KS4 Year 10 MS PowerPoint Presentation on Network Protocols, specifically the Application Layer Protocols.

1. NETWORK PROTOCOLS
FOR KS4
OCR GCSE COMPUTER SCIENCE (J277)
MRS KNIGHT

2. STARTER
NETWORKS . . .
How much can you recall?
Networks, LANs & WANs Quiz
(Google Form)

3. QUICK RECAP OF LAST LESSON
IP Address
Internet Protocol address
Unique address for each device on a
network.
Each address has 4 sets of up to 3 digits
(IPv4), each with a maximum value of 255.
Used to route packets on a WAN.
MAC Address
Media Access Control
Every individual device in the
world has a unique MAC Address. Used to
route frames on a LAN, directed by the switch.
TCP / IP
Transfer Control Protocol / Internet Protocol
TCP - Rules for communicating over the internet.
IP - Rules for communicating over the internet

4. LEARNINGOBJECTIVES
•Define network protocols and why they are needed.
•Identify and explain standard internet protocols in the
application layer, e.g. HTTP, HTTPS, FTP, SMTP, POP, and IMAP.
KEY WORDS:
Protocol, DNS, HTTP, HTTPS, FTP, POP, IMAP,
SMTP, TCP/IP, MAC addresses, layers.

5. SUCCESS CRITERIA
ALL will have a basic understanding of why protocols are used.
ALL will be aware of some protocols and what they are used for.
MOST should be able to explain why protocols are used.
MOST should be able to identify and explain specific protocols.
SOME could give detailed explanations with examples of why
protocols are used. SOME could give detailed explanations for
most protocols.

6. WHAT ARE NETWORK PROTOCOLS?
1. A network PROTOCOL is set of RULES for communication
over a network.
2. This STANDARDISATION allows interoperability between
systems locally and across the globe.
3. Protocols describe HOW the standards work.
QUESTION: Why do we need these standards?

7. 10-MINUTE TASK
CREATE A PROTOCOL
 Get into groups of 3-4
 Create a protocol for
sending simple text messages
across a network.
 Write out the steps that
your protocol will follow to
send the message.
 Test your protocol by
sending a message across your
group.
REQUIREMENTS
1. Send a message of at least 80 characters including
spaces.
2. Split your message into ‘chunks’.
3. Each ‘chunk’ can contain a maximum of 8 characters.
4. ‘Chunks’ might not reach the other computer in order.
5. Both the sender and the receiver of the message must be
confident that the full message has been received.

8. TCP/IP – 4 LAYER PROTOCOL STACK
APPLICATION
LAYER
TRANSPORT
LAYER
INTERNET
LAYER
LINK
LAYER
PROVIDES END-TO-END COMMUNICATION
BETWEEN 2 HOSTS. DETERMINES
LANGUAGE, PACKET SIZE, ETC.
ADDRESSES AND PACKAGES DATA
READY FOR TRANSMISSION.
ROUTES PACKETS ACROSS THE NETWORK.
PHYSICAL HARDWARE, I.E. ROUTERS,
CABLES, NETWORK INTERFACE CARDS (NIC).
DHCP, DNS, HTTP, HTTPS,
FTP, SMTP, POP, IMAP
TCP, UDP
IP4 OR IP6
TWISTED PAIR, WI-FI,
FIBRE.
PROVIDES USER INTERFACE, I.E. WEB
BROWSERS AND EMAIL PROGRAMS.

9. Hypertext Transfer Protocol Hypertext Transfer Protocol
Transfers non-secure web
pages between web servers
and web browsers
(client) across the internet.
The data is not private.
Securely transfers encrypted
web pages between web
servers and web browsers
(client) across the internet.
The data remains private.
HTTP HTTP
VERSUS
HTTP Image courtesy of Rahul Kumar Mandal at medium.com 2021.
HTTP/HTTPS is mainly used to access web pages but is also the
protocol used for various apps too.

10.  Enables sending, receiving and sharing of files across the internet.
 FTP is not encrypted and therefore insecure.
Image courtesy of EDUCBA.COM 2021.
File Transfer Protocol
FTP

11. SMTP
SIMPLE
MAIL
TRANSFER
PROTOCOL
 Used by email client application to send email.
 SMTP server listens for SMTP request from email client.
 SMTP relays emails via email servers throughout the internet.
Image courtesy of GEEKFLARE.COM 2021.

12. Image courtesy of Tech4Law.co.za 2021.
INTERNET
MESSAGE
ACCESS
PROTOCOL
POST
OFFICE
PROTOCOL
IMAP creates a COPY of the email on the device.
IMAP leaves a COPY on the mail server.
After opening the email, it CAN be viewed on
other devices too (unless it is deleted).
POP does NOT create a client copy of the email.
POP does NOT leave a copy on the mail server.
After opening the email, it CANNOT be viewed
on other devices.
VERSUS
POP controls the
fetching/download of
emails from the mail
server to the client.
IMAP controls the
download/upload of
emails to and from the
mail server.

13. SUMMARY - WHY TCP/IP ?
APPLICATION
LAYER
TRANSPORT
LAYER
INTERNET
LAYER
LINK
LAYER
PROVIDES END-TO-END COMMUNICATION
BETWEEN 2 HOSTS. DETERMINES
LANGUAGE, PACKET SIZE, ETC.
ADDRESSES AND PACKAGES DATA
READY FOR TRANSMISSION.
ROUTES PACKETS ACROSS THE NETWORK.
PHYSICAL HARDWARE, E.G. ROUTERS,
CABLES, NETWORK INTERFACE CARDS (NIC).
DHCP, DNS, HTTP, HTTPS,
FTP, SMTP, POP, IMAP
TCP, UDP
IP4 OR IP6
TWISTED PAIR, WI-FI,
FIBRE.
PROVIDES USER INTERFACE, I.E. WEB
BROWSERS AND EMAIL PROGRAMS.

14. RETRIEVAL GRID (PLENARY)
HTTP DNS IMAP
FTP SMTP HTTPS
IP TCP POP

15. RETRIEVAL GRID ANSWERS
HYPERTEXT
TRANSFER
PROTOCOL
DOMAIN NAME
SERVER
INTERNET MESSAGE
ACCESS PROTOCOL
FILE TRANSFER
PROTOCOL
SIMPLE MAIL
TRANSFER
PROTOCOL
HYPERTEXT
TRANSFER
PROTOCOL
(SECURE)
INTERNET
PROTOCOL
TRANSFER CONTROL
PROTOCOL
POST OFFICE
PROTOCOL

16. CONFIDENCE LEVEL?
VERY CONFIDENT
Understood ALL of
it, very confident.
FAIRLY CONFIDENT
Understood MOST of
it, fairly confident.
OKAY
Understood SOME of it
and need some support.
NEXT LESSON: Threats to computer systems and networks.
HOME WORK: Watch video: Threats to Networks (Research threats – google doc).