Protocols Flashcards
What is a network protocol?
Is an agreed set of rules, on how to communicate over a network. A protocol is often made formal by setting up a world standard
What 6 details should a protocol include?
How to set up a connection How to end a connection How to start a message How to end a message How to deal with corrupted data How to format the data being sent
What do protocols allow hardware makers to do?
Hardware makers can make sure that their devices will work on a network using that protocol
What does TCP/IP stand for?
Transmission Control Protocol / Internet Protocol
What does the TCP/IP protocol do?
Prepares messages for transmission and reassembles any received messages
When sending data, the TCP rules (protocol) include what?
Dividing the message into packets
Adding a sequence number to each packet so the message can be re-assembled
Adding extra error-correction information, so errors can be spotted and fixed
When receiving data the TCP rules (protocol) include what?
Examining each packet for errors by using the extra information that was added to it
Fixing any errors (if possible) or requesting that the packet be re-sent
Spotting missing packets and requesting them to be re-sent
If all packets are present, using the sequence number of each packet to re-assemble the message
When transmitting messages, what is the IP protocol responsible for?
For providing the destination address and to recognise incoming data packets
For sending data the IP rules (protocol) include what?
Add the destination address to each data packet
Add it own address to indicate where it came from
For receiving data packets the IP rules (protocol) include what?
Accept data packets that have its own address attached
Ignore all data packets that do not contain its own address
What does HTTP stand for?
HyperText Transfer Protocol
What does the HTTP protocol underlie?
World Wide Web
What protocol is used when web pages are sent and received?
HTTP
What is a web page made up of?
A collection of individual files - text, images, styling, ETC
What does the HTTP protocol allow the browser to do?
To request individual files from a web server in an orderly way
What happens when the HTTP protocol receives individual files from the web server?
They are rendered into a web page
What does HTTPS mean?
HTTP secure
How does the HTTPS protocol work?
Works like http, but also encrypts web page data before it is sent out of the browser or server, to make sure that nobody can intercept the data and read it themselves
What does FTP stand for?
File Transfer Protocol
What is the FTP protocol used for?
To transfer (i.e. upload and download) files between a client and server on a computer network
What does POP stand for?
Post Office Protocol
What does the POP protocol allow for?
Allows emails to be downloaded and /or deleted from a mail server and viewed offline by an email client
What are the 3 main disadvantages with the POP protocol?
It can only handle one mailbox
Messages, once downloaded, are removed from the email server and cannot later be viewed by other devices
It does not support complex searches of emails on the server
What does the IMAP protocol stand for?
Internet Message Access Protocol
How is the IMAP protocol different to the POP protocol?
IMAP is similar in many ways to POP but it also offers more complex commands to manage emails on the server itself
What does the IMAP protocol allow for
The email to remain on the server even after being downloaded to the device
True or False, you can use multiple devices and access your emails from different devices using the IMAP protocol?
True
What are the 6 things the IMAP protocol allows you to do?
Set flags on emails
Access emails on multiple devices
Synchronisation across devices
Allows complex searches to be carried out based on subject and headers
It can handle more than one mail box
Choose whether to download just the headers, full body or not to download attachments
What does SMTP stand for?
Simple Mail Transport Protocol
What are the 3 email protocols?
POP
IMAP
SMTP
What is the SMTP protocol used by?
The mail server to send and receive emails from all other mail servers across the internet
What is an ethernet, in terms of protocols?
Ethernet is a family of protocols responsible for sending and receiving data along a network cable
Why has an ethernet got more than one protocol?
It works over a range of data speeds
What is ethernet the most popular protocol used for?
For putting together a local area network (LAN)
What 3 parts are there for the ethernet protocol?
Hardware. Specifies the performance expected of network cables, plugs and sockets
Data format. Describes the format of the data packets sent or received over the network
How to deal with data collisions i.e. when two devices send data at exactly the same time
What is Bluetooth?
Is a wireless protocol that was developed to allow devices that are very close to one another to exchange data
What is Bluetooth a collection of?
Specialised protocols that have been combined
What does each layer have in the ‘4 layer model’?
Has a particular function to perform
What is the order of the 4 layer model?
Layer 4 = Application Layer
Layer 3 = Transport Layer
Layer 2 = Internet Layer
Layer 1 = Network
State the most important thing about the 4 layer model
The protocols in each layer can only communicate with those in the layers directly above and below it
What protocols are in the Application Layer?
FTP, HTTP, POP, IMAP, SMTP
What protocol is in the Transport Layer?
TCP
What protocol is in the Internet Layer?
IP
What protocols are in the Network Layer?
ETHERNET, Wi-Fi
