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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