Networking

1
Networking

• Chapter 23

2
Overview

• In this chapter, you will learn to
• Explain network technologies
• Explain network operating systems
• Install and configure wired networks
• Install and configure wireless networks
• Troubleshoot networks

3
Networking Technologies
4
Sneakernet

• To share files used to require making copies to a
  floppy and running them over to someone
  elsesneakernet
• A way needed to be devised for computers to share
  information and resources
• A network is two or more computers connected
  together to share resources

5
The Big Questions

• How will each computer be identified?
• If two or more computers want to talk at the same
  time, how do you ensure all conversations are
  understood?
• What kind of wire should be used to connect the
  computers together?
• How many wires in the cable? How thick? How long?
  What type of connectors?
• How can access to data and peripherals be
  controlled?
• And the list goes on and on

6
A Few Basics

• A client machine requests information or
  services
• Uses a network interface card (NIC) to define the
  client on the network and to physically make a
  connection
• A medium to connect the devices is needed
• Cable or wireless
• The operating system needs to understand how to
  network
• A server provides information or services to the
  client

7
Packets, Frames, and NICs

• Data is broken up into small pieces and moved
  about the network in chunks called packets or
  frames
• Every network interface card (NIC) has a built-in
  identifier called a Media Access Control (MAC)
  address
• No two NICs have the same MAC address anywhere in
  the world
• Burned into a chip on the card

8
MAC Address

• Start ? Programs ? Accesories ? System Tools ?
  System Information

9
Packet Fields

• Packets contain the following fields
• MAC address of the network card that it is being
  sent to
• MAC address of the network card that sent the
  packet
• Data
• Data check or cyclic redundancy check
  (CRC) used to verify the datas
  integrity

10
Protocols

• Protocols are sets of rules
• May be used to define packet types, cabling and
  connectors, addresses, and much more
• A hardware protocol defines how to get data from
  one computer to another
• Ethernet is the dominant standard for todays
  networks
• Coaxial
• Unshielded twisted pair
• Fiber optic
• Token Ring was developed by IBM but is loosing
  popularity

11
Coaxial Ethernet

• Early Ethernet networks used coaxial cable (or
  just coax)
• Composed of a center cable surrounded by
  insulation, a shield of braided cable, and an
  outside protective cover
• A different type of coaxial cable is used by your
  VCR and TV

12
Thick Ethernet 10Base5

• Thick Ethernet cable (Thicknet) is used in
  the 10Base5
  Ethernet specification
• Called RG-8 (Radio Grade) cable
• 10Base5
• 10 means that data is transferred at 10 Mbps
• Base refers to baseband signaling
• 5 means the maximum length of the cable is 500
  meters
• Uses a bus topology where all devices attach to a
  single cable
• Computers are connected one to another
• Every computer receives every packet of
  information

13
CSMA/CD

• Carrier Sense Multiple Access/Collision Detection
  (CSMA/CD) is a method used by computers to share
  the same cable
• If two computers talk (try to send data) at the
  same time, a collision results that corrupts the
  data

14
CSMA/CD

• To prevent collisions when there is multiple
  access to a cable, computers first do a carrier
  sense (listen to the cable for traffic) before
  trying to send data

15
CSMA/CD

• Even though the computers listen before sending
  data, it is possible that two computers listened
  at about the same time, heard nothing, and then
  sent data resulting in a collision
• Computer NICs have collision detection circuitry
  that alerts them to a collision

16
Reflection and Termination

• Signals traveling along a wire will bounce back
  when they get to the end called reflection
• As a result a terminator is installed on the ends
  of the cable to absorb the signal to prevent it
  from reflecting back which would corrupt the
  signal

17
Connections

• Thicknet cable is marked every 2.5 meters
• Devices are connected only at these marks by
  using a vampire connector that pierces the cable
  to make a connection
• It is also a transceiver that transmits and
  receives data, sometimes called an access unit
  interface (AUI) that connects to a Digital,
  Intel, Xerox (DIX) connector
• Thicknet uses a bus topology
• If theres a break in the cable, the whole
  network goes down

