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REMOTE ACCESS Lecture II

REMOTE ACCESS Lecture II. REMOTE ACCESS. Presented By:- Dr. Fred Zellner University Of Houston Central Computing and Telecommunication Services. REMOTE ACCESS. What Is It ? Accessing a network from a remote location Accessing the LAN from a remote location Accessing the Internet.

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REMOTE ACCESS Lecture II

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  1. REMOTE ACCESSLecture II REMOTE ACCESS Presented By:- Dr. Fred Zellner University Of Houston Central Computing and Telecommunication Services Datacom II REMOTE ACCESS

  2. REMOTE ACCESS What Is It ? Accessing a network from a remote location • Accessing the LAN from a remote location • Accessing the Internet Datacom II REMOTE ACCESS

  3. REMOTE ACCESS WHY REMOTE ACCESS ? • E-Mail and File Transfers • Online transaction processing • Emphasis on telecommuting • Price reductions in portable systems • Competitive Pressures Datacom II REMOTE ACCESS

  4. REMOTE ACCESS TYPES OF REMOTE ACCESS Datacom II REMOTE ACCESS

  5. REMOTE ACCESS REMOTE ACCESS USERS HOME OFFICE REMOTE ACCESS SOHO TRAVELLING EMPLOYEE OUTBOUND Datacom II REMOTE ACCESS

  6. REMOTE ACCESS FUTURE ARCHITECTURE Data Management SERVER Application Logic Remote Middleware SATELLITE WIRELESS WAN ISDN ADSL MODEM CABLE MODEM Remote Middleware Data Management MOBILE/ REMOTE CLIENT Application Logic Presentation Source:-Gartner Group Datacom II REMOTE ACCESS

  7. REMOTE ACCESS FEATURES OF THE ARCHITECTURE • STORE AND FORWARD • SINGLE SESSION COMMUNICATIONS • NETWORK INDEPENDENCE Datacom II REMOTE ACCESS

  8. REMOTE ACCESS BANDWIDTH DEMAND FORECAST TOTAL DESIRED BANDWIDTH :- 528 Kbps Source:-Gartner Group Datacom II REMOTE ACCESS

  9. REMOTE ACCESS OPTIMIZATION TECHNIQUES • GENERIC TECHNIQUES • LAN BASED TRAFFIC OPTIMIZATION • APPLICATION DRIVEN TECHNIQUES Datacom II REMOTE ACCESS

  10. REMOTE ACCESS GROWTH IN NUMBER OF REMOTE ACCESS USERS No.of Users (in Millions) Source:Gartner Group Datacom II REMOTE ACCESS

  11. REMOTE ACCESS SUMMARY TILL NOW… • More than 32m remote users by 2000. • By 2001,Remote Access will be a necessity not a luxury. • Bandwidth requirement will shoot up. • By, 2001 new applications for Deferred Remote Access will be written. • By 2001, Remote Performance Optimization standards will come in place. Datacom II REMOTE ACCESS

  12. REMOTE ACCESS MODEM TECNOLOGY Datacom II REMOTE ACCESS

  13. REMOTE ACCESS DIAL UP MODEMS TILL NOW…. Older Standards V.32 V.32 bis V.34 V.34+ 33.6Kbps V.34+ 28.8Kbps V.34 14.4Kbps V.32bis 9600bps V.32 300bps Datacom II REMOTE ACCESS

  14. REMOTE ACCESS DIAL UP MODEMS WHAT NOW…. • Kflex 56.(Motorola) • X 2(3Com) 56 Kbps Kflex 56 X2 33.4 Kbps V.34 Datacom II REMOTE ACCESS

  15. REMOTE ACCESS THE 56K TECHNOLOGY Datacom II REMOTE ACCESS

  16. REMOTE ACCESS FEATURES OF THE 56K TECHNOLOGY • SERVICES OVER REGULAR PHONE LINES. • 100% DIGITAL NETWORK EXCEPT THE LOCAL LOOP. • DOWNLOADS FROM INTERNET,CORPORATE NETWORKS AT 56Kbps. • BACKWARD COMPATIBLE. Datacom II REMOTE ACCESS

