1. I NTRODUCTION TO L OCAL A REA N ETWORKS Professor Saad Haj Bakry, PhD, CEng, FIEE N ETWORK A RCHITECTURE

2. C ONTENTS Saad Haj Bakry B ASIC I SSUES LAN T OPOLOGY R EFERENCES LAN P ROTOCOLS LAN P ERFORMANCE Introduction to LANs S UGGESTED W ORK

3. B ASIC I SSUES Saad Haj Bakry LAN O BJECTIVES N ETWORK C LASSIFICATIONS Introduction to LANs N ETWORK S TRUCTURE S TANDARDS O RGANIZATIONS

4. LAN O BJECTIVES Saad Haj Bakry S HARING: Information / HW / SW Introduction to LANs E NABLED: by Microprocessors.. A PPLICATIONS: Data & Image Processing / Speech Recognition / Video Conferencing / Multimedia / Scope: “ Intranet ” with “ Extranet ” & “ Internet ” Extension Basic Issues

5. Introduction to LANs Saad Haj Bakry 10 8 10 7 10 6 10 5 10 4 10 -1 10 0 10 1 10 2 10 3 10 4 10 5 10 6 Distance (meter) Data Rate (bps) Multi - Proce ssor Traditional LANs Traditional WANs High Speed WANs Metrop. Area Networks High- Speed LANs Network Classifications

6. N ETWORK S TRUCTURE Saad Haj Bakry Introduction to LANs S S C OMMUNICATIONS S UBNETWORK: LAN Medium / Topology / Protocols / Interfacing S S S S S S S S S S S S S S S: A CCESS S TATION A CCESS S UBNETWORK Basic Issues

7. ISO I NTERNATIONAL S TANDARDS O RGANIZATION A DDRESS: PO Box 56, 1211 Geneva 20, Switzerland S TARTED: 1946 200 (TCs) Technical Committees 5000 (Standards) S TARTED: 1946 200 (TCs) Technical Committees 5000 (Standards) M EMBERS: 89 Countries ANSI: USA BSI: UK SASO: Saudi Arabia Saad Haj Bakry Introduction to LANs Basic Issues

8. IEEE I NSTITUTE OF E LECTRICAL & E LECTRONICS E NGINEERS A DDRESS: 345 East 47th Street, New York, NY 10017-2394 S TARTED: 1963 A Merger of the American Institute of Electrical Engineers (Started in 1884) and The Institute of Radio Engineers M EMBERS: Translational Individual Member Society Saad Haj Bakry Introduction to LANs A ROUND: 10 Divisions 40 Societies 300 Journals 500 (k) Members Groups for Standards: LAN IEEE 802 the basis for ISO 8802 A ROUND: 10 Divisions 40 Societies 300 Journals 500 (k) Members Groups for Standards: LAN IEEE 802 the basis for ISO 8802 Basic Issues

9. LAN T OPOLOGY Saad Haj Bakry T RANSMISSION M EDIUM Introduction to LANs B USS / T REE / R ING / S TAR S TRUCTURED C ABLING B ASEBAND B ROADBAND T OPOLOGY / M EDIUM I SSUES

10. T RANSMISSION M EDIUM T WISTED P AIR: Unshielded / Shielded Topology Saad Haj Bakry Introduction to LANs C OAXIAL C ABLE: Baseband / Broadband O PTICAL F IBER: Single Mode / Graded- index / Step-index U NGUIDED M EDIA M ICROWAVE (in Use): 902-928 MHz / 2.4-2,4835 GHz / 5.725-5.825 GHz / 18.825-19.205 GHz I NFRATRD: Total Range (10 12 -10 14 ) Enhances security

11. B USS T OPOLOGY Saad Haj Bakry Introduction to LANs T T T T T T T T T: Tap “ Hardware Interface ” R R R R R: “ Terminating Resistance ” T T Data Flow S S S S S S S S S S Transmitting / Receiving Stations Topology

12. T REE T OPOLOGY Saad Haj Bakry Introduction to LANs R R R R R R T T S S T T S S T T S S T T S S T T S S T T T T T T S S S S S S H H H: Head End Topology

13. R ING T OPOLOGY Saad Haj Bakry Introduction to LANs S S S S RPRP RPRP RPRP RPRP S S S S RPRP RPRP RPRP RPRP RP: Repeater Data Flow Topology

14. S TAR T OPOLOGY Saad Haj Bakry Introduction to LANs S S S S S S C ENTRAL H UB / S WITCH / R EPEATER S S S S S S S S S S Topology