18
Thicknet Connections
19
Thin Ethernet 10Base2

• Thin Ethernet is also known as
  Thinnet
• Uses RG-58 coax cable
• Limited to 30 devices per
  segment
• Cable length limited to 185 meters
• Thinner and cheaper than Thicknet
• Transceiver is built into the network card
• Uses twist-on BNC connectors
• Uses terminators

20
UTP Ethernet 10BaseT

• Modern networks use UTP Ethernet
• Modern networks do not use Thicknet or Thinnet
• 10BaseT runs at 10 Mbps
• 100BaseT runs at 100 Mbps
• 1000BaseT (Gigabit) runs at 1000 Mbps
• Use a star bus topology
• Uses unshielded twisted pair (UTP) cabling

21
Star Bus Topology

• Most common topology used is a star bus
• In a star topology all devices are connected to a
  central device called a hub
• Multiple hubs are connected together in a bus
  topology
• Together they form a star bus topology
• Hubs have been replaced by switches that conserve
  bandwidth

22
Unshielded Twisted Pair

• UTP is the predominant type of cabling used today
• Pairs of wires are twisted together in an
  unshielded cable
• UTP cables come in categories (CATs) that define
  the maximum speed at which data can be
  transferred (called bandwidth)
• CAT5, CAT5e, and CAT6 are most common today

23
Implementing 10BaseT

• Requires at least two pairs of wires one for
  receiving and one for sending
• Cables use special RJ-45 connectors
• The Telecommunications Industry Assciation/
  Electronics Industries Alliance (TIA/EIA) has two
  standards for connecting the RJ-45 connectors
• TIA/EIA 568A and TIA/EIA 568B
• Use either just be consistent
• Wires are color-coded

24
Combo Cards

• All Ethernet networks share the same language
• Many NICs will run at either 10 or 100 Mbps
• Some NICs have both BNC and RJ-45 ports

25
Hubs and Switches

• Each PC is connected to a hub or switch in a
  10BaseT network
• To add a device, just run another cable to the
  hub or switch from the device
• The maximum separation between the device and the
  hub or switch is 100 meters
• Hubs act as a repeater that regenerates the
  signal before it sends it back out other ports
• Hubs come in 4, 8, 16, or 24 ports

26
Duplex and Half-Duplex

• Modern NICs can both send and receive data at the
  same time called full duplex
• Older NICs could send and receive data but not at
  the same time called half duplex
• NICs and switches use autosensing to decide how
  to operate

27
Fiber Optic Ethernet

• Fiber optic cable uses light instead of
  electricity
• Immune to electrical interference
• Signals can travel up to 2,000 meters
• Most Ethernet uses 62.5/125 multimode cable
• Uses two cables
• Uses SC (square-shaped) or ST (round) connectors
• Common standards are 10BaseFL and
  100BaseFX
• Usually reserved for the backbone due to
  its expense

28
Token Ring

• Developed by IBM
• Uses a star ring topology
• Incompatible with Ethernet
• Data travels in a ring
• Uses token passing
• A free token circulates the ring
• A device may send data only when it
  has the token

29
Implementing Token Ring

• Legacy Token Ring ran at 4 Mbps or 16 Mbps
  using IBM Type 1 cable
• Two-pair, shielded twisted pair (STP) cable
• Todays Token Ring networks may use UTP or
  STP
• STP comes in various types
• Token Ring cables use an IBM-type Data Connector
  (IDC) or Universal Data Connector (UDC) designed
  to plug into each other
• Uses a special hub called a multistation access
  unit (MSAU or MAU)

30
Parallel/Serial Connections

• All versions of Windows have software that allows
  two (and only two) PCs to connect together via
  their parallel or serial ports
• Use a crossover IEEE 1284 cable for parallel
  ports
• Use an RS-232 cable for serial ports

31
Network Operating System
32
Client/Server

• In a client/server environment one machine is
  dedicated as a resource to be shared over the
  network
• Uses a special Network Operating System (NOS)
• Optimized for sharing files and printers or other
  resources
• Protects access to the data or resources using
  security features
• Called the server
• All other machines are clients or workstations
• Novell NetWare is an enterprise level NOS