  17. REMOTE ACCESS 100% DIGITAL CONNECTION EXCEPT THE LOCAL LOOP. ASYMMETRICAL CONNECTION. UPSTREAM SPEED LIMITED DUE TO A/D CONVERSION. USE “PAM” IN DOWNSTREAM AND “QAM” IN UPSTREAM. OPTIMIZED FOR END TO END ANALOG CONNECTIONS. SYMMETRICAL CONNECTION. A/D CONVERSION TAKING PLACE AT BOTH ENDS HENCE LIMITING SPEED. USES “QAM” IN BOTH DIRECTIONS. DIFFERENCE BETWEEN 56K AND V.34 TECHNOLOGY Datacom II REMOTE ACCESS

  18. REMOTE ACCESS 56K DIAL UP MODEM REQUIREMENTS • DIGITAL AT ONE END. • 56K TECHNOLOGY SUPPORT AT BOTH ENDS. • ONE ANALOG TO DIGITAL CONVERSION. Datacom II REMOTE ACCESS

  19. DEVELOPED BY ROCKWELL AND LUCENT. DEVELOPED BY US ROBOTICS AND 3COM. REMOTE ACCESS THE 56K MODEM TECHNOLOGY SUPPLIERS Datacom II REMOTE ACCESS

  20. REMOTE ACCESS DISADVANTAGES OF 56K MODEMS • USEFUL ONLY FOR INTERNET DOWNLOADS. • NO STANDARDIZATION FROM ITU-IT. • NO VIDEOCONFERENCING AND MULTIMEDIA APPLICATIONS POSSIBLE. Datacom II REMOTE ACCESS

  21. REMOTE ACCESS CABLE MODEMS Datacom II REMOTE ACCESS

  22. REMOTE ACCESS WHAT IS CABLE MODEM TECHNOLOGY ? • HIGH SPEED DATA TRANSFER VIA THE BROADBAND CABLE TV NETWORK. Datacom II REMOTE ACCESS

  23. REMOTE ACCESS TYPICAL SCENARIO….. COAXIAL CABLE TWISTED PAIR SERIAL CABLE Datacom II REMOTE ACCESS

  24. REMOTE ACCESS WITH CABLE MODEM TECHNOLOGY…. COAXIAL CABLE TWISTED PAIR CABLE MODEM Datacom II REMOTE ACCESS

  25. REMOTE ACCESS WHAT IS A CABLE MODEM ? • ACTS AS A BRIDGE, SPANNING THE CABLE MEDIA’S ACCESS PROTOCOL AND THE PC’S COMMUNICATION PROTOCOL. • OPERATES AT LAYER 1 AND LAYER 2. • HAS CONNECTORS FOR POWER,VIDEO F AND ETHERNET CONNECTOR. Datacom II REMOTE ACCESS

  26. REMOTE ACCESS CABLE TV PRIMER • COAXIAL CABLES:-330Mhz or 450MHz. • DOWNSTREAM VIDEO:-50Mhz-750Mhz. • UPSTREAM VIDEO:-5Mhz-42Mhz. • STANDARD TV CHANNEL OCCUPIES 6Mhz. • TRADITIONAL TV SYSTEM:-60 CHANNELS. Datacom II REMOTE ACCESS

  27. REMOTE ACCESS BANDWIDTH ALLOCATION …. DOWNSTREAM 750Mhz UPSTREAM 50Mhz 42Mhz 5Mhz Datacom II REMOTE ACCESS

  28. REMOTE ACCESS CABLE MODEM SPEEDS Datacom II REMOTE ACCESS

  29. REMOTE ACCESS CABLE MODEM SPEEDS Datacom II REMOTE ACCESS

  30. REMOTE ACCESS SERVICES PROVIDED BY CABLE MODEMS • INTERNET ACCESS • ELECTRONIC MAIL • REMOTE ACCESS TO CORPORATE LAN. Contd…. Datacom II REMOTE ACCESS

  31. REMOTE ACCESS SERVICES…… • INTEGRATED COMPUTER/TV ACCESS. • BANK AT HOME SERVICES. • HOME ENTERTAINMENT. Datacom II REMOTE ACCESS

  32. REMOTE ACCESS CABLE NETWORK Datacom II REMOTE ACCESS

  33. REMOTE ACCESS CABLE MODEM NETWORK:-AN EXAMPLE Datacom II REMOTE ACCESS

  34. REMOTE ACCESS EXPLANATION…. • SuperHeadend:-Heart of the System • LCp:-Personal Cable Modem • LCw:-Workgroup Cable Modem. • LCb:-Multiuser Cable Modem. Datacom II REMOTE ACCESS

