YEAR 1 CO1 WEEK 22 NETWORK BASICS AND HARDWARE Flashcards
Advantages of networks
Sharing devices such as printers saves money.
Software licenses cheaper than buying multiple standalone licences.
Files easily shared between users.
Network users can communicate via email and instant messenger.
Security good - cannot see other users files.
Data easy to backup as stored on file server.
Disadvantages of networks.
Purchasing network cabling and file servers can be expensive.
Managing large network complicated - requires training and network manager to be hired.
Viruses can spread to other computers through network.
Danger of hacking particularly with wide area networks.
What is a computer network?
Created when two or more devices are connected to eachother.
Allowed devices to share data and resources.
What is a firewall?
A piece of hardware and or software which monitors traffic coming in or out of a network filtering it.
Describe a PAN network.
A Personal Area Network.
The smallest type of network.
Consists of connected devices are in close proximity to an individual, I.e few metres.
Main technology used in PAN is Bluetooth.
Describe LAN network.
A Local Area Network.
LAN covers small geographical area, I.e may be within same building.
Uses connections that are owned by the organisation.
They are responsible for cost of setting up and maintaining of all parts of LAN.
Describe WAN network.
A Wide Area Network.
A WAN covers a large geographical area connecting two or more LANs together.
These connections may be done via fibre optic cables, satellite communications links or microwave links.
Benefits of LAN.
Resources and files can be shared by users on LAN. Added to shared directories so users with right permission level can access it.
Log onto any workspace on the LAN.
Instead of being restricted to same computer to log onto can access their files logging onto any computer on the LAN.
Peripheral can be shared by users such as printers meaning less equipment needed thud saving money.
Drawbacks of LAN.
Network Failiure if there is a problem with the central file server no one will be able to access their files.
Cost setting up and running a server is expensive.
Benefits of WAN.
Enable LANs to be connected together.
Enable data to be shared between LANs.
Allows workers to collaborate even if they are geographically far apart.
What is a NIC?
Network interface card.
Provides physical connection between network and computer workstation.
(Determines speed/performance of a network)
What is a Hub?
A small box that links nodes together to form a network.
Evey node connected to hub by cable, huns transmit data from one node to another.
This happens with data packets which are small chunks of data which has a destination address included.
What is a Switch?
For larger networks where security is important a switch is better.
Same as a hub but data packets sent to the intended node.
This is done by reading the destination info of the data packets.
Switch knows every node on network due to their MAC addresses.
Hub V Switch.
Hub:
Data packets transmitted to every node on the network.
Risk of data collisions.
Security risk as data sent to all nodes.
Less expensive.
Switch:
Transmitted only to the intended nodes.
Less risk of data collisions.
Better security as sent to right nodes.
More expensive.
What is a Router?
Device that transfers data from one network to another. Often used to connect LANs to form a WAN.
What is the internet?
Worldwide connection of computer networks that are connected together
What is an IP addressed
4 nums that are between 1 and 255
Eg 1.255.34.635
Electronic address
What is IPv6
8 nums that are hex decimals
What is a static Ip address?
Your IP address is yours it’s doesn’t change useful for wedpages
What is a dynamic IP address ?
Changes
What is An ISP?
A company that provides u access to the internet
What is a URL?
Uniform Resource locator
Eg http
Www
ocr.org.uk
What is the DNS look up process?
Domain name sent to DNS
DNS maps this domain to IP adresss
What are the advantages of DNS?
People don’t need to remember IP address
Easily upgradable
What are websites stricter?
Home page - index
Main Sections- site index
Subsections - content
What is local hosting?
Your own pc set up as a web server which other devices can connect to.
Cheaper
What is External hosting ?
Paying a company to host the website
Shared servers - multiple
Dedicated servers - big company’s
What is the cloud?
Network of servers
Some run applications others store data
What are the benefits of the cloud ?
Increased storage cheaply
Access files from anywhere in the world
Collaborate with others from around world
What is a VPN?
Secure tunnel between two or more devices (encrypted)
What are virtual network ?
A smaller part of a LAN or WAN in which specific devices can see each other
