Telecommunications systemsand networking
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The document discusses telecommunications and networking concepts including: 1. It defines networks and their value, identifies trends in telecommunications industries and technologies. 2. It explains components of telecommunications networks like hardware, software, and services. The concepts of client/server networking are also introduced. 3. Major developments in digital network technologies, internet networking, and wireless technologies are described. These trends have increased transmission speeds and network capacity.
Telecommunications systemsand networking
- 1. Telecommunications Systems and Networking 1
- 2. Learning Objectives • Understand the concept of a network • Apply Metcalfe’s law in understanding the value of a network • Identify major developments and trends in the industries, technologies, and business applications of telecommunications and Internet technologies • Provide examples of the business value of Internet, intranet, and extranet applications 2
- 3. Learning Objectives • Identify the basic components, functions, and types of telecommunications networks used in business • Explain the functions of major components of telecommunications network hardware, software, media, and services • Explain the concept of client/server networking 3
- 4. Network Concepts • A network is an interconnected or interrelated chain, group, or system • The number of possible connections on a network is N(N–1) or N2 –N – N = number of nodes (points of connection) – Example: 10 computers on a network = 10(10–1) = 10x9 = 90 possible connections 4
- 7. Value of Telecommunications Networks 7
- 8. Digital Network Technologies • Telecommunications are being revolutionized by switch from analog to digital – Analog: voice-oriented transmission – Digital: discrete pulse transmission • Benefits – Higher transmission speeds – Moves larger amounts of information – Greater economy and much lower error rates – Transmits multiple types of communications (data, voice, video) on the same circuits 8
- 9. Internet Networking Technologies • Internet networking technologies are being used as technology platform – Web browser suites – HTML Web page editors – Network management software – Firewalls • Being applied in Internet, intranet, and extranet applications • Reinforces previous move toward client/server networks based on open-systems architecture 9
- 10. Internet2 • Next generation of the Internet – High-performance – Different infrastructure than the current Internet – Will not replace the current Internet – In use at over 200 universities, scientific institutions, communications corporations – May never become totally open – Users are connected via Abilene, a backbone that supports throughput of 10 Gbps – Infinite bandwidth 10
- 11. Internet Service Providers • ISP – A company that specializes in providing easy access to the Internet – For a monthly fee, provides software, user name, password, and Internet access • ISPs themselves are connected to one another through network access points – One ISP can easily connect to another to obtain addresses of websites or user nodes 11
- 12. Internet Applications • Most popular Internet applications and uses – E-mail – Instant messaging – Browsing the Web – Newsgroups – Chat rooms – Publish opinions, subject matter, creative work – Buy and sell – Downloading (data, software, reports, pictures, music, videos) 12
- 13. Business Value of the Internet 13
- 14. The Role of Intranets • Many companies have sophisticated and widespread intranets, offering… – Detailed data retrieval – Collaboration – Personalized customer profiles – Links to the Internet • Intranets use Internet technologies – Web browsers and servers – TCP/IP network protocols – HTML publishing and databases 14
- 15. Intranets • Intranets are protected by… – Passwords – Encryption – Firewalls • Customers, suppliers, and other business partners can access an intranet via extranet links 15
- 16. Business Value of Intranets • Intranets support – Communications and collaboration – Business operations and management – Web publishing – Intranet portal management 16
- 17. Intranets as Information Portals 17
- 18. Extranets • Network links that use Internet technologies to connect the intranet of a business to the intranets of another • Virtual Private Networks – Direct private network links, or private secure Internet links between companies • Unsecured Extranet – Link between a company and others via the Internet, relying on encryption of sensitive data and firewall security systems 18
- 19. Extranet Connectivity 19
- 20. Business Value of Extranets • Web browser technology makes customer and supplier access to intranets easier and faster • Another way to build and strengthen strategic relationships • Enables and improves collaboration between a business, customers, and partners • Facilitates online, interactive product development and marketing 20
- 21. Telecommunications Network Components • Terminals – Any input/output device that uses networks to transmit or receive data • Telecommunications processors – Devices that support data transmission, reception • Telecommunications channels – Media over which data are transmitted, received • Computers – All sizes and types 21
- 22. Types of Communications Networks • Primary types of communications networks – Wide Area – Local Area – Virtual Private – Client/Server – Peer-to-peer 22
- 23. Wide Area Network (WAN) • Telecommunication network that covers a large geographic area 23
