Local area networks Flashcards
what is a network?
computing devices connected with communications channel to share hardware and software resources.
what is a transmission medium?
cables/WiFi point makes transmission possible bounded or unbounded(wireless)
what is LAN?
network capabilities of group of computers near each other to share resources connected to LANs WANs and internet
what are network interface cards
to which network media can connect
what is bounded meia?
cables used as network transmission medium to carry signals between computer and peripherals.
what is bounded medium?
signals confined to medium and don’t leave.
what is bandwidth?
theoretical maximum amount of data travels along cable per unit time.
what is a twisted pair cable?
insulated strands of copper wire twisted around each other.
what do twisted pair cable prevent
electrical interference from adjacent pairs or outside sources.
what is an unshieled twisted pair cable?
several pairs copper cables covered in plastic.
why are UTPs widely used?
easy to install,expand and troubleshoot.
what are UTPs advantages and disadvantages?
cost of cabling is relatively low.
they are easy to install with simpler connections
length can’t be greater than 100 meters.
copper cables have inherent weakness.
what are copper cable weaknesses?
eavesdropping signals can be intercepted by outsiders.
Attenuation signal loses strength over distance
Crosstalk signals from 1 line interfere with signals from another line
Electromagnetic interference signals from nearby sources corrupt signal travelling.
why are fibre optic cables different?
optical fibres carry digital data singals in light pulses which means no electric impulses to steal
what do they consist of
consists of thin glass cylindrical core covered by cladding
what happens when the fibres are made from plastic?
they are easier to install but are unable to carry light pulses for long distances
what is multimode fibre?
larger core used for shorter distances.
what is single mode fibre?
smaller core for longer distances.
what are the advantages and disadvantages?
data trasmitted at high speeds
transmitted over long distance securely
used to connect segments of LAN. more expesnsive than UTP and requites experise to properly install and connect devices.
what does wireless mean?
consists of radio and microwave communication,light,visble and infrared
what is bluetooth?
wireless technology to send data over short distances and it handles data or voice transmissions at same time using little power.
what is near field communication(NFC)
wireless connection between 2 device in close proximity and it is Two-way communication and sends and receives information.
what are Radio waves?
Electromagnetic wave used in communication and data transfer. long wavelengths in Em spectrum and frequency determines distance transmitted.
what are transmission technologies?
point to point and broadcast
what is point-to-point?
directly connects 2 nodes.
what is broadcast
communication channel shred by all devices in network meaning the sender sends signal hear by mutiple parties
what is topology?
physical setup of network as in how devices are connected.
what is start topology
Cable connected to NIC in each computer and other end in port of central device which boost signal coming through using UTP cable.
what is tree topology ?
used as back bone to connect LANs.
what are the advantages and disadvantages of tree topology?
they are Easy to setup and maintain.
a problem with one computer doesn’t affect any other device.
add or removing a node does not upset the network
it is easy to extend if the switch has free ports.
it Requires large amoung of cabling to connect nodes independently switch
switch adds to cost
if the switch fails the whole network fails.
what is bus topology?
the nodes connect off a single cable with a terminator at each end to stop signals boucing out.
what the advantages and disadvantages of bus topology?
Less cable is required which reduces costs.
No switch is needed which reduces costs.
It is easy to extend the network by connection nodes to the cable.
It is difficult to trace faults because all nodes share a common cable.
Fault in main cable shuts down the whole network.
It can get congested because signals from all nodes share a cable.
what is ring topology?
the nodes are connected in a closed loop which means signals travel around in 1 direction past each computer
what is the token ring?
common network using UTp cabling to transmit electrical signals
what is a Fibre Distributed Data Interface?
It uses light instead of electric to transmit over 2 fivre optic cable rings.
what are the advantages and disadvantages of ring topology?
orderly network because every device has opportunity to transmit.
Each node duplictes data signals because there is little signal degradation
Easy to create larger network because signal boosting and fibre optic cable rings.
Malfunctioning workstations creat problem because signals pass each device
Moves,additions and device changes disrupt network
NOdes function as repeater(boost singal) which is expensive
Slower than start topology under load.
what is Hybrid topology?
combination of 2 or more different network topologies.
what are the advantages and disadvantages of Hybrid topology?
They are reliable east arror detecting and trouble shooting
Effective adapted to suti building layouts and equipment. Scalable size can easily be increased
Flexible set up to suit organisation need.
Complex in design
Costly
what is the Ethernet?
it connects nodes in LAN and WAN and enables communication through common protocalit also indicates how devices transmit,format and size data so other devices in same network segment can receive,process and recognise data.
what is INternet prococol address?
numerical lable assigned to devices connected to network
Access internet and ethernet or communicate etween devices on LAN.
What is Media Access control address?
Hardware identification number uniquely identifies devices on network and they are needed to be part of ethrenet LAN
what are Internet protocols
how data transmitted between devices and networks
How errors are controlled and reported on
How data is compressed and how sendin device indicates it finished sending and receiging device communicates received