15. S TRUCTURED C ABLING: 1/3 Saad Haj Bakry Introduction to LANs Topology O BJECTIVE: Generic cabling layout. Supports all types of information networking in buildings. Enables flexible movement of equipment (no rewiring / only plugging) O BJECTIVE: Generic cabling layout. Supports all types of information networking in buildings. Enables flexible movement of equipment (no rewiring / only plugging) S TANDARDS: EIA/TIA-668 2 Electronic & Telecommunications Industries Associations, USA ISO 11 801 Similar to the above S TANDARDS: EIA/TIA-668 2 Electronic & Telecommunications Industries Associations, USA ISO 11 801 Similar to the above P RINCIPLES: Hierarchical / Star Layout

16. S TRUCTURED C ABLING: 2/3 Saad Haj Bakry Introduction to LANs Topology H ORIZONTAL C ABLING : Single floor cabling. Backbone to wall outlets. Maximum distance: 90 (m). Fore more: multiple HC. B ACKBONE “ V ERTICAL ” C ABLING: Between floors L EVELS / C ONNECT: W: Work Area T: Telecom. Outlet TC: Telecom Closet ER: Equipment Room X: Cross Connect HC: Horizontal Connect IC: Intermediate Connect MC: Main Cross Connect TR: Termination L EVELS / C ONNECT: W: Work Area T: Telecom. Outlet TC: Telecom Closet ER: Equipment Room X: Cross Connect HC: Horizontal Connect IC: Intermediate Connect MC: Main Cross Connect TR: Termination

17. S TRUCTURED C ABLING: 3/3 Saad Haj Bakry Introduction to LANs Topology ER / MC TR ER / IC X X TR TCTC TCTC X X T T W: Work Area Outlets TCTC TCTC T T X X TR W: Work Area Outlets H ORIZONTAL C ABLING B ACKBONE “ V ERTICAL ” C ABLING

18. T RANSMISSION T ECHNIQUES: B ASEBAND S IGNALING: Digital: No Carrier / No FDM Entire bandwidth is given to a signal Bidirectional S IGNALING: Digital: No Carrier / No FDM Entire bandwidth is given to a signal Bidirectional B USS T OPOLOGY Saad Haj Bakry Introduction to LANs D ISTANCE: Up to a “ few kms ” Topology

19. T RANSMISSION T ECHNIQUES: B ROADBAND S IGNALING: Analog: RF Modem / FDM possible Multiple Data Channels / Audio / Video Unidirectional S IGNALING: Analog: RF Modem / FDM possible Multiple Data Channels / Audio / Video Unidirectional B USS / T REE T OPOLOGY Saad Haj Bakry Introduction to LANs D ISTANCE: Up to a “ 10s of kms ” Topology

20. B ROADBAND B USS Saad Haj Bakry Introduction to LANs Receive on “ f2 ” Transmit on “ f1 ” S S S S S S “ f2 ” “ f1 ” Single Buss S S S S S S Dual Buss Transmit on “ f1 ” Receive on “ f1 ” Topology

21. LAN T OPOLOGY / M EDIUM Saad Haj Bakry Twisted Pair Coax. Cable: Baseband Optical Fiber Wireless RING Y Y BUSS Y TREESTAR Y Y N Y Y Y Y Y Y Coax. Cable: Broadband M EDIUM / T OPOLOGY Y Y N N N N N N Introduction to LANs Topology

22. B USS / T REE T OPOLOGY Saad Haj Bakry Unshielded Twisted Pair Optical Fiber Wireless RATE (Mbps) 50 RANG E(km) TAPS 10s 10-50 45 <30 500 Coax. Cable: Baseband M EDIUM / S PECIFICATION 1 10 <2 <3 <150 <1 100s- 1000s 100s Coax. Cable: Broadband Introduction to LANs Topology

23. R ING T OPOLOGY Saad Haj Bakry Unshielded Twisted Pair Optical Fiber Wireless RATE (Mbps) 16 R P. S P. (m) TAPS 10s 70 16 100 1000 250 Coax. Cable: Baseband M EDIUM / S PECIFICATION 4 100 300 2000 100 250 Shielded Twisted Pair Introduction to LANs Topology

24. S TAR T OPOLOGY Saad Haj Bakry Optical Fiber Wireless 10s 100 10s 10 100 <1000 Unshielded Twisted Pair RATE (Mbps) S-H Distance (m) Stations 10s 100 M EDIUM / S PECIFICATION 10-100 100 10s Shielded Twisted Pair Introduction to LANs Topology

25. LAN P ROTOCOLS Saad Haj Bakry ISO / OSI Introduction to LANs LAN L AYERS IEEE 802 S TANDARDS CSMA / CD T OKEN B US / R ING W IRELESS LAN ATM LAN

