network protocols Flashcards
what is a network protocol?
A protocol is a set of rules for how devices communicate and how data is transmitted across a network.
how is data sent in a protocol?
data sent between networks are split into equal-sized packets. Each packet contains extra information eg. the destination and source addresses and a checksum used to find errors.
how are network protocols organised?
network protocols are divided into layers.
what is a layer?
A layer is a group of protocols that have similar functions.
how many layers are in the TCP/IP model?
there are four layers of
what is layer 1 called and what is its function?
layer 1 is called the link layer.
it is used to pass data over to the physical network
what protocols may be used in layer 1?
wi-fi and ethernet
what is the name of layer 2 and its function?
layer 2 is called the internet layer
— it is used to add IP addresses to data packets, directing them between devices
—They are used by routers.
what protocol may be used in layer 2?
IP
what is layer 3 called and what is its function?(2)
layer 3 is called the transport layer
— it is used to set up communication between a sender and a receiver
— IT is also used for splitting data into smaller pieces
what is layer 4 called and what’s its function? (1)
layer 4 is called the application layer
— it is used for providing networking services to applications — eg. turning data into websites.
what protocols are used in layer 3?
TCP and UDP
what protocols are used in layer 4?
HTTP, HTTPS, FTP, SMTP, IMAP
what are the advantages of using layers?
it breaks network communication into manageable pieces. Which helps developers concentrate on only one area of the network without having to worry about the others.
what is the advantage of layers being self-contained?
layers can be changed without affecting the other layers.
advantage of layers having set rules
having set rules for each layer forces companies to make compatible, universal hardware and software, so different brands will work with each other and always work in basically the same way.
what else is the application layer responsible for ?
files, emails and data transfer
what does HTTP stand for and what is it used for?(2)
it stands for Hyper Text Transfer Protocol.
governs communication between a web server and a client (the web browser)
what does HTTPS stand for and what is it used for?
stands for Hyper Text Transfer Protocol Secure. It is a more secure version of HTTP as it encrypts all information sent and received.
what does FTP stand for and what is it used for? (2)
stands for File Transfer Protocol.
—Used to transfer files like documents, music, or data across a network or the internet
what does IMAP stand for and what is it used for?(2)
Internet Messaging Access Protocol.
—It is used to retrieve emails from a server.
what does SMTP stand for and what is it used for?
Simple Mail Transfer Protocol.
— It is used to send emails
what else does the transport layer do?
controls the packaging and unpackaging of data
what does TCP stand for and what is it used for?
Transmission Control Protocol.
Controls the packaging and unpacking of data using numbered data packages so that no data is lost.
what does UDP stand for and what is it used for?
User Datagram Protocol.
controls the packing and unpacking of data without numbering data packets so it is unreliable and data may be lost.
what is UDP best used for?
Gaming and live video streaming as TCP would take too long to deliver the packets and it is much preferred to have speed rather than 100% reliability when gaming or streaming.
what is TCP best used for?
downloading files as it is preferred to have a reliable connection. Missing data packets can cause files to be corrupted and unusable, but you wouldn’t want to have to redownload the whole file.
what does IP stand for and what is it used for?
Internet protocol.
to deliver data packets from one device to another. they use ip addresses to give a unique name to each packet which directs it to the correct router.
what is Wi-Fi?
Wi-Fi is the standard set of protocols for wireless LANs
— wi-fi is a family of protocols commonly used in WLANs — units sent on the link layer are called frames instead of packets
what two radio frequency bands do wi-fi use?
2.4 GHz and 5 GHz
what are the benefits of both frequencies?
2.4 GHz has a greater range and is better at getting through walls and other obstructions whereas 5 GHz is faster over short distances
how are the radio frequency bands split up?
they are split in to channels that each cover a small frequency range.
what happens when channels overlap
it can cause interference
what is the ethernet used for
handling the transmission of data between devices on LANs, specifically for wired connections.