33
Peer-to-Peer

• In a peer-to-peer network all machines on the
  network may act as a client or server
• Peer-to-peer network operating systems include
• Windows 98/Me
• Windows 2000/XP
• Limited to 10 users accessing a file at one time
• Useful for small networks only
• Lacks security
• Users are part of workgroups

34
Peer-to-Peer
35
Domain-Based

• In a peer-to-peer network you must log in to each
  server you wish to access
• In a domain-based network you log into the
  network just once to access resources throughout
  the network
• Servers on the network may play one or several
  roles
• Domain Controller (holds the security database)
• File server
• Print server
• Fax server
• Remote Access Services (RAS) server
• Application server
• Web server

36
Domain Controllers

• Domain Controllers keep the security database of
  users and passwords
• Directory services are used to store user names
  and passwords
• In Windows 2000 and 2003 server, it is called
  Active Directory
• In Novell NetWare it is called NetWare Directory
  Services (NDS)

37
Administrative Tools
Administrative Tools in Windows XP Professional
Administrative Tools in Windows 2000 Server
38
Administrator Account

• The administrator account is a special user
  account that has complete and absolute power over
  the entire system
• Joining a workgroup or becoming part of a domain
  is relatively easy in any version of Windows

39
Joining a Workgroup or Domain in Windows 98
40
Protocols

• Network protocol software
• Takes the incoming data received by the network
  card
• Keeps it organized
• Sends it to the application that needs it
• Takes outgoing data from the application and
  hands it over to the NIC to be sent out over the
  network
• The most common protocols used are
• NetBEUI
• IPX/SPX
• TCP/IP
• AppleTalk

41
NetBEUI

• NetBIOS Extended User Interface (NetBEUI)
• Small size
• High speed
• Not routable
• Limited to small networks

42
IPX/SPX

• Internetwork Packet Exchange/ Sequenced Packet
  Exchange (IPX/SPX)
• Developed by Novell
• Routable
• NWLink is Microsofts version

43
TCP/IP

• Transmission Control Protocol/Internet Protocol
  (TCP/IP)
• Developed by the U.S. Department of Defense
• Used in networks of all sizes
• Used on the Internet

44
AppleTalk

• AppleTalk is a proprietary protocol developed by
  Apple
• Used to communicate with older Apple Computers
• Apples Macintosh OS X supports TCP/IP

45
Client and Server Software

• Client software
• Needed to access data and resources on a network
• Windows installs Client for Microsoft Networks

• Server software
• Any Windows PC may be turned into a server by
  enabling sharing of files, folders, and printers

46
Installing and Configuring a Wired Network
47
Network Connectivity

• To connect to a network you need
• Network Interface Card
• Physical hardware that connects the PC to the
  network wire
• Protocol
• The language the devices will use to communicate
• Network Client
• Allows the computer system to speak to the
  protocol
• In addition, if you would like share your files
  or printer, you need to enable Microsofts File
  and Print Sharing

48
Installing a NIC

• When choosing a NIC there are three requirements
• Must run at the proper speed (many NICs run at
  more than one speed)
• Must be for the proper technology
• Ethernet, Token Ring, Fiber optic (FDDI)
• Must fit into your expansion slot
• ISA, PCI
• If your NIC does not autoinstall, then use the
  Add Hardware wizard in Control Panel

49
Configuring a Network Client

• You need a network client for each type of server
  NOS
• Client for Microsoft Networks
• Alt-click My Network Places (or Network
  Neighborhood) and choose Properties
• Double-click the Local Area Connection icon (or
  choose to Create a New Network Connection) and
  choose Properties
• Client for Microsoft Networks is automatically
  installed when you install a NIC in Windows
• Client Service for NetWare
• Provides access to file and print services on
  NetWare servers

50
Client for Microsoft Networks
51
NetBEUI

• NetBEUI
• Windows 2000 Start ?Settings ?Network and Dialup
  Connections ?Double-click the Local Area
  Connection icon
• Windows 9x/Me Start ?Settings ?Control Panel
  ?double-click the Network applet
• Click the Properties button
• Install button ?highlight Protocols and click Add
  ?NetBEUI
• Windows XP has dropped support for NetBEUI

