matric networking Flashcards
centralised networks
single server responsible for some/all of processing
server used for applications, data storage, facilities
less powerful work stations connect to the server
decentralised networks
workload distributed among several machines instead of relying on single sever
desktops + laptops
Extra power is used for distributed processing
distributed processing
computer systems that utilise more than 1 computer to run a single application
detect idle CPUs on the network in a locate programs to utilise them.
Includes parallel processing
thin clients
desktop terminal w no hard drive
all features stored on desktop pc stored in server
used as PC replacements to provide cost effective way to create network
benefits: cost (inexpensive) , security, manageability, scalability
fat clients
networked computer where required software is stored locally, minimal dependence on network resources
preferred over thin clients- computers can be customised + configured
smart clients
data stored remotely on internet but use processing power + other resources of local device
eg, google applications (drive,earth)
peer to peer file sharing
P2P
each computer acts as a server (peer) , making communication a 2-way street
p2p advantages
- easy, quick file sharing over large distances
- reduced costs as no need to get separate computer for server
-adaptability : easily include new clients
-reliability: remain functional even if central server crashes
-high performance: improved performance when new client joins as each client is a server and contributes resources
p2p disadvantages
-easy to make files sharable without realising it
-security risks
malware
BitTorrent
p2p protocol
multiple peers downloading and uploading same torrent (swarm) transfer data between each other w/o need for central server
larger files split up into smaller parts to increase speed
once peer has the complete file- it becomes a seed which can be used by other peers ( more seeds- faster peers can download+ share files)
-BitTorrent tracker - server assists in communication between peers - records which peer machines have file copies + peers accessible at time of request and helps co-ordinate efficient transmission + reassembly of file
remote access
ability to access a device from a remote location
only works if host computer is powered on, connected to internet and running sharing software
computer at risk of malware, data loss
VPN
virtual private network
connects remote users to a private internal network using internet
protection - device on vpn becomes invisible to rest of internet users
anonymity -vpn replaces devices ip address w ip address of device providing vpn
censorship- country, bypass restrictions
remote access of network resources , reduced costs
risks: vpn service can track what you do on web while using, leaks can occur if poorly configured encryption
IoT
-internet of things
system of related computing devices, digital machines, objects + people with unique identifiers and ability to transfer data without human interaction
devices - SoC devices (System on Chip)
devices can have identification chip, built in sensors
thing - object that can be assigned IP address
advantages of IoT
cost saving, saved time, improved quality-of-life, increased productivity, efficiency, automation
disadvantages of IoT
replaced many jobs
challenging to manage large no. of devices connected
hacking
difficult for devices from different manufacturers to to communicate
surface web
part of web indexed by search engines + searchable w standard web search engines