This document provides an overview of basic computer networks. It discusses LANs and their advantages such as simple and inexpensive connections. It describes common LAN topologies like bus, star, and ring configurations. Components of LANs such as hubs, switches, routers and their functions are explained. The document also covers wireless LANs, Wi-Fi standards, and wireless networking components including access points. Common network protocols like IP addressing, DHCP, DNS are summarized. Methods for configuring networks in Windows and connecting wireless devices are outlined.

1. 1
Basic Computer Network

2. 2
Basic Computer Network
LAN Overview
LANs were created to save time, money, and enable users to
share information and resources more easily. Some advantages
that LANs provide include
Simple and inexpensive connections
Support for multiple media protocols
Flexibility to provide any-to-any connections
Support for new applications
Ability to grow easily

3. 3
Basic Computer Network
Outside
resourcesFirewall Gateway
DMZ
Data network
LAN WAN
ServerServer
PrinterPrinter
Hub/Switch
Media
PC Workstation/ClientsPC Workstation/Clients
LAN

4. 4
Basic Computer Network
Thicknet
Thinnet
LAN Media
Fiber Optic

5. 5
Basic Computer Network
LAN Media
RJ-45STP : Shielded Twisted Pair
UTP : Unshielded Twisted Pair

6. 6
Basic Computer Network
BNC connector
LAN Adaptor
RJ-45 connector
NIC : Network Interface Card
PCI : Peripheral Component Interconnect Cards

7. 7
Basic Computer Network
MAC Addressing
• Aka Hardware address
• “Ethernet” (or 802.3) networks specify a 48-bit
physical “MAC address”
– 00-00-f8-75-5b-a6 -- Unique identifier for the network
interface card (NIC)
– Address ranges are assigned to specific vendors e.g.,
“00-00” is Digital Equipment corp.
– To find vendors MAC addresses
http://coffer.com/mac_find/
• Specific MAC address that means “broadcast”
– ff-ff-ff-ff-ff-ff (All 1s)

8. 8
Basic Computer Network
Hub
Switch
LAN Connecting Devices

9. 9
Basic Computer Network
HUB
• HUBs: F F
F F F F F F
• F ˈ 2 1 "Passive HUBs F F
F F F 2 Active HUBs F F
F F F
HUBs F 1 OSI Model

10. 10
Basic Computer Network
Switch
• Switches: F F HUBs F
F F F F F
F
• Hubs F F
F F F
Switches F F 2 OSI Model ( F
LANs Topology )

11. 11
Basic Computer Network
Router
• Router: F F F F F
F LANs – WANs WANs – WANs
F F Router F
F F F F F (Internetworking
Device)
• F F F Router F IP F
3 OSI Model
TOT’s NETWORK

12. 12
Basic Computer Network
LAN Topologies
BUS
STAR RING
• Bus
• Ring
• Star
• Star-Bus

13. 13
Basic Computer Network
Star-Bus Topology

14. 14
Basic Computer Network
F
Gigabit
Ethernet
system
IEEE 802.3ae
F Gigabit
Ethernet system
IEEE
802.3z/802.3ab
F
Fast Ethernet
system
IEEE 802.3u
F
.........
IEEE
802.3
10 Gbps1000 Mbps100 Mbps10 Mbps
ETHERNET
IEEE802.3

15. 15
Basic Computer Network
Fast Ethernet
Twisted Pair
(UTP)
.........100 Mbps100baseT
Fiber Optic200010 Mbps10baseF
Twisted Pair
(UTP)
STAR10010 Mbps10baseT
Thick EthernetThick Coaxial50010 Mbps10base5
Thin Ethernet
Cheapernet
Thin CoaxialBUS185 - 20010 Mbps10base2
F
Cable
Topology
F
- F
F
- F
FF
F ETHERNET

16. 16
Basic Computer Network
IP Address
Internet Protocol Address ˈ F F F F
F F F Hardware F
– F F F (Host Address)
– F F (Network Address)
• 32 bit F ˈ 4 F F F F F 0- 255

17. 17
Basic Computer Network

18. 18
Basic Computer Network
IP Addresses – Class A
• Class A
– Start with binary 0
– All 0 reserved
– 01111111 (127) reserved for loopback
– Range 1.x.x.x to 126.x.x.x
– All allocated
• Private address 10.x.x.x

19. 19
Basic Computer Network
IP Addresses – Class B
• Start with binary 10
– Range 128.x.x.x to 191.x.x.x
– Second Octet also included in network address
– 214 = 16,384 class B addresses
– All allocated
• Private address range
172.16.x.x – 172.31.x.x

