2.7 - Protocols
2016 - Unit 1
What is a protocol?
A protocol is a set of rules that allow devices on a network to communicate with each other.
TCP / IP is actually two separate protocols that combine together.
Protocols to Transfer Data:
TCP / IP / UDP
TCP is a protocol that allows packets to be sent and received between computer systems.
It breaks the data into packets and reassembles them back into the original data at the destination.
IP is a protocol in charge of routing and addressing data packets. This ensures data packets are sent across networks to the right destination.
It is also an addressing system - every device on a network is given a unique IP address so data packets can be sent to the correct computer system.
UDP (User Data Protocol) is a faster alternative to TCP - it is used where low latency ('low lag') is important, such as online gaming and video chat. However, UDP does not automatically check for errors so packets are more likely to be lost or received out of order.
HTTP is a protocol that can be used to transfer web pages over the Internet so that users can view them in a web browser.
All URLs start with either HTTP or HTTPS (e.g. https://www.csnewbs.com).
HTTPS is a more secure version of HTTP that works with another protocol called SSL (Secure Sockets Layer) to transfer encrypted data.
You should see a padlock symbol in the URL bar if your connection to that website is secure.
(Hyper Text Transfer Protocol)
FTP is a protocol that can be used to transfer files across a network.
ICMP (Internet Control Message Protocol) collects network status information (such as router errors) and is used for troubleshooting.
SNMP (Simple Network Management Protocol) is a protocol that records network statistics, such as router usage.
Network Management Protocols
SMTP (Simple Mail Transfer Protocol) is a protocol used to send emails to a mail server and between mail servers.
POP (Post Office Protocol) is for downloading and storing emails from a mail server.
2.7 - Protocols:
1. Describe each of the following protocols.
Also, state the protocol's full name and draw an icon or diagram for each:
d. HTTP & HTTPS
i. POP 
2. State which protocol would be used in the following scenarios:
a. Transferring a music file to a friend over the internet.
b. Sending an email to a friend in Japan.
c. Checking for errors on a network.
d. Having a video call with a colleague in London.
e. Receiving an email from the bank.
f. Watching a video on YouTube.
g. Checking the statistics of usage on a network