52
NetBEUI
53
NWLink

• Microsofts implementation of IPX/SPX
• Youll also need to install Client Services for
  NetWare
• Install the same way you install NetBEUI but
  choose NWLink instead

54
Configuring TCP/IP

• TCP/IP is the most widely used protocol stack in
  networks today
• It is the protocol of choice for the Internet but
  may also be used on small private networks
• TCP/IP is installed just like NetBEUI and NWLink
  just choose Internet Protocol (TCP/IP)
• Youll need to configure and IP address and a
  Subnet Mask at the very least

55
IP Addresses

• Part of an IP address represents the network or
  subnet (network ID), while the other part
  represents the individual device (host ID) on
  that given network or subnet
• Consists of four sets of 8 binary numbers
  (octets) separated by a period
• Called dotted-decimal notation
• Examples are 10.1.209.5, 202.34.16.11
• In binary the second example is
• 11001010.00100010.00010000.00001011

56
Classes of Addresses

• IP addresses are broken into classes based on the
  size of the network
• Class A IP addresses are for large companies
• The first 8 bits or octet is used to define the
  network
• The other 3 octets are used to define the hosts
• The first octet begins with 0
• Class B IP addresses are for medium size
  companies
• The first two octets define the network
• The last two octets define the hosts on each
  network
• The first octet begins with 10
• Class C IP addresses are for smaller companies
• The first three octets define the network
• The last octet defines the host
• The first octet begins with 110

57
Classes of IP Addresses

• Some addresses are reserved
• 127.0.0.1 (the loopback address) is reserved for
  testing
• Three ranges are reserved for private networks
• 10.0.0.1 thru 10.255.255.255.254
• 172.16.0.1 thru 172.31.255.254
• 192.168.0.0 thru 192.168.255.254
• One range is reserved for Automatic Private IP
  Addressing
• 169.254.0.1 thru 169.254.255.254

58
Classes of IP Addresses
59
Subnet Mask

• The subnet mask defines which portion of the IP
  address belongs to the network ID and which part
  belongs to the host ID
• Expressed as a 32-bit number starting with 1s and
  ending with 0s
• 1s represent a network ID bit and 0s represent a
  host ID bit
• For example, 11111111.00000000.00000000.0000000
  means that the first 8 bits define the network ID
  and the last 24 bits define the host ID
• It is associated with an IP address

60
TCP/IP Services

• TCP/IP is an entire suite of protocols that
  offers TCP/IP Services such as
• Hypertext Transfer Protocol (HTTP) used on the
  World Wide Web
• Telnet used to access remote systems
• Ping to check communication
• TCP/IP is used to link multiple networks (Local
  Area Networks or LANs) with other networks to
  form an entire Wide Area Network (WAN)
• Routers are used to route traffic among the LANs

61
PING, LAN and WAN
62
TCP/IP Settings

• IP address
• Subnet Mask
• Default Gateway
• The address of a machine (usually a router) that
  will deliver messages to hosts outside of your
  local segment or subnet

63
TCP/IP Settings

• Domain Name Service (DNS)
• To reach any host on a TCP/IP network you need to
  know the IP address
• Instead of remembering IP addresses you may
  simply remember a user-friendly name
• DNS is a table that equates user-friendly names
  to actual IP addresses

64
TCP/IP Settings

• Dynamic Host Configuration Protocol (DHCP)
• Instead of manually configuring the
  TCP/IP settings on each computer
  (static settings), you may
  configure one computer to manage
  the assignments for you
• Computers that handle this use DHCP and
  are called DHCP servers
• On the client computer just choose
  to Obtain an IP address
  automatically

65
TCP/IP Settings

• Windows Internet Name Service (WINS)
• Enables Windows network names to be correlated to
  IP addresses (like DNS does for Internet names)
• Define the IP address of the WINS server
• Windows 2000/XP uses a dynamic DNS instead of
  WINS

66
TCP/IP Tools Ping

• Ping
• Tests connectivity to a remote host

67
TCP/IP Tools WINIPCFG

• WINIPCFG
• Displays your TCP/IP settings in Windows 9x/Me
• Release and Renew allows you to get new TCP/IP
  information from a DHCP server

