Local Area Network LAN Asso Prof Anan Phonphoem

Local Area Network (LAN) รศ. ดร. อนนต ผลเพม Asso. Prof. Anan Phonphoem, Ph. D. anan. p@ku. ac. th http: //www. cpe. ku. ac. th/~anan Computer Engineering Department Kasetsart University, Bangkok, Thailand 1

Outline n n n Line Configuration Topology Multiple Access Protocol LAN Ethernet Address 2

Line configuration n Defines the attachment of communication devices to a link A link – A physical communication pathway 2 possible configurations n n Point-to-point Multipoint 3

Point-to-point n n n Link between two devices Use entire channel capacity for communication Wire or wireless channel (link) 4

Point-to-point Link 5

Multipoint n n More than 2 devices share a single link Channel capacity is shared Link 6

Topology n n The way a network is physically or logically layout 2 or more devices connected to a link 2 or more links form a topology Basic topologies • • • Mesh Star Tree • • • Bus Ring Hybrid 7

Mesh Topology n Each device has a dedicated point-to-point link total links = n(n-1)/2 8

Mesh Topology n Advantages n n n Disadvantages n n High throughput Robust High Security Easy to cope with fault Number of cables – space & cost (material, install. ) Number of I/O ports Difficult to reconfigure Usage n Backbone connecting 9

Star Topology n Each device has a dedicated point-to-point link to a central controller (Hub) 10

Tree Topology n A variation of star 11

Bus Topology n Each node connects to the Bus (a long cable running as a backbone) Terminator 12

Bus Topology http: //www. windowsnetworking. com/j_helmig/thin. htm 13

Bus Topology n Advantages n n n Easy to install Less cable compare to other topologies Disadvantages n n n Difficult to cope with fault Difficult to modify Not robust 14

Ring Topology n Each device has a dedicated point-to-point with its neighbors 15

Ring Topology n Advantages n n n Easy to install Easy to cope with fault Disadvantages n Not robust 16

Hybrid Topologies 17

Multiple Access Protocol 18

Random Access Evolution MA Multiple access CSMA Carrier sense Multiple access CSMA/CD Carrier sense Multiple access Collision detect CSMA/CA Carrier sense Multiple access Collision avoidance 19

Transmission on a shared bus http: //cnp 3 book. info. ucl. ac. be/1 st/html/lan. html 20

Collision on a shared bus http: //cnp 3 book. info. ucl. ac. be/1 st/html/lan. html 21

Collision in CSMA 22

Collision in CSMA http: //www. spectrose. com/what-is-ethernet-how-it-works. html 23

CSMA/CD 24

CSMA/CD animation 25

CSMA/CD X CRS defer Y CRS defer Z CRS collision Modified from Lucent Slide 26

CSMA/CA 27

CSMA/CA X Y CRS defer Z CRS defer CRS Modified from Lucent Slide 28

Token passing 29

Token passing procedure 30

Token Ring animation 31

Ethernet n For Baseband: n n Manchester Encoding For Broadband (not popular): n Differential PSK (10 Broad 36) 32

Notation Thicknet 33

10 BASE 5 34

Notation 35

10 Base 2 36

Notation 37

10 Base. T 38

100 Base-TX 39

1000 Base-X 40

Token Ring n n n Differential Manchester encoding Support up to 16 Mbps 3 types of frames: n n n Data/command Token Abort 41

“Logical” Ring Topology https: //www. microsoft. com/mspress/books/sampchap/5202/0735613788 -07. gif 42

MAU 43

Token Ring Switch 44

FDDI Rings 45

FDDI Ring Failure 46

FDDI http: //flylib. com/books/2/59/1/html/2/images/1587050900/graphics/05 fig 08. gif 47

Ethernet Address n n Each device has a network interface card (NIC) Can be called n n n MAC Address / Physical Address / Ethernet Address Each NIC has a 6 -byte address Written in Hexadecimal notation 00 -E 0 -00 -AB-04 -50

Ethernet Address Unicast Address 00 -E 0 -00 -AB-04 -50 (for source and Destination) Broadcast Address FF-FF-FF-FF Multicast Address 11 -C 0 -02 -D 9 -12 -77

Find your NIC’s Vendor n n n Open terminal and find your MAC Address Visit https: //macvendors. com Enter your mac address vendor OUI: Organizational Unique Identifier 00 -E 0 -00 -AB-04 -50 50

Summary n n Line Configuration Topology Multiple Access Protocol LAN n n n Ethernet Token Ring / FDDI Ethernet Address 51