26. ISO- OSI T RANSPORT D ATA L INK P HYSICAL N ETWORK S ESSION P RESENTATION A PPLICATION O PEN S YSTEM I NTERCONNECTION: R EFERENCE M ODEL S TARTED: 1983 Protocols Saad Haj Bakry Introduction to LANs

27. ISO-OSI L AYERS A PPLICATION P RESENTATION S ESSION T RANSPORT` N ETWORK D ATA L INK P HYSICAL A PPLICATION P RESENTATION S ESSION T RANSPORT` N ETWORK D ATA L INK P HYSICAL COMMUNICATI ON MEDIUM P HYSICAL D ATA L INK N ETWORK COMMUNICATION SUBNETWORK COMMUNICATI ON MEDIUM P EER L EVELS Protocols Saad Haj Bakry Introduction to LANs

28. ISO-OSI F UNCTIONS A PPLICATION: Supporting Services at Access Points P RESENTATION: Representation of Information S ESSION: User Interface to the Network T RANSPORT: End to End QOS N ETWORK: Sub-network Operation D ATA L INK: Point to Point Error Free P HYSICAL: Interface to the Medium I NTERNETWORKING I NTERCONNECTION Protocols Saad Haj Bakry Introduction to LANs

29. R EPEATERS / B RIDGES / R OUTERS / G ATEWAYS A PPLICATION P RESENTATION S ESSION T RANSPORT` N ETWORK D ATA L INK P HYSICAL A PPLICATION P RESENTATION S ESSION T RANSPORT` N ETWORK D ATA L INK P HYSICAL COMMUNICATI ON MEDIUM Protocols Saad Haj Bakry Introduction to LANs G ATEWAY R OUTER B RIDGE R EPEATER G ATEWAY R OUTER B RIDGE R EPEATER

30. U SING ISO-OSI A PPLICATION P RESENTATION S ESSION T RANSPORT` N ETWORK D ATA L INK P HYSICAL A PPLICATION P RESENTATION S ESSION T RANSPORT` N ETWORK D ATA L INK P HYSICAL COMMUNICATION MEDIUM DATA APSTNLH A A A A A A P P P P P S S S S T T T N NL Protocols Saad Haj Bakry Introduction to LANs

31. Protocols L AYERED P ROTOCOLS Saad Haj Bakry Introduction to LANs P HYSICAL L AYER: Electrical & Mechanical “ Characteristics ” of “ Interconnections ” / Related to the Communication “ Medium ” to be Used M EDIUM A CCESS C ONTROL (SubLayer): Converts the “ Shared ” physical link into “ Virtual ” point-to-point links between pairs of computers L OGICAL L INK C ONTROL (SubLayer): Supervises “ Transmission ” between Nodes / Related to “ Higher ” Layers D ATA L INK L AYER LLC + MAC

32. IEEE 802 : 1/8 Saad Haj Bakry Introduction to LANs HILI: IEEE 802.1 “ Higher Level Interface ” Concerned with LAN Architecture, Internetworking, & Management Protocols LLC: IEEE 802.2 “ Logical Link Control ” CSMA/CD “ MAC Ethernet ” : IEEE 802.3 “ Carrier Sense Multiple Access / Collision Detection ” Originally Designed for: Commercial / Light Industrial Environment (Random Use / Simple) CSMA/CD “ MAC Ethernet ” : IEEE 802.3 “ Carrier Sense Multiple Access / Collision Detection ” Originally Designed for: Commercial / Light Industrial Environment (Random Use / Simple)

33. IEEE 802 : 2/8 Saad Haj Bakry Introduction to LANs Protocols T OKEN B US “ MAC ” : IEEE 802.4 Originally Designed for: Office Environment / Factories & Industrial Environment / Military Environment T OKEN B US “ MAC ” : IEEE 802.4 Originally Designed for: Office Environment / Factories & Industrial Environment / Military Environment T OKEN R ING “ MAC ” : IEEE 802.5 Originally Designed for: Commercial / Light Industrial Environment (Like Ethernet: 802.3) T OKEN R ING “ MAC ” : IEEE 802.5 Originally Designed for: Commercial / Light Industrial Environment (Like Ethernet: 802.3)

