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2. Sharing of technology resourcesSharing of dataDistributed data processing and client/server systemsEnhanced communicationsMarketing outreach. . THE NEED FOR NETWORKING. Page 96-97. 3. . AN OVERVIEW OF TELECOMMUNICATIONS AND NETWORKING. Page 97-98. Networking ? the electronic linking of geogr
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1. 1 CHAPTER 4
TELECOMMUNICATIONS AND NETWORKING
2. 2 Sharing of technology resources
Sharing of data
Distributed data processing and client/server systems
Enhanced communications
Marketing outreach THE NEED FOR NETWORKING
3. 3 AN OVERVIEW OF TELECOMMUNICATIONS AND NETWORKING
4. 4
5. 5 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Analog network uses continuous voltage varying as a function of time
Example: voice over telephone lines
Digital network directly transmits two discrete states
Note: 0 for pulse off and 1 for pulse on
6. 6 KEY ELEMENTS OFTELECOMMUNICATIONS AND NETWORKING Modem
Device needed when transmitting data over analog lines
Converts data from digital to analog to be sent over analog telephone lines
Also reconverts data back to digital after data transmission
Abbreviation for modulator/demodulator
7. 7 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
8. 8 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
9. 9 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Hertz cycles per second
Baud number of signals sent per second
Bits per second (bps) number of bits sent per second
When each cycle sends one signal that transmits exactly one bit of data (often the case), then the three terms are identical
10. 10 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Switched line system
Example: public telephone system
Uses switching centers to route signals along best possible path to destination
Private (dedicated) lines
Leased from companies such as MCI, Sprint, AT&T
Use direct physical lines between source and destination
11. 11 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING Simplex data travels in one direction only
Half-duplex data can travel in both directions, but only one direction at a time
Full-duplex data travels in both directions at the same time
12. 12 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
13. 13 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
14. 14 Figure 1-6: Relative Capacities of telephone, LAN, BN, WAN, and Internet circuits. Business
Data Communications
and Networking
Fitzgerald and Dennis,
7th Edition
2002 John Wiley & Sons, Inc.
15. 15
16. 16 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
17. 17 Cordless telephone
Cellular phone
Wireless LAN Microwave
Satellite
18. 18
19. 19 Fiber-optic cabling
Newest transmission medium
Transmits data by pulses of light through thin fiber of glass
Much faster than other media
Thinner requires less space
More secure harder to tap
20. 20
21. 21
22. 22 KEY ELEMENTS OFTELECOMMUNICATIONS ANDNETWORKING
23. 23 Computer Telecommunications Networks
Private branch exchange (PBX) Networks
Local Area Networks (LANs)
Backbone Networks
Wide Area Networks (WANs)
Internet
Internet2
24. 24 Computer Telecommunications Networks
Emanates from a single medium or large computer
Usually arranged as a tree
Uses coaxial and twisted pair cabling
Controlled by central computer
Often has a front-end processor to handle all aspects of telecommunications
25. 25
26. 26 Private Branch Exchanges (PBX)
Originally analog, today usually digital
Can serve as the central device in a star or ring network
Can function as front-end processor for mainframe
27. 27 Private Branch Exchanges (PBX)
Advantages:
Can connect ALL telecommunications devices in a building or campus
Can use existing telephone wiring
Can carry voice and data over same network
Has a high-potential throughput
28. 28
29. 29 Local Area Networks
Owned by a single organization
Operate within area 2-3 miles in diameter
Contain a number of intelligent devices, usually microcomputers, that can process data based on peer-to-peer relationship
No part of telephone system, have their own wiring
30. 30 LAN Topologies and Standards
Contention bus design IEEE 802.3
Token bus design . IEEE 802.4
Token ring design IEEE 802.5
Wireless design .. IEEE 802.11
31. 31 Contention Bus Design (Ethernet)
Bus topology
Implemented with coax or twisted pair
Usually half-duplex
All devices contend for use of cable
Design now called Shared Ethernet uses a contention bus as its logical topology and implemented with a physical star arrangement
32. 32
33. 33 Switched Ethernet
Newer variation, better performance, higher price
Uses switch instead of hub