68
TCP/IP Tools ipconfig

• IPCONFIG
• Displays your TCP/IP settings in Windows
  NT/2000/XP
• Release and Renew allows you to get new TCP/IP
  information from a DHCP server

69
TCP/IP Tools nslookup

• NSLOOKUP
• Determines the name of a DNS server among other
  things
• Type exit to return to the command prompt

70
TCP/IP Tools tracert

• TRACERT
• Shows the route a packet takes to its destination

71
TCP/IP Tools APIPA

• Automatic Private IP Addressing (APIPA)
• When a client cannot obtain an IP address
  automatically, Windows 2000/XP will automatically
  assign its own IP address from the range
  169.254.0.0 thru 169.254.255.254 with a subnet
  mask of 255.255.0.0
• APIPA is of value when a DHCP server is not
  available it allows the hosts on the LAN to
  talk to each other even though they cant reach
  anyone outside their LAN

72
Sharing Drives and Folders

• To share a drive or folder, alt-click it and
  select Sharing
• Share name is the name others will see on the
  network
• Windows 9x/Me allows you to define what a user
  may do Read Only, Full, or Depends on Password
• Windows NT/2000/XP using NTFS-formatted drives
  allows for much greater and precise control
• Set the network (Sharing tab) permissions to Full
  Control
• Then use NTFS permissions (Security tab) to
  exercise more precise control over who accesses
  the shared resource and how they access them

73
Sharing Drives and Folders
74
Accessing Shared Resources

• Access shared drives or folders using Network
  Neighborhood (Windows NT and 9x) or My Network
  Places (Windows Me, 2000, XP)
• You may also map a drive letter to a shared drive
  or folder
• Windows 2000 allows you to add a network icon
  instead of using a drive letter
• Windows XP adds a menu option

75
UNC

• Universal Naming Convention (UNC) allows you to
  access network resources as follows

\\SERVER1\FREDC
Computer name
Share name
76
Sharing Printers

• To share a printer, just alt-click on the printer
  and choose Sharing
• To access the printer, use the Add Printer icon
  and select Network printer instead of Local
  printer

77
Installing and Configuring a Wireless Network
78
Introduction

• Wireless networks are growing in popularity
• Instead of cables, wireless networks use either
  radio waves or beams of infrared light to
  communicate with each other
• Most of todays wireless networks are based on
  the IEEE 802.11 standard

79
Infrared Connections

• Infrared transceiver ports are standard on many
  portable computer, PDAs, and high-end printers
• Used to connect local devices to each other
  without using a cable

80
Wireless Networking Components

• Connection components for wider access
• PCI cards that accept wireless PC cards
• External USB wireless NICs

81
Wireless Access Point

• Wireless Access Point (WAP)
• Acts like a hub to the wireless hosts in the area

82
Wireless Networking Software

• Wireless devices use the same networking clients
  and protocol as wired networks
• Use CSMA/CD but have difficulty detecting data
  collisions
• Another option is using Request to Send/Clear to
  Send (RTS/CTS) where the sending node issues an
  RTS to the receiving node, who replies with a CTS
• Wireless networking software is PnP
• Use a utility (usually provided with the wireless
  NIC or built into Windows) to configure the
  Service Set Identifier (SSID), or network name

83
Wireless Configuration Utility
84
Wireless Network Modes

• Ad hoc Mode
• Each wireless node is in direct contact with each
  other in a decentralized free-for-all
• Form an Independent Basic Service Set (IBSS)
• Called peer-to-peer mode
• Good for a few computers or temporary network

85
Wireless Network Modes

• Infrastructure Mode
• Use one or more WAPs to connect wireless nodes to
  a wired network segment
• A single WAP is called a Basic Service Set (BSS)
• Additional WAPs create an Extended Basic Service
  Set (EBSS)

86
Wireless Networking Security

• Service Set Identifier (SSID)
• Configure a unique SSID or network name
• Each node needs to have the same SSID
• Not very secure but better than nothing
• MAC Filtering
• Filtering based on each hosts MAC address burned
  into their NIC
• Creates a type of accepted user