34. IEEE 802 : 3/8 Saad Haj Bakry Introduction to LANs Protocols DQDB: IEEE 802.4 Distributed Queue “ Access Control ” Dual Bus “ Topology ” Designed for: Metropolitan Area Networks “ MANs ” DQDB: IEEE 802.4 Distributed Queue “ Access Control ” Dual Bus “ Topology ” Designed for: Metropolitan Area Networks “ MANs ” FDDI “ Fiber Distributed Data Interface ” : ANSI X3T9.5 / ISO 9314 / T OKEN R ING: IEEE 802.5 (But Higher Speed / Fiber) Designed for the Role of both LAN / MAN FDDI “ Fiber Distributed Data Interface ” : ANSI X3T9.5 / ISO 9314 / T OKEN R ING: IEEE 802.5 (But Higher Speed / Fiber) Designed for the Role of both LAN / MAN

35. Saad Haj Bakry Introduction to LANs BBTAG IEEE 802.7 “ Broadband Technical Advisory Group ” Produced a Document on “ Broadband Cabling Systems ” ISLAN: IEEE 802.9 “ Integrated Services LAN Interface ” (Desktop Devices “ to ” 802 LANs & ISDN) Protocols IEEE 802 : 4/8 FOTAG IEEE 802.8 “ Fibre Optics Technical Advisory Group ” Using Optical Fiber for: IEEE 802.3/4/5 FOTAG IEEE 802.8 “ Fibre Optics Technical Advisory Group ” Using Optical Fiber for: IEEE 802.3/4/5

36. Saad Haj Bakry Introduction to LANs SILS IEEE 802.10 “ Standard for Interoperable LAN Security ” Functions: “ Secure Data Exchange / Security & Encryption Key Management / Application of OSI Security ” Protocols IEEE 802 : 5/8 CATVB-BCN IEEE 802.14 “ Cable TV Based Broadband Comm. Network ” Multi- services Capabilities over CATV Systems: “ Data, Voice & Video / 2-Way / Remote Access & LAN Interconnection ”

37. Saad Haj Bakry Introduction to LANs WLAN IEEE 802.11 “ Wireless LAN ” Saves Cabling / Provides: LAN Extensions, Cross-Building Interconnection, Nomadic Access,.. WLAN IEEE 802.11 “ Wireless LAN ” Saves Cabling / Provides: LAN Extensions, Cross-Building Interconnection, Nomadic Access,.. Protocols IEEE 802 : 6/8 Demand Priority IEEE 802.12 “ Priority Order is Assigned to the Nodes Sharing the Network ” Used with Higher Speed: 100 Mbps: 100VG-ANYLAN Demand Priority IEEE 802.12 “ Priority Order is Assigned to the Nodes Sharing the Network ” Used with Higher Speed: 100 Mbps: 100VG-ANYLAN

38. IEEE 802 : 7/8 Saad Haj Bakry Introduction to LANs PLPL PLPL MACMAC MACMAC IEEE 802.2 LLC IEEE 802.3 CSMA / CD IEEE 802.3 CSMA / CD IEEE 802.4 Token Bus IEEE 802.4 Token Bus IEEE 802.12 Demand Priority IEEE 802.12 Demand Priority Bus / Tree / Star Topology IEEE 802.5 Token Ring Ring Topology IEEE 802.6 DQDB: Distr. Queue Dual Bus IEEE 802.6 DQDB: Distr. Queue Dual Bus FDDI Token Ring FDDI Token Ring Dual Bus Topology Protocols

39. IEEE 802 : 8/8 Saad Haj Bakry Introduction to LANs Protocols LLC B ASIC F UNCTIONS: Frame Multiplexing Error Control Flow Control (if required) LLC B ASIC F UNCTIONS: Frame Multiplexing Error Control Flow Control (if required) 802.2 LLC S ERVICES T YPES: Connection Oriented Service: packet streams are delivered in their correct order without error. Connectionless Service: Data gram transmission. Correct order is not guaranteed Acknowledged Connectionless: For point to point connections. No frame is sent before the previous one is acknowledged. 802.2 LLC S ERVICES T YPES: Connection Oriented Service: packet streams are delivered in their correct order without error. Connectionless Service: Data gram transmission. Correct order is not guaranteed Acknowledged Connectionless: For point to point connections. No frame is sent before the previous one is acknowledged.