Operates both logical and physical star
Each device has own dedicated circuit
34. 34 Token Bus
Employs bus topology, no contention
Uses single token passed around to all devices in order
Device can only transmit when has token
Central to Manufacturing Automation Protocol (MAP) connects robots and other machines on assembly line by a LAN
35. 35 Token Ring
Device attached to ring must seize token before can send a message
Collisions cannot occur
Usual implementation is physical star, logical ring
36. 36 Wireless LAN
Known as Wi-Fi (wireless fidelity)
Growing in demand for corporate and home use
Use IEEE 802.11 standards with shared Ethernet design
Requires use of wireless network interface card (NIC)
Wireless Access Point (WAP) radio transceiver that acts as a hub
37. 37
38. 38 Backbone Network
In-between network that interconnects LANs in a single organization with each other and with organizations WAN and the Internet
39. 39 Backbone network terminology:
Bridge connects two LANs using same protocol
Switch connects more than two LANs using the same protocols
Router (gateway) connects two or more LANs that may use different protocols
40. 40
41. 41 Wide Area Networks (WANs)
Communicate voice and data across greater distances
Usually owned by several organizations (including user organization and common carrier)
Employ point-to-point transmission
Often rely on public telephone network
42. 42 Switched-circuit
Direct distance dialing (DDD)
Wide Area Telephone Service (WATS)
Integrated Service Digital Network (ISDN)
Dedicated-circuit
Leased lines,
T1, T2, T3, T4,
SYNCHRONOUNS Optical Network SONET
Satellite
43. 43 Leased lines,
T1, T2, T3, T4,
SYNCHRONOUNS Optical Network, SONET
Satellite
44. 44 Leased lines,
T1, 1.5 mbps
T2, (4x T1) 6.3 mbps
T3, (7 x T2 ) 45. mbps
T4, (6 x T3 ) 274 mbps
SYNCHRONOUNS Optical Network, SONET for fiber optic
OC-1, 52 mbps
.,
CO-768 40 gbps
45. 45 Loral Space and Communications
Hughes Electronic Corporation
Intelsat
VSAT
Kmart
Wal-Mart
V-Crest VW, Audi
46. 46 Packet-switched
Shared private lines using store-and-forward data transmission
Permits multiple connections to exist simultaneously over the same physical circuit
47. 47 ATM fast packet switching with short, fixed-length packets
Virtual Private Networks (VPNs) provide same as private packet-switched network using the public Internet
48. 48 The Internet
Network of networks that use the TCP/IP protocol
Contain gateways to computers that do not use TCP/IP
Provides four basic functions:
Electronic mail
Remote login
Discussion groups
Sharing of data resources
49. 49
50. 50 Internet access services:
Digital subscriber line (DSL) service offered by telephone companies using copper wire already installed in homes moving data over wires without disturbing voice traffic
Cable modem connection obtained from cable TV company using existing home coaxial cable
Satellite most expensive, but may be only option for customers in rural areas
51. 51
52. 52
53. 53 Primary goals of Internet2:
Create a leading-edge network capability for the national research community
Enable revolutionary Internet applications based on a much higher-performance Internet that we have today
Ensure the rapid transfer of new network services and applications to the broader Internet community
54. 54
55. 55 LAN protocols:
Contention bus
Token bus
Token ring
Fiber Distributed Data Interface, FDDI
Wireless
IBMs own protocol Systems Network Architecture (SNA)
56. 56 International Organization for Standardization (ISO) network protocol Open Systems Interconnection Reference Model (OSI)
Thought to become the only standard for networking
Gained momentum until Internet explosion
Transmission Control Protocol/Internet Protocol (TCP/IP)
Has become the de facto standard for networking today
57. 57
58. 58 Figure 1-3: Network Models
59. 59 Fig. 1-4 Message transmission using layers
60. 60
61. 61 Fig. 1-5. Some data communications standards
62. 62 Online Operations
Connectivity
Electronic Data Interchange (EDI) and Electronic Commerce
Marketing
63. 63 THE TELECOMMUNICATIONS INDUSTRY Carriers
Own or lease the physical plant cabling, satellites, cellular towers, etc.
Sell service of transmitting communication from one location to another
64. 64 THE TELECOMMUNICATIONS INDUSTRY Equipment vendors
Manufacture and sell LAN software and hardware
Includes routers, hubs, wireless access points, digital switches, multiplexers, cellular telephones, modems
65. 65 THE TELECOMMUNICATIONS INDUSTRY Service providers
Operate networks and deliver services through the network
Provide access to or services via the Internet (such as AOL, Microsoft Network, Yahoo!, and many ISPs