networks Flashcards
what is a network?
a network is more than one computer system connected together allowing for communication and sharing of resources.
what is a LAN?
local area network, which has a small geographical close area usually like a school. small site or even within the same building.
the network infrastructure of a LAN
the network infrastructure of a LAN is usually managed and owned by the network owner
what is a WAN?
a wide area network has computer systems situated geographically distant to each other.
what are the factors that affect the performance of a network?
bandwidth and number of devices connected.
As more devices are added to the network, the demand for bandwidth and other resources increases, which can cause slower data transfer speeds and more network congestion.
advantages of a client network server
advantages
controlled from the server to back up data and update software.
hardware software and resources can be shared across a network such as data files
improved scalability as more clients can easily be added to the server.
disadvantages of a client network server
large amounts of network congestion will cause the network to slow down
whole network fails if fault occurs in the server.
malware such as viruses can be spread quickly across the network.
what is a client network server?
client makes a request to the server and the server manages that request and responds.
what is a peer to peer network?
for peer to peer networks data is shared directly between systems without requiring a central server.
advantages of a peer to peer network
simple network to set up as no server is involved
clients are not dependent on a server
can quickly share files between systems
disadvantages of peer to peer networks
no central device to manage security and backups
performance will decrease as more devices are connected to a network
what are data packets?
files that are broken down into smaller parts called data packets so it allows data to be transferred quickly across a network.
what is a star topology?
each computer system is connected to a central hub or switch and transfers its data packets there.hub or switch looks at destination address and sends the data packets there.
advantages of star topology
improved security as data packets are sent directly to and from switch/hub
new systems can be added without the full system needing to be shut down
transfer speeds are fast as minimal network collisions
what is a mesh topology?
data packets transferred along the quickest path to the destination address if pathway is broken there are man alternative pathways.
advantages of mesh topology
data packets can take alternative route if cable/system is broken
they can withstand large amounts of data traffic
new systems can be added without disrupting entire topology
disadvantages of mesh topology
expensive to install because of large amounts of cables required
cables connected to other systems that wont ever need to communicate.
what can affect performance of a network?
bandwidth available
number of users
interference
CPU performance
amount of data to transfer
signal strength
number of data collisions
role wireless access point?
provides a link for wireless and wired networks.creates a wireless local area network which allows wife enabled devices to connect to a wired network
role of the router
routers are used to transfer data packets between networks
routers receive data packets and use the IP address stored in the packet header to determine the quickest rout to its destination
role of a switch
used to connect devices together on a LAN receives data packets and forwards them directly to there destination. also creates a mac address of all the devices connected scans for a matching address before sending the data packet.
role of the network interface card
NIC is an internal piece of hardware needed for the computer to connect to the network
types of transmission media and there characteristics
Ethernet cables-used typically on a LAN to transfer data between nodes and switches
fibre optic-very fast but more expensive and very fragile typically used to send data quickly along a WAN
coaxial cables-older,slower,copper cables not typically used as they can be interfered by electromagnetic interference
what is the internet?
the internet is a global network of interconnected networks
what is a DNS server
a DNS server stores a list of domain name and a list of corresponding IP addresses where the website is stored
what are the steps taken to display a web page?
1.a domain name is typed into an address bar in the browser
2.a query is sent to a local DNS server for the corresponding IP address of the domain name
3.DNS server will check if they hold the IP address of the corresponding domain name. if it does it will pass it to your browser
4.the browser then connect to the IP address of that server and access the website
what is cloud storage?
cloud storage is where you can store data on a server.
advantages and disadvantages of cloud storage
advantages
-huge capacity
-relatively cheap
-great for large companies
-accessible from anywhere
-convenient
disadvantages
-relies on wifi so if no wifi you cant access files without it
-security problems on who owns which files can lead to legal issues
-cant be accessed if server goes down
-vulnerable to cyber attacks could lead to a loss of files
benefits and drawbacks of wired connections
-restricted movement as it is wired
-faster
-more secure
-nic required
benefits and draw backs of a wireless connection
-freedom of movement
-slower
-WNIC required
-less secure
-more convenient
what is a protocol?
a protocol is a set of rules that allow a device on a network to communicate with each other
what is TCP/IP?
TCP/IP is two separate protocols
TCP allows packets to be sent and received between computer systems it breaks data into packets and re assembles them back when at destination
IP ensures data packets are sent to the right destination it is also a addressing system by giving every device on a network a ip address so data packets can be sent to the right location
what is HTTP
HTTP is used to transfer web pages over the internet so that a user can view them in a web browser
what are the different transfer protocols?
FTP- used to upload or download files to/from a web server
SMTP-send emails to a mail server
POP and IMAP-receiving and storing emails from a mail server
format of IP addresses
two versions IPv4 and IPv6
IPv4-uses 32 bit address allows for 4 billion unique addresses uses a decimal point to separate digits
IPv6-128 bit address
MAC address
mac address cant change like IP address mac address is a unique hexadecimal number
benefits of using layers
simplifies designs and makes it easier to use and modify