40. E THERNET CSMA / CD Saad Haj Bakry Introduction to LANs ALOHA / S LOTTED ALOHA: A station transmits whenever it has data to send. Un acknowledged transmissions are repeated. With “ slotted ALOHA ” data packets are transmitted in well defined time slots. “ Collision / interference ” is resolved by retransmission after random intervals. ALOHA / S LOTTED ALOHA: A station transmits whenever it has data to send. Un acknowledged transmissions are repeated. With “ slotted ALOHA ” data packets are transmitted in well defined time slots. “ Collision / interference ” is resolved by retransmission after random intervals. Protocols CSMA: Stations sense the medium, and may send only if it is idle CSMA / CD: Transmission is ceased if a collision is detected These are “ contention techniques ”

41. T OKEN B US / R ING Saad Haj Bakry Introduction to LANs Protocols T OKEN B US: Stations on “ Bus / Tree ” form a logical ring around which a token is passed (played). A station receiving a token may transmit (insert data into token). Data (into token) travel from source to destination through the logical ring T OKEN B US: Stations on “ Bus / Tree ” form a logical ring around which a token is passed (played). A station receiving a token may transmit (insert data into token). Data (into token) travel from source to destination through the logical ring T OKEN R ING: Stations are connected to a “ Physical Ring ”, through which the “ token game ” is played T OKEN R ING: Stations are connected to a “ Physical Ring ”, through which the “ token game ” is played “ No Contention ”

42. Saad Haj Bakry Diffused Infrared Direct Beam Inf. Radio RATE (Mbps) 1-4 BAND 908-928 MHz 2.4-2.4835 GHz 5.725-5.85 GHz ACC. MTH. SEC. BEST 1-3 2-20 5-10 CSMA SpSp: Freq. Hop. LAN / Characteristics 800- 900 nm 18.825- 19.205 GHZ (ISM) CSMA CSMA / Tok Rin CSMA / Res. ALOHA Introduction to LANs Topology W IRELESS LAN S SpSp: Dir. Seq. 10 MOD. LEAST

43. ATM LAN: 1/2 Saad Haj Bakry Introduction to LANs Protocols AAL: ATM A DAPTATION L AYER The layer that maps information transfer protocols onto ATM ATM: A SYNCHRONOUS T RANSFER M ODE A form of packet switching using fixed size packets, called cells. It is a data transfer interface for BISDN. No error control and no flow control mechanisms P HYSICAL L AYER Related to BISDN channels (Optical Fiber): 155 & 622 Mbps and above. Also used on High Speed digital channels: 45 Mbps (sat.)

44. Protocols Saad Haj Bakry Introduction to LANs P HYSICAL MAC LLC P HYSICAL ATM A DAPTATION L OWER L AYERS IP TCP I NTERNET A PPLICATIONS H IGHER L AYERS ATM LAN: 1/2

45. B ASIC P ERFORMANCE M EASURES Saad Haj Bakry Introduction to LANs T HROUGHPUT L ATENCY

46. T HROUGHPUT Saad Haj Bakry Introduction to LANs D EFINITION: Average successful transmission rate when the LAN is heavily loaded E XAMPLES: CSMA / Ethernet: 65 % FDDI / Token Ring Close to 100 % E XAMPLES: CSMA / Ethernet: 65 % FDDI / Token Ring Close to 100 % Performance MAC E FFICIENCY: ( Throughput) / (Max. Rate) Can be given as (%)

47. Saad Haj Bakry Introduction to LANs D EFINITION: Latency is the time from packet generation (its arrival to network interface) until it reaches its destination C ONVERSATION A PPLICATIONS “ Voice / Data ” : Max. Value 100 (ms) L ATENCY Performance Conflict: Throughput Versus Latency

48. S UGGESTED W ORK Saad Haj Bakry Introduction to LANs E XTENSIONS: Theory: Different LANs Systems: Available LANs / Management Issues Components: LAN Architecture E XTENSIONS: Theory: Different LANs Systems: Available LANs / Management Issues Components: LAN Architecture P RACTICAL: Applications: LANs in Use (LAN Architecture / Users / Services) Measurements: Performance Monitoring P RACTICAL: Applications: LANs in Use (LAN Architecture / Users / Services) Measurements: Performance Monitoring A NALYSIS: Practical Evaluations: Criteria (Different LANs) Planning & Design Issues: Requirements (Case Studies) A NALYSIS: Practical Evaluations: Criteria (Different LANs) Planning & Design Issues: Requirements (Case Studies)

49. R EFERENCES: 1/2 Saad Haj Bakry Introduction to LANs A. S. Tanenbaum, Computer Networks, 3rd Ed., Prentice Hall, 1996 W. Stallings, Data and Computer Communications, 5th Ed., Prentice Hall, 1997 A. Macpherson, International Telecommunication Standards Organizations, Artech House, 1990 W. Stallings, Local & Metropolitan Area Networks, Prentice Hall, 1997

50. R EFERENCES: 2/2 Saad Haj Bakry Introduction to LANs R. P. Davidson, N. J. Muller, Internetworking LANs: Operation, Design & Management, Artech House, 1992 J. Walrand, Communication Network: A First Course, 2nd Ed., McGraw-Hill, 1998