Introducing
Your new presentation assistant.
Refine, enhance, and tailor your content, source relevant images, and edit visuals quicker than ever before.
Trending searches
Unit 1: 2.7 - Protocols
110
2.7 - Protocols
Revise, Recap, Review
In pairs, use your scrabble boards to write down as many key words that you have learned since September as you can remember.
Use the table to work out your score for each word.
Objectives
Lesson Objectives
To be able to explain what the term protocol means
To examine the TCP/IP protocol
To be able to give examples of other communication protocols and explain why they are important.
The Internet
The internet is the largest network on the planet.
I can access it on my Apple Laptop, my Windows PC, my Samsung tablet, my Sony Playstation etc.....
How is it possible that all of these different devices from different companies can access the same internet?
Theory
Because the internet operates using worldwide protocol's!
Question
What is a protocol?
TCP/IP
Main protocol for handling internet traffic
Comprised of two different protocols - TCP and IP
TCP
Transmission Control Protocol
Prepares data for transmission and reassembles any received data.
When transmitting the protocol:
Dividing the message into packets
Adding a sequence number to each packet so the message can be re-assembled
Adding extra error-correction information such as a check sum, so errors can be spotted and fixed
When receiving data...
Examines 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
The assembled message is sent to the identified port for use by the application servicing that port
IP (internet protocol_)
Responsible for providing the destination address and to recognise incoming data packets.
For sending data the IP protocol:
Adds the destination address to each data packet
Adds it own address to indicate where it came from - why do you think it needs this?
When receiving data...
For receiving data packets the IP protocol:
Accepts data packets that have its own address attached
Ignores all data packets that do not not contain its own address
Task
Complete worksheet 1
Layers
Protocols are classified into layers according to what they do.
Each layer can only communicate with layers above and below it.
Using this model helps us to understand the complex relationships between protocols used to communicate over networks
Layers
Protocols
TCP/IP is just one of many protocols that are used to help standardise communication
In pairs, come up with a list of 'things' that you think would require a protocol
HTTP/HTTPS
Web pages are made up of text, image files, sounds files, video files etc..
The HTTP (Hyper text transfer protocol) protocol is a set of rules that dictates how clients communicate with web servers
HTTPS is a secure version of the protocol that encrypts data before it is sent out of the browser
FTP
The file transfer protocol is used when uploading and downloading files between a client and a server
This protocol is built into most web browsers to allow you to download your favorite music, or upload an image to snapchat, for example.
Email protocols
There are many protocols that can be used to manage emails
POP (Post Office Protocol) is a basic mail protocol that allows messages to be downloaded and then deleted from a server.
Emails are 'popped' off the server, once it has been read, it can't be accessed from the server again
IMAP
IMAP (Internet Message Access Protocol) allows mail to be read from a server, but the message remains
This means that more than one device can view the email, as it remains on the server to be downloaded again.
SMTP
Simple Mail Transfer Protocol is the set of rules that allows SERVERS to send messages between each other.
The other mail protocols have been concerned with the sender, this protocol defines how those messages are exchanged between servers!
Simple Network Management Protocol
SNMP is a protocol used to gather information and configure about devices on a network
We can use SNMP to view statistics about devices such as routers and printers and to alter their settings remotely
It would be difficult to manage a large network such as this school LAN if you always had to go to each device individually to change it's settings!
Internet Control Message Protocol
ICMP is used on IP networks to generate and send error messages back to the source address
For example you may receive an error to say that the source is un-reachable
Ping!
User Datagram Protocol
UDP is an alternative communication protocol to TCP.
Used for low latency connections - when speed is important!
BUT it achieves it's extra speed at the expense of reliability - It JUST sends the data - no error checking or sequence numbers - This means errors can occur and data may be out of order!
UDP
UDP is fine when losing small bits of data doesn't massively affect us i.e. in a video call or online gaming
Used in applications when speed is our primary concern
Task
Use the Success Criteria to create a poster/kahoot on protocols.