DCCN Lecture 5 [Compatibility Mode]

8/16/2019 DCCN Lecture 5 [Compatibility Mode]

1/17

Data Communicationand Computer Networks

[EEE 314]

Mubashir Husain Rehmani

Assistant Professor

Department of Electrical Engineering

COMSATS Institute of Information Technology,

Wah Cantt, Pakistan


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Connecting Devices

Physical Layer Repeater or Hub

a a n ayer r ge or ayer wo w c

Network Layer Router or Layer Three Switch


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Connecting Devices


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Repeater

Operates at Physical Layer

A Repeater receives a signal and before it becomestoo weak, regenerate the original bit pattern

Does not connect two LANs

It forwards every bit but it has no filtering capability

Repeater do not amplify the signal, it simplyregenerates the signal. If corrupt signal is received,

it copy it Connect segments of LAN

HUB: A multi-port repeater


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Repeater


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Function of a Repeater


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Hub


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Bridge

Operates in both Physical and Data Link Layer

As Physical layer device, it regenerates the signal

As Data link layer device

overcome collision domain restriction

Filtering capability

It check the destination address of a frame and

decide if the frame should be forwarded or dropped Has table which map addresses to ports

A bridge has a table used in filtering decision


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Bridge


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Learning Bridge


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Loop Problem


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Router

Layer three device

At Physical Layer Regenerates the signal

At Data Link Layer Check Physical Address

It can connect

Two LANs

Two WANs

LANs and WANs


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Bus Backbone


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Star Backbone


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Connecting Remote LANs


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A Switch Connecting 3 LANs


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A Switch using VLAN

DCCN Lecture 5 [Compatibility Mode]

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Transcript of DCCN Lecture 5 [Compatibility Mode]