2. WELCOME TO THE WORLD OF NETWORK CLICKTECHSOLUTION.COM

3. What is a network? A network is a group of computers / electronic devices that are able to communicate with one another and also share data, files, programs, and operations.

4. CLICKTECHSOLUTION.COM Why Network ??? ?Minimise Duplication ?Of Resources ?Of Applications/Programs ?Of Efforts ?Of Data ?Make Info/Resource Access Easy ?Improve Efficiency & Productivity ?Minimise Errors and Delays

5. CLICKTECHSOLUTION.COM Design Considerations Application Requirement Present Needs Future Needs

6. CLICKTECHSOLUTION.COM ?Network Architecture, ?Network Management & ?Network Security Key Issues

7. CLICKTECHSOLUTION.COM Network at Various Levels ?Local Area Networks ?Campus Networks ?Wide Area Networks ?Intranets ?Extranets ?Internet

8. CLICKTECHSOLUTION.COM LOCAL AREA NETWORK

9. CLICKTECHSOLUTION.COM LAN Involves Two or more computers connected together Communication and sharing Hardware and software Two or more computers connected together Communication and sharing Hardware and software

10. CLICKTECHSOLUTION.COM Local Area Network (LAN) ?Topology ?Cabling Systems ?Active Electronics

11. CLICKTECHSOLUTION.COM Topology ?Bus ?Star ?Ring ?Mesh

12. CLICKTECHSOLUTION.COM Bus Topology

13. CLICKTECHSOLUTION.COM Bus Topology Network maintained by a single cable Cable segment must end with a terminator Extra stations can be added in a daisy chain manner Standard is IEEE 802.3 Thin Ethernet (10Base2) has a maximum segment length of 200m Max no. of connections is 30 devices Four repeaters may be used to a total cable length of 1000m Network maintained by a single cable Cable segment must end with a terminator Extra stations can be added in a daisy chain manner Standard is IEEE 802.3 Thin Ethernet (10Base2) has a maximum segment length of 200m Max no. of connections is 30 devices Four repeaters may be used to a total cable length of 1000m

14. CLICKTECHSOLUTION.COM Thick Ethernet (10Base5) used for backbones, Limited to 500m Max of 100 nodes per segment Total of four repeaters, 2500m, with a total of 488 nodes Thick Ethernet (10Base5) used for backbones, Limited to 500m Max of 100 nodes per segment Total of four repeaters, 2500m, with a total of 488 nodes

15. CLICKTECHSOLUTION.COM Advantages Inexpensive to install Easy to add stations Use less cable than other topologies Works well for small networks Advantages Inexpensive to install Easy to add stations Use less cable than other topologies Works well for small networks Disadvantages No longer recommended Backbone breaks, whole network down Limited no of devices can be attached Difficult to isolate problems Sharing same cable slows response rates Disadvantages No longer recommended Backbone breaks, whole network down Limited no of devices can be attached Difficult to isolate problems Sharing same cable slows response rates

16. CLICKTECHSOLUTION.COM Star Topology Like the spokes of a wheel (without the symmetry) Centre point is a Hub Segments meet at the Hub Each device needs its own cable to the Hub Easy to maintain and expand Like the spokes of a wheel (without the symmetry) Centre point is a Hub Segments meet at the Hub Each device needs its own cable to the Hub Easy to maintain and expand

17. CLICKTECHSOLUTION.COM Advantages Easy to add devices as the network expands One cable failure does not bring down the entire network (resilience) Hub provides centralised management Easy to find device and cable problems Can be upgraded to faster speeds Lots of support as it is the most used Advantages Easy to add devices as the network expands One cable failure does not bring down the entire network (resilience) Hub provides centralised management Easy to find device and cable problems Can be upgraded to faster speeds Lots of support as it is the most used Disadvantages A star network requires more cable than a ring or bus network Failure of the central hub can bring down the entire network Costs are higher (installation and equipment) than for most bus networks Disadvantages A star network requires more cable than a ring or bus network Failure of the central hub can bring down the entire network Costs are higher (installation and equipment) than for most bus networks