- 24. Local Area Network (LAN) • Connects computers within a limited physical area, such as an office, classroom, or building 24
- 25. Virtual Private Networks (VPN) • Used to establish secure intranets and extranets – The Internet is the main backbone network – Relies on network firewalls, encryption, and other security features to build a “pipe” through the Internet – Creates a private network without the high cost of a separate proprietary connection 25
- 26. Virtual Private Network 26
- 27. Client/Server Networks • Clients – End user personal computers or networked computers • Servers – Used to manage the networks • Processing – Shared between the clients and servers – Sometimes called a two-tier architecture • Larger computer systems are being replaced with multiple client/server networks 27
- 28. Client/Server Network 28
- 29. Network Computing • Networks are the central computing resource of the organization – Thin clients provide a browser-based user interface for processing applets • Thin clients include – Network computers – Net PCs – Other low-cost network devices or information appliances 29
- 30. Network Computing • Application and database servers provide – The operating system – Application software – Applets – Databases – Database management software • Sometimes called a three-tier client/server model because it consists of – Thin clients – Application servers – Database servers 30
- 31. Network Computing 31
- 32. Peer-to-Peer Networks • Central Server Architecture – P2P file-sharing software connects all PCs to a central server – When a PC requests a file, the server searches all active peers on the network – The server sends the requesting PC a list of links to all active peers who have the file – Clicking a link connects the two PCs and automatically transfers the file to the requesting PC 32
- 33. Peer-to-Peer Networks • Pure Peer-to-Peer Architecture – No central directory or server – File-sharing software connects one PC to another online user – When you request a file, the software searches every online user and sends you a list of active file names – Clicking a link automatically transfers the file from that user’s hard drive to yours 33
- 34. Central Server Peer-to-Peer Networks • Advantages – Can better protect the integrity and security of the content and users of the network • Disadvantages – Directory server can be slowed or overwhelmed by too many users or technical problems 34
- 36. Telecommunications Media • Twisted-Pair Wire – Ordinary telephone wire – Copper wire is twisted into pairs 36
- 37. Telecommunications Media • Coaxial Cable – Sturdy copper or aluminum wire wrapped with spacers to insulate and protect it 37
- 38. Telecommunications Media • Fiber-Optic Cable – One or more hair-thin filaments of glass fiber wrapped in a protective jacket 38
- 39. Wireless Technologies • Terrestrial Microwave – Earthbound microwave systems transmit high-speed radio signals – Follows a line-of-sight path between relay systems spaced about 30 miles apart • Communications Satellites – Serve as relay stations – Use microwave radio signals – Earth stations beam signals to the satellites – Not suitable for interactive, real-time processing 39
- 40. Wireless Technologies • Cellular and PCS Telephone and Pager Systems – Geographic areas are divided into cells – Each cell has a low-power transmitter or radio relay antenna – Computers and other communications processors coordinate and control the transmissions to and from mobile users 40
- 41. Wireless Technologies • Wireless LANS – Uses wireless radio-wave technology to connect PCs within an office or a building – Can be high-frequency, similar to digital cellular, or low frequency (spread spectrum) • Bluetooth – Short-range wireless technology – Connects PCs to devices, such as a printer – Fairly low cost to implement 41
- 42. Standard Capacity for Wireless LAN • 802.11a – standard can transmit up to 54 Mbps in the unlicensed 5 GHz frequency range and has effective distance of 10 to 30 meters. • 802.11b - standard can transmit up to 11 Mbps in the unlicensed 2.4 GHz frequency range and has effective distance of 30 to 50 meters. • 802.11g - standard can transmit up to 54 Mbps in the unlicensed 2.4 GHz • 802.11n – will transmit at more than 200 Mbps. 42
- 43. Wireless Technologies • Other Wireless Systems – Cellular phones – Mobile radio – PDAs • Telecommunications networks now play vital and pervasive roles in – Web-enabled e-business processes – Electronic commerce – Enterprise collaboration – Other applications that support business operations, management, and strategic objectives 43
- 44. The Wireless Web • Wireless Internet access is growing as Web- enabled information appliances proliferate – Smart telephones, pagers, PDAs – All are very thin clients in wireless networks 44
- 45. Network Topologies • Topology – The structure of a network • Star Network – Ties end user computers to a central computer • Ring Network – Ties local computer processors together in a ring on a relatively equal basis • Bus Network – Local processors share the same communications channel 45
- 46. Network Topologies • Mesh Network – Uses direct communications lines to connect some or all of the computers in the ring to each other • Switch – A message-switching computer that handles data communication between autonomous local computers 46
- 47. Network Topologies 47
Editor's Notes
- #44: Multimedia Lecture Support Package to Accompany Basic Marketing Lecture Script 6-