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

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

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

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

Introduction to LANs Saad Haj Bakry Distance (meter) Data Rate (bps) Multi - Proce ssor Traditional LANs Traditional WANs High Speed WANs Metrop. Area Networks High- Speed LANs Network Classifications

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

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

IEEE I NSTITUTE OF E LECTRICAL & E LECTRONICS E NGINEERS A DDRESS: 345 East 47th Street, New York, NY 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

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

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): MHz / 2.4-2,4835 GHz / GHz / GHz I NFRATRD: Total Range ( ) Enhances security

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

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

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

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

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 Electronic & Telecommunications Industries Associations, USA ISO Similar to the above S TANDARDS: EIA/TIA Electronic & Telecommunications Industries Associations, USA ISO Similar to the above P RINCIPLES: Hierarchical / Star Layout

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

IEEE 802 : 3/8 Saad Haj Bakry Introduction to LANs Protocols DQDB: IEEE Distributed Queue “ Access Control ” Dual Bus “ Topology ” Designed for: Metropolitan Area Networks “ MANs ” DQDB: IEEE 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 (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 (But Higher Speed / Fiber) Designed for the Role of both LAN / MAN

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

Saad Haj Bakry Introduction to LANs SILS IEEE “ 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 “ Cable TV Based Broadband Comm. Network ” Multi- services Capabilities over CATV Systems: “ Data, Voice & Video / 2-Way / Remote Access & LAN Interconnection ”

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

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

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) 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 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.

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 ”

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 ”

Saad Haj Bakry Diffused Infrared Direct Beam Inf. Radio RATE (Mbps) 1-4 BAND MHz GHz GHz ACC. MTH. SEC. BEST CSMA SpSp: Freq. Hop. LAN / Characteristics nm GHZ (ISM) CSMA CSMA / Tok Rin CSMA / Res. ALOHA Introduction to LANs Topology W IRELESS LAN S SpSp: Dir. Seq. 10 MOD. LEAST

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.)

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

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

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 (%)

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

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)

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

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