18. CLICKTECHSOLUTION.COM Star Topology

19. CLICKTECHSOLUTION.COM TREE TOPOLOGY

20. CLICKTECHSOLUTION.COM Tree A tree topology combines characteristics of bus and star topologies. It consists of groups of star- configured workstations connected to a linear bus backbone cable (See fig.). Tree topologies allow for the expansion of an existing network, and enable schools to configure a meet their needs. network to Advantages of a Tree Topology Point-to-point wiring for individual segments. Supported by several hardware and software vend

21. CLICKTECHSOLUTION.COM Disadvantages of a Tree Topology Overall length of each segment is limited by the type of cabling used. If the backbone line breaks, the entire segment goes down. More difficult to configure and wire than other topologies.

22. CLICKTECHSOLUTION.COM Ring Topology No beginning or end (a ring in fact !!) All devices of equality of access to media Single ring – data travels in one direction only Each device has to wait its turn to transmit Most common type is Token Ring (IEEE 802.5) A token contains the data, reaches the destination, data extracted, acknowledgement of receipt sent back to transmitting device, No beginning or end (a ring in fact !!) All devices of equality of access to media Single ring – data travels in one direction only Each device has to wait its turn to transmit Most common type is Token Ring (IEEE 802.5) A token contains the data, reaches the destination, data extracted, acknowledgement of receipt sent back to transmitting device,

23. CLICKTECHSOLUTION.COM Ring Topology

24. CLICKTECHSOLUTION.COM Ring Topology Advantages Data packets travel at great speed No collisions Easier to fault find No terminators required Advantages Data packets travel at great speed No collisions Easier to fault find No terminators required Disadvantages Requires more cable than a bus A break in the ring will bring it down Not as common as the bus Disadvantages Requires more cable than a bus A break in the ring will bring it down Not as common as the bus

25. CLICKTECHSOLUTION.COM Mesh Topology

26. CLICKTECHSOLUTION.COM Mesh Topology Not common on LANs Most often used in WANs to interconnect LANS Each node is connected to every other node Allows communication to continue in the event of a break in any one connection It is “Fault Tolerant” Not common on LANs Most often used in WANs to interconnect LANS Each node is connected to every other node Allows communication to continue in the event of a break in any one connection It is “Fault Tolerant”

27. CLICKTECHSOLUTION.COM Mesh Topology Advantages Improves Fault Tolerance Advantages Improves Fault Tolerance Disadvantages Expensive Difficult to install Difficult to manage Difficult to troubleshoot Disadvantages Expensive Difficult to install Difficult to manage Difficult to troubleshoot

28. CLICKTECHSOLUTION.COM

29. BUS STAR HYBRID TOPOLOGIESTOPOLOGIES CLICKTECHSOLUTION.COM

30. Network in a building 1St Floor Switch Node Switch Node Switch Node 2nd Floor 3rd Floor SERVERS

31. CLICKTECHSOLUTION.COM Cabling Systems ?RS 232 ?10 Base 2 ?10 Base 5 ?10 Base T (UTP) ?100 Base T (UTP) ?Fiber Optic ?Use of Structured Cabling (upgrade,phased,error dect.)

32. CLICKTECHSOLUTION.COM Active Electronics ?NICs ?HUBs ?Switches ?Modems ?Routers

33. CLICKTECHSOLUTION.COM Key Issues in Selection of Electronics Present Application Requirements Provision for incorporating Future Technologies Cost Consideration Bandwidth Capacity Ease of Installation Ease of fault finding and maintenance

34. CLICKTECHSOLUTION.COM Campus Networks ? Topology ? Cabling ? Active Electronics ? Topology ? Cabling ? Active Electronics