87
Wireless Network Security

• Wireless Equivalency Privacy (WEP)
• Encrypts data using 40-bit or 104-bit encryption
• Provides authentication based on MAC addresses
  but not users
• Encrypts only OSI layers 1 and 2
• Wi-Fi Protected Access (WPA)
• User authentication using the Extensible
  Authentication Protocol (EAP)
• Uses encryption key integrity-checking
• IEEE 802.11i
• Upcoming new security standard

88
Wireless Networking Standards

• IEEE 802.11-Based Wireless Networking
• Wireless Ethernet standard using spread-spectrum
  radio waves
• Broadcast and receive at 2.4 GHz
• 802.11a uses 5 GHz
• The original standard has been extended to form
  the Shared Wireless Access Protocol (SWAP) used
  in HomeRF networks

89
802.11 Standards
90
Wireless Network Standards

• Infrared Wireless Networking
• Simple way to share data without adding any
  additional hardware or software
• Uses the Infrared Data Association (IrDA)
  protocol
• Included in Windows 95 and higher
• Line-of-sight required
• No authentication or encryption
• But then you cant be over 1 meter away

91
Configuring Wireless Networks

• Physically installing a wireless NIC is the same
  as installing a wired NIC
• Install the wireless network configuration
  utility to configure additional parameters
• Windows XP has configuration parameters built-in
• The more important issue is authentication and
  security

92
Configuring Wireless Networks

• Wi-Fi and HomeRF
• Ad hoc
• Each wireless node needs to be configured with
  the same network name (SSID)
• May need to select a common channel
• Configure unique host IP addresses
• Configure File and Printer Sharing
• Infrastructure modes
• Requires a wireless access point (WAP)
• All nodes need to be configured with the same
  SSID
• Configure the WAP with clients that match the
  chosen options

93
Configuring Wireless Networks
94
Configuring Wireless Networks

• Configuring a Wireless Access Point (WAP) is
  usually done through a web browser
• Enter the WAPs default IP address (see your
  documentation or try 192.168.1.1) in your browser
• Enter the default administrative password (in
  your documentation) to log in
• The next few slides show some screen shots of the
  configuration pages

95
Configuring Wireless Networks
96
Configuring Wireless Networks
97
Configuring Wireless Networks
98
Configuring Wireless Networks

• Encryption screen on client wireless network
  adapter configuration utility

99
Configuring Wireless Networks

• Infrared
• About the only thing to do is to confirm in your
  network protocol configuration screen that you
  have the IrDA protocol installed and enabled
• To transfer files just alt-click the file in
  Windows Explorer and choose Send To Infrared
  Recipient
• To network two computers just choose Connect
  Directly to Another Computer when choosing the
  connection type

100
Connecting to the Internet
101
Ways of Connecting

• Dial-up
• Analog
• ISDN
• Dedicated
• DSL
• Cable
• LAN
• Wireless
• Satellite

102
Dial-up Requires a Modem

• The term modem is an abbreviation for
  modulator/demodulator
• Enables computers to communicate with each other
  via standard telephone lines
• Convert analog signals into digital signals that
  can be understood by the PCs COM ports
• Convert digital signals from the PCs COM ports
  into analog signals for standard telephone lines
• Transmit data as a series of individual 1s
  and 0s serial communication

103
Serial and Parallel Communication

• Serial Communication
• Transmits data as a series of 1s and 0s

• Parallel Communication
• Transmits data in discrete 8-bit chunks

104
UART Chip

• Both internal and external modems convert data
  between analog and digital
• CPUs must receive data in 8-bit parallel chunks
• Serial bits are converted into 8-bit parallel by
  the Universal Asynchronous Receiver/ Transmitter
  (UART) chip

105
UARTS on Modems
106
Baud Rate

• Baud rate is the basic cycle of time that a modem
  uses as its carrier frequency
• The modem speed is measured in bits per second
  (bps)
• A 2400 baud rate modem that transmits 2 bits per
  time cycle has a speed of 4800 bits per second

107
Communication Standards

• Current V standards for modems, which include
  modem speed, data compression, error correction,
  and fax were set by the International
  Telecommunication Union Telecommunications
  Standardization Sector (ITU-T)
• Current standards include V.90 and V.92
• Download speeds of about 56 Kbps
• Upload speeds of 33.6 Kbps and 48 Kbps

