20 lan hardware overview version a.01 h3065s module 2 slides

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LAN Hardware Overview

Version A.01H3065S Module 2 Slides

2 © 1999 Hewlett-Packard Co.

H3065S A.01

LAN Hardware Components

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A LAN is composed of severalhardware components:

• servers and workstations

• LAN interface cards

• transmission media

• other network devices

- repeaters

- hubs

- bridges

- switches

- routers


H3065S A.01

Transmission Media

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Twisted Pair

Coaxial

Fiber Optic

Woven metal shield

Plastic insulating jacket

Nonconducting insulator

Central copper conduit

Plastic insulating jacket

Central copper conduit

Glass or plastic fiber

insulator cablePhotodiode receiver

Terminator

Light-emitting diodeor laser transmitter


H3065S A.01

LAN Topologies

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Bus

Ring

FileServer

Star

Hub


H3065S A.01

LAN Access Methods

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OriginatingWorkstatio

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Token Passing

Recognizes destination addressCopies messageSends token back to source

Seizes tokenChanges status to frameTransmits dataReceives token backRemoves messageIssues new token

Token

CSMA/CD


H3065S A.01

IEEE 802.3 Standard

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Mainframe

Workstation

Packet travels in

both directions

NetworkPacket

TerminatorTerminator


H3065S A.01

IEEE 802.5 Standard

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Token circulates


H3065S A.01

FDDI Standard

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Dual Attachment Station (DAS)

Dual Attachment Concentrator (DAC)

Primary Ring

Secondary Ring

Single Attachment Stations (SAS)

FDDI Dual Ring

Router

Backbone


H3065S A.01

Repeaters and Terminators

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Repeater

Terminator

Terminator

Signal on wires

Terminators

Repeaters• Repeaters extend the network by propagating signal.• Repeaters Pass all traffic through without error checking. • Repeaters Pass errors and collisions through.

Terminators• Terminators are required at each end of a bus LAN segment.• Terminators absorb the signal on the wire so it does not reflect back.

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H3065S A.01

Hubs

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Hubs• Network signal is automatically repeated across every port• Works like a multi-port repeater• Physical star topology; but is implemented as a logical bus topology• Can easily add/remove nodes without disrupting network • Errors and collisions are passed through• Usually uses twisted pair instead of coax for workstation connections

Hub


H3065S A.01

Bridges and Switches

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Switch Bridge

Bridges• Bridges contain two or more separate interface cards and connect multiple segments on the same network.• Bridges forward frames based on the destination MAC address.• Bridges use “store and forward” to ensure no errors are passed onto another segment.• Bridges do not pass errors or collisions through to another segment.Switches• Switches work similar to a multiport bridge in that they connect multiple “collision domains”.• Switches can maintain simultaneous connections; multiple active circuits allow data to be forwarded in parallel.

Address Table

Card 1 Card 2

080009-1A23C4 080009-234ABC0060B0-7EF226 080009-23EF45080009-987654

080009-1A23C4

080009-23EF45

Card 2

Card 1

0060B0-7EF226

080009-234ABC

080009-987654


H3065S A.01

Routers and Gateways

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Network 128.1.0.0

Network 192.1.1.0

Network 15.0.0.0Network 128.2.0.0

RouterRouter

Routers• Routers connect different networks and different LAN types.• Routers forward packets based on destination IP addresses. • Routers exchange routing information and use this information to build route tables.• Each router has a minimum of two LAN cards; each LAN card has its own IP address.• Routers do not forward broadcast packets; broadcast packets are dropped.

Gateways• Gateways used primarily to implement wide area networks (WANs).

Gateway


H3065S A.01

Pulling It All Together

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Router

GatewayRouter R

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BridgeRepeater

Bridge

Switch

Hub

Dual FDDIRing

TokenRing

20 lan hardware overview version a.01 h3065s module 2 slides

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