20. 20
Basic Computer Network
IP Addresses – Class C
• Start with binary 110
– Range 192.x.x.x to 223.x.x.x
– Second and third Octet also part of network address
– 221 = 2,097,152 class C addresses
– Near all allocated
• Private address range
192.168.x.x

21. 21
Basic Computer Network

22. 22
Basic Computer Network
Dynamic Host Configuration ProtocolDynamic Host Configuration Protocol
• DHCP Service F IP Address
F F F (Client) F F F F
F F F Client F
F F (Server) F Service F F
run F F Client F F F IP
F

23. 23
Basic Computer Network
Domain Name
(Domain Name) ˈ
F (IP Address) ˈ
F F F
F F IP 202.44.204.33
" " ˈ www.nectec.or.th
F F F F F IP Address
F ˈ Lookup ʽ
ˈ (Domain Name) F Domain Name
Server

24. 24
Basic Computer Network
F F
F Network
Windows 98 / ME

25. 25
Basic Computer Network
setup windows 98/ME
Click My computer Properties
Network Interface Card
Network Interface Card

26. 26
Basic Computer Network
setup windows 98/ME
• start
• Setting
• Control Panel

27. 27
Basic Computer Network
setup windows 98
• ʽ Control Panel Network

28. 28
Basic Computer Network
Network Configuration
1
2

29. 29
Basic Computer Network
TCP/IP Properties : IP Address

30. 30
Basic Computer Network
DNS Configuration

31. 31
Basic Computer Network
• F F PC Network
F DOS Prompt F F ipconfig /all

32. 32
Basic Computer Network
RUN F winipcfg

33. 33
Basic Computer Network
F F
F Network
Windows XP / 2000

34. 34
Basic Computer Network
1. Icon My network Place F Properties
Setup Windows XP / 2000

35. 35
Basic Computer Network
2. Local Area connection F Properties

36. 36
Basic Computer Network
3. Double Click Internet Protocol (TCP/IP)

37. 37
Basic Computer Network
4. Obtain an IP automatically, Obtain DNS server automatically

38. 38
Basic Computer Network
Setup F Control Panel
Control Panel

39. 39
Basic Computer Network
Double Click Network Connections
Double Click
Network
Connections

40. 40
Basic Computer Network
Local Area Connection Properties
Click
Properties

41. 41
Basic Computer Network
Internet Protocol (TCP/IP) ˁ Properties F
General F Obtain an IP address automatically Obtain DNS
server address automatically.
internet
Protocol(TCP/IP)
obtain an IP address
obtain DNS
Click Properties

42. 42
Basic Computer Network
• F F PC Network
F DOS Prompt F F ipconfig /all

43. 43
Basic Computer Network
F PingF Ping
• F F F F
F F F ICMP
(Internet Control Message Protocol)
F F ˈ ICMP Echo
Reply ( F ˈ ICMP Echo Request)
• block ping F F Fire wall
F F F ˈ F F
F F

44. 44
Basic Computer Network
ʽ command prompt F Ping
F IP address F F

45. 45
Basic Computer Network
Wireless LANWireless LAN

46. 46
Basic Computer Network
F Wireless LAN (Local Area Network) WLAN
ˈ F F F peer-to-
peer F F (station) F
F ˈ F F (point-
to-point) F (point-to-multi point)
F WLAN ˈ F F LAN
F ˈ F F
LAN F F
F Wireless LAN

47. 47
Basic Computer Network
F F
F F F F F
F F F F
F F F F F F
F F F F

48. 48
Basic Computer Network
F F F
Wireless LAN (Proprietary)
Wired LAN Network
IEEE Standard ETSI Standard
IEEE 802.11
IEEE: Institute of Electrical and Electronics Engineers
ETSI: European Telecommunications Standards Institute
HiperLAN/1
HiperLAN/2
HiperACCESS
IEEE 802.11b (Wi-Fi) IEEE 802.11a (Wi-Fi5)
IEEE 802.11g (Wi-Fi)

49. 49
Basic Computer Network
IEEE 802.11Specifications
2.4-2.497 GHz
5.15-5.35 GHz
5.425-5.675 GHz
2.4-2.497 GHz
Frequencies
CCK= 1,2,5.5,11
Mbps
OFDM=6,9,12,18,2
4,36,48,54 Mbps
6,9,12,18,24,36,
48,54 Mbps
1,2,5.5,11 Mbps
Data rates
OFDM and CCKOFDMCCKModulation
54Mbps54Mbps11MbpsMaximum
Data rate
June 2003July 1999July 1999Standard
Approved
802.11g802.11a802.11b
OFDM (Orthogonal Frequency Division Multiplexing)
CCK (Complementary Code Keying)