108
Flow Control (Handshaking)

• Flow control, also known as handshaking, is the
  process by which two serial devices manage a
  conversation
• PCs handle local flow control using hardware or
  software

109
Flow Control (Handshaking)

• Hardware flow control uses extra wires called
  ready to send (RTS) and clear to send (CTS)
• Called RTS/CTS
• When in doubt, use hardware flow control

• Software flow control uses special characters
  called XON and XOFF to signal the beginning and
  end of data transmission respectively
• Called XON/XOFF
• Slower than hardware flow control and rarely used
  today

110
Modem Connections

• Modems connect to the PC in one of two ways
• Internal modems connect to a PCI expansion slot
• External modems connect thru a serial port or a
  USB port

111
Dial-up Networking

• Dial-up networking
• Uses information from your ISP such as the
  dial-up phone number, username, password, and
  other special configuration parameters
• To configure in Windows XP select Network and
  Internet Connections in Control Panel, then
  select Set up or change your Internet connection
  and follow the wizard
• Uses Point-to-Point Protocol (PPP)

112
ISDN

• Integrated Services Digital Network (ISDN)
• Phone companies have upgraded their network
  infrastructure to all digital lines except for
  the line from your phone to the central office
• To meet the demand for higher speed access to the
  Internet, phone companies began offering ISDN
  service
• ISDN makes that last mile from your phone to the
  phone companys Central Office digital as well

113
DSL

• Digital Subscriber Line (DSL)
• Uses a regular phone line
• Needs special equipment at both ends
• Much faster than dial-up
• Upload 384 Kbps
• Download 2 Mbps
• Installation requires a NIC and DSL receiver
  (called a DSL modem) and proper
  TCP/IP settings
• Must be within 18,0000 feet from
  the closest frame

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Cable

• Cable
• Uses cable TV connections
• Very fast speedsas fast as DSL or faster
• Installation involves connecting the RG-6 or
  RG-59 coaxial cable coming in for cable TV to a
  cable modem to a NIC in the PC
• Bandwidth is shared with other users which could
  affect performance

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Other Internet Connections

• LANs
• Most companies connect their network to the
  Internet thru an ISP
• Users connect thru the local LAN
• Wireless
• Wireless connections are great when they work,
  but the technology isnt quite there yet
• Security may be an issue
• Satellite
• Uploads used to require a modem but not anymore
• Initial connections still must be made thru a
  modem

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Troubleshooting Networks
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Troubleshooting Networks

• Verify the symptom
• Talk with the use to try to get a solid
  description of the symptoms
• When did it happen?
• Does it happen a boot, when the OS loads, or
  after the system has been running for awhile?
• What has changed?
• Try to find out if anything has changed even
  recent changes before the problem began occurring

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Troubleshooting Networks

• Check the environment
• Heat, humidity, dirt
• What OS? What applications? Do others use the
  computer?
• Reproduce the problem
• If a problem happens only once, its not a
  problem
• Otherwise, try to make the problem happen again
• Isolate the symptom
• With hardware remove parts until you find the
  suspect one
• With software remove background programs or boot
  into Safe Mode

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Troubleshooting Networks

• Separate hardware from software
• Replace the suspect hardware with known good
  hardware if that doesnt solve the problem,
  then its probably software related
• Uninstall the suspect software and reinstall it
• Install the latest patch or upgrade
• Check for viruses
• Research
• Use the Internet as a great tool
• Make the fix and test
• Keep track of what you did so that you may return
  to the previous state if the fix does not work

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Mikes Four-Layer Model

• Hardware
• Check the hardware starting with the physical
  layer
• Protocols
• Is it installed and configured properly?
• Network
• Servers and non-servers
• Check users and groups, share names
• Shared resources
• Make sure the resource has been properly shared
• Check the access allowed

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Bluetooth

• Bluetooth is designed to replace all those cables
  connecting peripheral devices together
  keyboards, mouse, printer, speakers, scanner
• Acceptable for quick file transfers
• Acceptable for browsing the Internet
• Hardware comes integrated on most new portable
  electronic devices or as an internal or external
  adapter
• Configuration is PnP
• Bluetooth access points use a web browser for
  configuration

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