  35. REMOTE ACCESS CABLE MODEMS:--AVERAGE COST Datacom II REMOTE ACCESS

  36. REMOTE ACCESS BANDWIDTH COST COMPARISON $/Kbps Datacom II REMOTE ACCESS

  37. REMOTE ACCESS 1. Time Warner Cable 29,000 2. MediaOne 17,000 14,000 3. Cox Communications 16,000 4. Rogers Cablesystems 14,000 5. Comcast 5,800 6. Videotron 5,000 7. Shaw Communications 4,500 8. COGECO 4,000 9. Tele-Communications Inc. 2,400 10. Adelphia 2,000 11. Cablevision Systems 1,400 12. Jones Intercable 4,000 Other 4,000 TOTAL 111,100 CABLE MODEM SALES Datacom II REMOTE ACCESS

  38. REMOTE ACCESS CABLE MODEM--SUBSCRIBER PROJECTIONS Datacom II REMOTE ACCESS

  39. REMOTE ACCESS CABLE MODEMS:--UNIT SALES PROJECTIONS Datacom II REMOTE ACCESS

  40. REMOTE ACCESS DISADVANTAGES OF CABLE MODEMS • HUGE INVESTMENT BY MSO. • RELIABLE MANAGEMENT SYSTEM REQUIRED. • NO INTEROPERABILITY BETWEEN DIFFERENT MODEMS. • UPSTREAM SPEEDS NOT STANDARDIZED. Datacom II REMOTE ACCESS

  41. REMOTE ACCESS PRESENT SCENARIO • NO STANDARDS. • PRESENT CUSTOMERS ARE MSO’s. • NO SUPPLIERS TO PROVIDE END TO END SOLUTIONS. Datacom II REMOTE ACCESS

  42. REMOTE ACCESS CABLE MODEMS--FUTURE • STANDARDIZATION FOR DOWNSTREAM AND UPSTREAM SPEEDS. • INTEROPERABILITY BETWEEN DIFFERENT MODEMS. • REDUCTION IN COSTS. • CUSTOMERS WILL BE END USERS. • SUPPLIERS WITH END TO END SOLUTIONS. Datacom II REMOTE ACCESS

  43. REMOTE ACCESS ASYNCHRONOUS DIGITAL SUSCRIBER LINE HIT THE HIGHWAY WITHOUT LEAVING HOME Datacom II REMOTE ACCESS

  44. REMOTE ACCESS WHAT IS ADSL ? • ASYNCHRONOUS DIGITAL SUBSCRIBER LINE--- A NEW MODEM TECHNOLOGY. Datacom II REMOTE ACCESS

  45. REMOTE ACCESS ADSL FEATURES • HIGH SPEED NETWORK ACCESSIBILITY. • HIGH SPEED REMOTE ACCESS. • VIDEO ON DEMAND. • CONSTANT CONNECTIVITY. • NO NEED TO ADD NEW PHONE LINES. Datacom II REMOTE ACCESS

  46. REMOTE ACCESS ADSL :- THE NETWORK Datacom II REMOTE ACCESS

  47. REMOTE ACCESS ADSL….SPEEDS • ADSL MODEMS CONSISTENT WITH EUROPEAN AND NORTH AMERICAN DIGITAL HIERARCHIES. • VARIABLE DATA RATES. Datacom II REMOTE ACCESS

  48. REMOTE ACCESS TECHNOLOGY DESCRIPTION…Requirements • FULL USE OF COPPER LINE FREQUENCY SPECTRUM(1.1Mhz). • ADVANCED CODING/DECODING METHOD. • ABILITY TO WORK WITH POTS ON SAME COPPER LINE. • AN EFFICIENT ERROR CORRECTION CODE. Datacom II REMOTE ACCESS

  49. REMOTE ACCESS TECHNOLOGIES USED BY ADSL • CODING:--DMT OR CAP • CODE AND ERROR CORRECTION • FRAMING AND SCRAMBLING Datacom II REMOTE ACCESS

  50. REMOTE ACCESS ADSL:--BANDWIDTH ALLOCATION Datacom II REMOTE ACCESS

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