Networks Flashcards
The difference between client server and peer to peer networks
The primary difference between these two terms is that, in a peer-to-peer network, every node can ask for assistance and deliver services. While in a client-server network, the client nodes demand services and the server node answers with assistance.
Access control
It is a security concept by which you increase the security of a network by tightly controlling the resources people have access to
Networks
A group of two or more computer devices that are connected by a communication medium allowing the computers to communicate electronically
Uses of networks
Centralisation of data - data stored on ONE server
Communication - telecommunication networks connect people
Accessing resources - share and access resources ( DATA AND INFORMATION, PRINTERS, SHARING SOFTWARE, LABOUR, HARDWARE)
Leisure - Access to entertainment (GAMES, MULTIMEDIA, BOOKS)
Transfer of files - By sharing files, allow users to connect to the same network ( OS utility, Network Attached Storage, WEBSITE, email, DRIVE )
Increased productivity - study productively through ONLINE COURSES
Unshielded Twisted Pair ( RJ45 CONNECTOR )
Twisting of wire helps eliminate interference from signals
ADVANTAGES
Inexpensive and easy to install
Supports fast transmission rates
Widely used and tested
Can be used in a variety of networks
DISADVANTAGES
Susceptible to interference
Crosstalk
Attenuation
SHIELDED TWISTED PAIR
complete opposite of UTP
Fibre Optic Cable ( Used to join LAN )
Consists of central glass surrounded by protective materials
Surrounded by cladding which transmits light pulses rather than electronic signals which eliminate interference
ADVANTAGES
Supports fast transmission rate
More secure than UTP
Transmits over long distances
Light signals are not susceptible
Immune to lightning and electronic surges
DISADVANTAGES
Expensive r purchase and install
Complex to install
Problems with copper cables
ATTENUATION - Signal loses strength
ELECTROMAGNETIC INTERFERENCE - corrupt signals
CROSSTALK - signals in adjacent wires can interfere
EAVESDROPPING - signal can be intercepted
Microwave transmission (long distances)
Terrestrial Microwave - uses line of sight method for data transmission between 2 antennas ( can transmit over 50 km )
Satellite Transmission - uses satellites orbiting the earth to pass and receive communications to the destinations
Transponders - they receive signals and send them to stations on the ground. It converts signals into frequencies and boosts them.
Geo-stationery and low orbit
Geo-stationery - satellites in a fixed position above the earths surface and rotate at the same speed as earth therefore look stationery and they are excellent for TV broadcasting
Low orbit - near to earth’s surface and they are better for interactive communication due to closer distance
Radio wave transmissions ( short distance)
Used by radio, TV, cellphone, Bluetooth, WiFi etc. Travel through walls
