs, switches
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41. Summary (cont’d.) Three layers of communication
Hardware, operating system, application
An IP address is a 32-bit address identifying network node
Connecting to a wireless networks
Public, unsecured hotspots or private, secured hotspots
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