Local Area Network (LAN) - Kasetsart University

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Local Area Network (LAN)

รศ.ดร.อนันต์ ผลเพิ่ม

Asso. Prof. Anan Phonphoem, [email protected]

http://www.cpe.ku.ac.th/~anan

Computer Engineering Department

Kasetsart University, Bangkok, Thailand

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Outline

Line Configuration

Topology

Multiple Access Protocol

LAN

Ethernet Address

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Line configuration

Defines the attachment of communication devices to a link

A link – A physical communication pathway

2 possible configurations

Point-to-point

Multipoint

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Point-to-point

Link between two devices

Use entire channel capacity for communication

Wire or wireless channel (link)

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Point-to-point

Satellite dish Satellite dish

Link

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Multipoint

More than 2 devices share a single link

Channel capacity is shared

Link

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Topology

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

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Mesh Topology

Each device has a dedicated point-to-point link

total links = n(n-1)/2

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Mesh Topology

Advantages High throughput

Robust

High Security

Easy to cope with fault

Disadvantages Number of cables – space & cost (material, install.)

Number of I/O ports

Difficult to reconfigure

Usage Backbone connecting

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Star Topology

Each device has a dedicated point-to-point link to a central controller (Hub)

ACTACT10M100M

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UPLINK

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PWR

SWITCH

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Tree Topology A variation of star

ACTACT10M100M

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UPLINK

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PWR

SWITCH

ACTACT10M100M

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UPLINK

1 2 3 4 5 6 7 8 9 101112

131415161718192021222324COLCOL

PWR

SWITCHACTACT

10M100M1 2 3 4

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UPLINK

1 2 3 4 5 6 7 8 9 101112

131415161718192021222324COLCOL

PWR

SWITCH

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Bus Topology

Each node connects to the Bus (a long cable running as a backbone)

Terminator

Bus Topology

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http://www.windowsnetworking.com/j_helmig/thin.htm

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Bus Topology

Advantages

Easy to install

Less cable compare to other topologies

Disadvantages

Difficult to cope with fault

Difficult to modify

Not robust

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Ring Topology

Each device has a dedicated point-to-point with its neighbors

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Ring Topology

Advantages

Easy to install

Easy to cope with fault

Disadvantages

Not robust

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Hybrid Topologies

ACTACT10M100M

1 2 3 4

13 14 15 16

5 6 7 8

17 18 19 20

9 10 11 12

21 22 23 24

UPLINK

1 2 3 4 5 6 7 8 9 101112

131415161718192021222324COLCOL

PWR

SWITCH

ACTACT10M100M

1 2 3 4

13 14 15 16

5 6 7 8

17 18 19 20

9 10 11 12

21 22 23 24

UPLINK

1 2 3 4 5 6 7 8 9 101112

131415161718192021222324COLCOL

PWR

SWITCH

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Multiple Access Protocol

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Random Access Evolution

MAMultiple access

CSMACarrier sense

Multiple access

CSMA/CDCarrier sense

Multiple accessCollision detect

CSMA/CACarrier sense

Multiple accessCollision avoidance

Transmission on a shared bus

20http://cnp3book.info.ucl.ac.be/1st/html/lan/lan.html

Collision on a shared bus

21http://cnp3book.info.ucl.ac.be/1st/html/lan/lan.html

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Collision in CSMA

Collision in CSMA

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

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CSMA/CD

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CSMA/CD animation

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CSMA/CD

CRS

collision

CRS

CRS

CRS

defer

defer

X

Y

Z

Modified from Lucent Slide

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CSMA/CA

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CSMA/CA

defer

CRS

CRS

defer

defer

CRS CRS

defer

X

Y

Z

Modified from Lucent Slide

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Token passing

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Token passing procedure

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Token Ring animation

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Ethernet

For Baseband:

Manchester Encoding

For Broadband (not popular):

Differential PSK (10Broad36)

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Notation

Thicknet

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10BASE5

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Notation

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10Base2

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Notation

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10BaseT

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100Base-TX

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1000Base-X

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Token Ring

Differential Manchester encoding

Support up to 16 Mbps

3 types of frames:

Data/command

Token

Abort

“Logical” Ring Topology

42https://www.microsoft.com/mspress/books/sampchap/5202/0735613788-07.gif

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MAU

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Token Ring Switch

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FDDI Rings

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FDDI Ring Failure

FDDI

47http://flylib.com/books/2/59/1/html/2/images/1587050900/graphics/05fig08.gif

Ethernet Address

Each device has a network interface card (NIC)

Can be called

MAC Address / Physical Address / Ethernet Address

Each NIC has a 6-byte address

Written in Hexadecimal notation

00-E0-00-AB-04-50

Ethernet Address

Unicast Address

(for source and Destination)

00-E0-00-AB-04-50

Broadcast Address FF-FF-FF-FF-FF-FF

Multicast Address 11-C0-02-D9-12-77

Find your NIC’s Vendor

Open terminal and find your MAC Address

Visit https://macvendors.com

Enter your mac address vendor

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00-E0-00-AB-04-50

OUI: Organizational Unique Identifier

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Summary

Line Configuration

Topology

Multiple Access Protocol

LAN

Ethernet

Token Ring / FDDI

Ethernet Address