Welcome to our presentation

Think unique Build unique

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Group memberA.K.M. Asaduzzaman Kaushik Roy Md.Zahid Hasan MD.Asif Al Fahad

Topics

Network Topology

Cables

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Network

LANs and WANs - Geographical coverage

LANs A single geographical location, such as office building,

school, etc

Typically High speed and cheaper.

WANs Spans more than one geographical location often

connecting separated LANs

Slower

Costly hardware, routers, dedicated leased lines and complicated implementation procedures.

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Network Topologies

Ring Topology

Logical ring

Meaning that data travels in circular fashion from one computer to another on the network.

Typically FDDI, SONET or Token Ring technology are used to implement a ring network

Ring networks are most commonly wired in a star configuration

Token Ring has multi-station access unit (MSAU),equivalent to hub or switch. MSAU performs the token circulation internally.

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Ring Topology

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Advantages DisadvantagesCable faults are easily located, making troubleshooting easier

Expansion to the network can cause network disruption

Ring networks are moderately easy to install

A single break in the cable can disrupt the entire network.

Star Topology

All computers/devices connect to a central device called hub or switch.

Each device requires a single cable

point-to-point connection between the device and hub.

Most widely implemented

Hub is the single point of failure

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Star Topology

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Advantages Disadvantages

Easily expanded without disruption to the network

Requires more cable

Cable failure affects only a single user

A central connecting device allows for a single point of failure

Easy to troubleshoot and isolate problems

More difficult to implement

Bus topology Uses a trunk or backbone to which all of the

computers on the network connect.

Systems connect to this backbone using T connectors or taps.

Coaxial cablings ( 10Base-2, 10Base5) were popular options years ago.

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Bus Topology

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Advantages Disadvantages

Cheap and easy to implement Network disruption when computers are added or removed

Require less cable A break in the cable will prevent all systems from accessing the network.

Does not use any specialized network equipment.

Difficult to troubleshoot.

Mesh Topology Each computer connects to every other. High level of redundancy. Rarely used.

Wiring is very complicated

Cabling cost is high

Troubleshooting a failed cable is tricky

A variation hybrid mesh – create point to point connection between specific network devices, often seen in WAN implementation.

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Mesh Topology

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Advantages Disadvantages

Provides redundant paths between devices

Requires more cable than the other LAN topologies

The network can be expanded without disruption to current uses

Complicated implementation

Wireless media

Three types: Radio wave Infrared Microwave

Speeds of wireless solutions don’t keep pace with cable solutions

Installation and maintenance are far more complicated and costly.

Some solutions require line-of-sight, such as infrared and microwave.

Zahid Hasan

142-15-3466

Twisted pair is made of insulated copper wires that have been twisted around each other to form wire pairs

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Twisted-Pair Cables

Unshielded Twisted-Pair (UTP)

Typically wrapped inside a plastic cover (for mechanical protection)

A sample UTP cable with 5 unshielded twisted pairs of wires The common use for this type of cable is telephone wiring

and LAN communications.

18MetalInsulator

Shielded Twisted-Pair (STP) STP cables are similar to UTP cables, except there

is a metal foil or braided-metal-mesh cover that encases each pair of insulated wires

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Coaxial Cables In general, coaxial cables, or coax, carry signals of

higher freq (100KHz–500MHz) than UTP cables

Outer metallic wrapping serves both as a shield against noise and as the second conductor that completes the circuit

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Fiber-Optic Cables

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An optical fiber consists of a core (denser material) and a cladding (less dense material)

Simplest one is a multimode step-index optical fiber Light bounces back and forth along the core Common light sources: LEDs and lasers

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Cross Over and Straight Through

Cross-over: A cross-over cable is used to connect two computers via their NICs, without using a hub or switch.

Straight-through: A straight-through network cable is just what the name implies, a cable that passes data straight through from one end to another. Straight-through cables are used for a variety of connections.

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Advantages and Disadvantages Noise resistance ― external light is blocked by outer

jacket Less signal attenuation ― a signal can run for miles

without regeneration (currently, the lowest measured loss is about ~4% or 0.16dB per km)

Higher bandwidth ― currently, limits on data rates come from the signal generation/reception technology, not the fiber itself

Cost ― Optical fibers are expensive Installation/maintenance ― any crack in the core will

degrade the signal, and all connections must be perfectly aligned 24