1. UNIVERSITI TENAGA NASIONAL “Generates Professionals” CHAPTER 7 : Part 2 INTRODUCTION TO NETWORKING

2. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Objectives Describe various network topology List the components, types, and protocols of a local area network Appreciate the complexity of networking Describe some examples of networking 2

3. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Network Topology The physical layout of a network Node - each computer, printer, or server on network Three common topologies –Star –Ring –Bus 3

4. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Star Topology Central (hub) computer manages network All messages routed through hub –Helps prevent collisions among messages Connection failure between hub and any node will not affect overall system –If hub is down, the network fails 4

5. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Star Topology 5 Connection (hub  node) fail Does not affect the overall system Hub fail Entire network fails B A A B

6. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Ring Topology Links all nodes in a circular chain Data messages travel around ring in a single direction –Each node checks message to see whether that node is the addressee –If not, message passed to next node No danger of data collision If one node fails, ring is broken and network fails 6

7. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Ring Topology 7 Data travel in one direction No problem with data collision One of the nodes fail Entire network fails A B A B

8. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Bus Topology All nodes connected to single line (bus) Computers send messages to other computers on network –If messages collide with other messages, sending node resends message Nodes can be added/removed from network without affecting network If a node fails, network does not fail 8 bus

9. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Bus Topology One of the nodes fail Does not affect the overall system 9 A A

10. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Wide Area Network (WAN) Networks can be classified by the geographical area they cover WAN can span the world or just link computers across town –Metropolitan Area Network (MAN) networks that cover a single city Components –Communications services –WAN hardware –WAN software 10

11. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 11 A possible networks connection LAN, WLAN and WAN Wide Area Network (WAN)

12. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Local Area Network (LAN) A collection of computers that share hardware, software, and data –Typically personal computers and within an office or building –Does not use the telephone networks LAN components –Network cable, Network interface card (NIC) –Bridge, Router, Gateway Types of LANs –Client/Server –Peer-to-peer 12

13. UNIVERSITI TENAGA NASIONAL “Generates Professionals” LAN Components Bridge  allows connection of similar networks (those using the same protocol) Router  directs communications traffic when several networks connected together –If network traffic clogged, router can redirect traffic to another route IP switch  used in place of router when networks use the Internet protocol –Less expensive and faster than routers Gateway  Lets a node communicate with a computer on another dissimilar network –Primary function is converting protocol among networks 13

14. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Client/Server LAN Server computer controls network –Often has several hard drives, fastest printer Client computer requests services from server Thin client  –a computer that has little or no disk storage ability –Send input and receive output only Processing approaches –Client/server –File server 14

15. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Client/Server Approach Client requests data from server Server passes only the requested data –Client may perform some processing, but most data processed on server 15

16. UNIVERSITI TENAGA NASIONAL “Generates Professionals” File Server Approach Client requests data from server Server sends entire file –Client performs all data entry and processing –File retransmitted to server 16

17. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 17 Centralized - Resources and data security are controlled through the server. Scalability - Any or all elements can be replaced individually as needs increase. Flexibility - New technology can be easily integrated into system. Interoperability - All components (client/network/server) work together. Accessibility - Server can be accessed remotely and across multiple platforms. Advantages of a Client/Server LAN

18. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 18 Expense - Requires initial investment in dedicated server. Maintenance - Large networks will require a staff to ensure efficient operation. Dependence - When server goes down, operations will cease across the network Disadvantages of a Client/Server LAN

19. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Peer-to-Peer LAN Small network that shares hardware, data, or information located on any other computer in network Each computer stores files on its own storage devices All computers on the network have equal status; – No one computer is in control. – There are no file servers Easy to set up; example: home networks, small offices with fewer PC 19

20. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 20 Advantages of a peer-to-peer network: –Less initial expense - No need for a dedicated server. –Setup - An operating system (such as Windows XP) already in place may only need to be reconfigured for peer-to-peer operations. Disadvantages of a peer-to-peer network: –Decentralized - No central repository for files and applications. –Security - Does not provide the security available on a client/server network Peer-to-Peer LAN

21. UNIVERSITI TENAGA NASIONAL “Generates Professionals” LAN Protocols Networks must have a set of rules/protocol  used to access the network and send data Two common protocols for LAN –Ethernet –Token Ring 21

22. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Ethernet Dominant network protocol Uses either bus or star topology Transmission method  Carrier Sense Multiple Access with Collision Detection (CSMA/CD) –Node “listens” to see when the network is available –If two computers transmit at same time, collision occurs –Network detects the collision –Each computer waits random amount of time and retransmits 22

23. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Token Ring Uses ring topology Token (electrical signal) controls which node can send messages Transmission method  Token Passing –Token circulates among nodes –A computer waits for an empty token, attaches message, and transmits Only one token, so only one device can access network at a time Larger networks allow for multiple tokens 23

24. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 24 Wi-Fi  Wireless-fidelity Wireless LAN no running cable from room to room no tacking cable to the Walls no hiding cable under the carpet no drilling Use central server or access point LAN Technologies

25. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 25 Wireless Access Point-a device that "connects" wireless communication devices together to create a wireless network. What could you actually do with Wi-fi? -share high speed Internet access, music and video files, check e-mail, or simply share a printer with others on home or work network. Advantages – Fast (11 Mbps) – Reliable – Long range – Integrates with existing networks LAN Technologies

26. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 26 Serves as a unique identifier for a computer on a network. When set up correctly, computers can determine the addresses of other computers on the network and use these addresses to send messages to each other. One of the best known form of network addressing is the Internet Protocol (IP) address. IPv4 addresses consist of four bytes (32 bits) that uniquely identify all computers on the public Internet. Network Address

27. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 27 Another popular form of network address is the Media Access Control (MAC) address. MAC addresses are six bytes (48 bits) that manufacturers of network adapters burn into their products to uniquely identify them. Network Address

28. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 28 Two versions of IP exist in production use today. Nearly all networks use IP version 4 (IPv4), but an increasing number of educational and research networks have adopted the next generation IP version 6 (IPv6). IP address199.95.72.10 first part identifies network last part identifies specific computer IP Address

29. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 29 IPv4 Addressing Notation An IPv4 address consists of four bytes (32 bits). These bytes are also known as octets. For readability purposes, humans typically work with IP addresses in a decimal notation that uses periods to separate each octet. For example, the IP address 00001010 00000000 00000000 00000001 usually appears in the equivalent dotted decimal representation 10.0.0.1 IPv4 Address

30. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 30 0000101010 00000000 0 00000001 1 2727 2626 2525 2424 23232 2121 2020 1286432168421 00001010 IPv4 Address

31. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 31 Because each byte is 8 bits in length, each octet in an IP address ranges in value from a minimum of 0 to a maximum of 255 2727 2626 2525 2424 23232 2121 2020 1286432168421 11111111 11111111 255 IPv4 Address

32. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 32 Therefore, the full range of IPv4 addresses is from 0.0.0.0 through 255.255.255.255. That represents a total of 4 billion possible IP addresses IPv6 Addressing Notation –IPv6 addresses are 16 bytes (128 bits) long rather than IPv4 addresses  four bytes (32 bits). –That represents more than 340 undecillion (340 x 10 36) possible addresses IPv6 Address

33. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 33 IPv6 addresses are generally written in the following form: hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh Pairs of IPv6 bytes are separated by a colon and each byte in turns is represented as an equivalent pair of hexadecimal numbers, like in the following example: E3D7:0000:0000:0000:51F4:9BC8:C0A8:6420 “If the address space of IPv4 is compared to a length of 1 milimeter, then IPv6 is 80 times the diameter of the galactic system” IPv6 Address

34. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 34 Using Command PromptUsing Control Panel How to Check IP Address of PC

35. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Network Uses Electronic mail (e-mail) Facsimile (fax) technology Groupware Teleconferencing Electronic data interchange Electronic fund transfers The Internet 35

36. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Internet Alternatively referred to as the net or web (World Wide Web) that gives us access to more information, entertainment and ways to communicate. It is made up of millions of computers from all around the world, linked to each other by a network of telephone lines, cables and satellite connections. It is also has thousands of services that help make life more convenient. For example, many financial institutions offer online banking that enables a user to manage and view their account online. 36

37. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Internet The Internet basics: –The Internet utilizes the TCP/IP protocol and is accessed using a computer modem, broadband, 3G or network that is connected through an ISP. ISP (Internet Service Provider) is a company that provides Internet access to users or subscribers of its service. For example TM unifi (fiber optic) and Maxis (cellular or mobile broadband) –The Internet is explored, which is more commonly referred to as surfing, using a browser. –Finding information on the Internet is achieved by using a search engine. 37

38. UNIVERSITI TENAGA NASIONAL “Generates Professionals” Internet The Internet basics: –Users browse web pages by following hyperlinks. –Files, pictures, songs, and video can be shared downloading (receiving) and uploading (sending). –The Internet is also used for communicating with others through social networks, online games, forums, chat, e-mails, IM and VoIP. Voice over Internet Protocol (VoIP) is a technology that allows you to make voice calls using a broadband Internet connection instead of a regular (or analog) phone line. 38

39. UNIVERSITI TENAGA NASIONAL “Generates Professionals” 39 Text Book : Computers: Tools for an Information Age, 8 th Edition, H.L Capron, J.A Johnson Florida Center for Instructional Technology http://fcit.usf.edu/network/chap6/chap6.htm WebTechGeek.com www.webtechgeek.com/ How_to_Wi-Fi_Network.htm http://compnetworking.about.com http://www.computerhope.com/jargon/i/internet.htm References