50. 50
Basic Computer Network
Wi-Fi
Wi-Fi F F Wireless Fidelity ˈ
F F F
IEEE 802.11 (Institute of Electrical and Electronic
Engineer 802.11)
F F F
F F (Wireless Local Area Network
(WLAN)) F F UHF (Ultra High
Frequency)

51. 51
Basic Computer Network
Wireless Network Components
RF interface for
iPAQ / Casiopia)
Access Point
………….……. …
…
…
…
…
…
…
.
…
…
…
…
…
…
…
…
.…
.
RF interface for
desktop PC
RF interface for
notebook

52. 52
Basic Computer Network
Access Point
ˈ F Wireless Network
ˈ
- F F
F F F F F
128
F F MAC
address
F F F
Client mode, Infrastructure, Repeater,
Multipoint repeater

53. 53
Basic Computer Network
RF Interface Card
F PCMCIA USB port
Card Compact flash
F PCMCIA F F PCI F PCI Wireless F F F PCMCIA
PCMCIA : Personal Computer Memory Card International Association

54. 54
Basic Computer Network
F F
F Wi-Fi F
F F F
F F F IEEE 802.11a/b/g

55. 55
Basic Computer Network
Wireless Bridging
(LAN-to-LAN connectivity)Infrastructure connection
Ad- hoc connection
F F WLAN

56. 56
Basic Computer Network
Peer to Peer Topology (AdPeer to Peer Topology (AdPeer to Peer Topology (AdPeer to Peer Topology (Ad hochochochoc))))
o F F F F Access Point
o F F ( F 3 )
o F F
AdAdAdAd----hoc network is a network typically created in a spontaneous mannhoc network is a network typically created in a spontaneous mannhoc network is a network typically created in a spontaneous mannhoc network is a network typically created in a spontaneous manner.er.er.er.

57. 57
Basic Computer Network
F Infrastructure F Access Point
F F F F F
F
F F

58. 58
Basic Computer Network
F Infrastructure FAccess Point
ˈ F
F Access point
Access point F F F F F Roaming

59. 59
Basic Computer Network
Channels - IEEE802.11 DS
o 3 F F F /
o Access Points F 3
o F F bandwidth F F 22 MHz.
o F F 11 Mb/s
1 2 3 4 5 6 7 8 9 10 11
2400
24722412
12 13
1
2
3
5
4
6
7
8
10
9
13
11
12

60. 60
Basic Computer Network
Service Set Identifier (SSID)
• F Service Set
• ˈ F F F
• F F F F F
ˈ

61. 61
Basic Computer Network
Wired Equivalent Privacy
(WEP)
• F
Ac-Hoc
• ʽ
• F WEP 64 F F 10 digit
• F WEP 128 F F 26 digit

62. 62
Basic Computer Network
Local Area Network (LAN)
HubHubHubHub
ServerServerServerServer SwitchSwitchSwitchSwitch
InternetInternetInternetInternet
Access PointAccess PointAccess PointAccess PointHubHubHubHub
Wireless LAN (WLAN) as anWireless LAN (WLAN) as anWireless LAN (WLAN) as anWireless LAN (WLAN) as an
extension to wired LANextension to wired LANextension to wired LANextension to wired LAN
Ethernet ClientEthernet ClientEthernet ClientEthernet Client

63. 63
Basic Computer Network
1. F ( PC F ) F F
F
PCMCIA F PCI F PCI
Slot F
PCI Wireless F F F PCMCIA PCI Slot
F
USB F F USB F ( USB
F F F F F F )
F F F F

64. 64
Basic Computer Network
2. F F F F F F
PCMCIA F F F F F F Centrino
USB F F USB F F
3. F F F Centrino F ˈ F F F
F F Centrino F F F
F
4. F Palm Pocket PC F F F
F F F Palm Pocket
PC F F F
F F F F

65. 65
Basic Computer Network
DELL

66. 66
Basic Computer Network
Hewlett Packard

67. 67
Basic Computer Network
IBM

68. 68
Basic Computer Network
ACER

69. 69
Basic Computer Network
Compaq

70. 70
Basic Computer Network
Compaq

71. 71
Basic Computer Network
ASUS

72. 72
Basic Computer Network
THE ENDTHE END
Q & AQ & A