35. CLICKTECHSOLUTION.COM (Topology) Campus Networks ?Bus ?Star ?Mesh ?Bus ?Star ?Mesh

36. CLICKTECHSOLUTION.COM Cabling (Campus Networks) ?Copper ?Fiber ?Wireless LAN

37. CLICKTECHSOLUTION.COM Campus Network Fiber Cable Block 1 Block 2 Central Block

38. CLICKTECHSOLUTION.COM Active Electronics (Campus Networks) ?Hubs ?Switches ?Short Range Modems

39. CLICKTECHSOLUTION.COM Wide Area Networks ?PSTN Based Networks ?Leased Line Based Networks ?VSAT Based Networks ?Other Related Network Methods based on Media like - Microwave, Radio Etc.,...

40. CLICKTECHSOLUTION.COM Remote Office Wide Area Network (PSTN Based) Remote Office PSTN Exchange Modem

41. CLICKTECHSOLUTION.COM Remote Office Wide Area Network (Leased line) Central Office Leased Line Modem Leased Line Modem LEASED LINE

42. CLICKTECHSOLUTION.COM Remote Office Satellite Wide Area Network (VSAT Based) Central Office VSAT

43. CLICKTECHSOLUTION.COM Major Intra-networking Components CABLE Hubs/Concentrator Network Interface Card File/LAN Server CABLE Hubs/Concentrator Network Interface Card File/LAN Server Physical connection between workstation Rebroadcast the digital signals to all workstation on LAN LAN communications port for each workstation Hosts Internal Network services for your organisation Physical connection between workstation Rebroadcast the digital signals to all workstation on LAN LAN communications port for each workstation Hosts Internal Network services for your organisation

44. CLICKTECHSOLUTION.COM Network Operating Systems NetWare Windows NT Server Unix (Unix variants) VMS (virtual machine sys) NetWare Windows NT Server Unix (Unix variants) VMS (virtual machine sys)

45. CLICKTECHSOLUTION.COM Networks can be Interoperable

46. CLICKTECHSOLUTION.COM Security Considerations: Identify and Authenticate Users Control Access to Systems Classify Data Encrypt Sensitive Data Audit and Monitor Activity Identify and Authenticate Users Control Access to Systems Classify Data Encrypt Sensitive Data Audit and Monitor Activity

47. CLICKTECHSOLUTION.COM Do’s & Don’ts in a Network Login & Logout properly Regular Back-up of Data Share Resources only to required Users Protect Resources by Passwords Protect Network from Virus Login & Logout properly Regular Back-up of Data Share Resources only to required Users Protect Resources by Passwords Protect Network from Virus Do not allow unauthorised Access Do not leave the systems in “LOGGED IN” state Do not use systems for other than required usage Do not tamper with the Network Do not allow unauthorised Access Do not leave the systems in “LOGGED IN” state Do not use systems for other than required usage Do not tamper with the Network

48. CLICKTECHSOLUTION.COM COMPARISON Wired Example Range Bandwidth (Mbps) LAN Ethernet 1-2 km 10-1000 WAN IP routing worldwide 0.010-600 MAN ATM 250 km 1-150 Internetwork Internet worldwide 0.5-600 Wireless: WPAN Bluetooth(802.15.1) 10 - 30m 0.5-2 WLAN WiFi(IEEE 802.11) 0.15-1.5 km 2-54 WMAN WiMAX(802.16) 550 km 1.5-20 WWAN GSM,3G phone nets worldwide 0.01-02 Wired Example Range Bandwidth (Mbps) LAN Ethernet 1-2 km 10-1000 WAN IP routing worldwide 0.010-600 MAN ATM 250 km 1-150 Internetwork Internet worldwide 0.5-600 Wireless: WPAN Bluetooth(802.15.1) 10 - 30m 0.5-2 WLAN WiFi(IEEE 802.11) 0.15-1.5 km 2-54 WMAN WiMAX(802.16) 550 km 1.5-20 WWAN GSM,3G phone nets worldwide 0.01-02

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