Network Protocols and Characteristics

Networks: GCSE Recap to start

Open Ended

What is a network?

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•A single computer not connected to
anything else is known as a
standalone machine.

•Once you connect one computing
device to another, either via cable or wireless, you have a network.

What is a network?

Poll

Networks come in all shapes and sizes? Be prepared to give an example

• Yes

• No

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•A single computer not connected to
anything else is known as a
standalone machine.

•Once you connect one computing
device to another, either via cable or
wireless, you have a network.

•Networks come in all sizes:

oSmall business networks with a
handful of devices.

oLarge corporate networks with
thousands of devices.

oThe largest network in the
world – the internet.

What is a network?

Open Ended

Give 2 advantages and 2 disadvantages of being on a network

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

Advantages and disadvantages of networks

• Users can share files.
• Users can share peripherals and connections to other networks such as the internet.
• Users can access files from any computer on the network.
• Servers can control security, software updates and backup of data.
• Communication with other people – e.g., email and social networking.

Advantages

• Increased security risks to data.
• Malware and viruses spread very easily between computers.
• If a server fails, the computers connected to it may not work.
• Computers may run slower if there is a lot of data travelling on the network.

Disadvantages

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•In the field of computer science,
establishing standards is vital.

•Standards are a set of hardware and software specifications that allow manufacturers to create products and services that are compatible with each other.

•Without standards, most devices wouldn’t be able to interact or
communicate with one another.

The need for standards

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•If one devices recognises the binary
sequence 01000001 as A, we need
other devices to recognise the same
sequence as A too.

Standards in use – Character sets

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•HTML is an example of an early
standard adopted within the World
Wide Web (WWW) for the display of
web pages in browsers.

Standards in use – Web pages and HTML

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•A key way of ensuring
technology-based standards are
established and adhered to is to use
protocols.

•Much like spoken languages, if two
devices have different protocols,
they cannot communicate.

•However, if two devices share the
same protocol, they can exchange
information – in other words, they
speak the same language.

What is a protocol?

Open Ended

List 3 network protocols that you saw at GCSE

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

Common protocols

The OCR clarification document states:

“Candidates should be able to discuss examples of protocols
that may be used in a network/the internet (but will not be
asked to recall information about any specific protocol).”

However, they do not go on to list any example protocols.

Based on previous exam papers and other exam board
specifications, we will briefly discuss nine of the most common
that are used for:

• Communication over LAN/WAN
• Web page transfer
• File transfer
• Email

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

Common protocols

Protocol acronym

Protocol full name

Area/purpose

TCP

Transmission Control Protocol

Communication over LAN/WAN

IP

Internet Protocol

Communication over LAN/WAN

UDP

User Datagram Protocol

Communication over LAN/WAN

HTTP

Hypertext Transfer Protocol

Web page requests

HTTPS

Hypertext Transfer Protocol Secure

Web page requests

FTP

File Transfer Protocol

File transfers

POP

Post Office Protocol

Email

IMAP

Internet Message Access Protocol

Email

SMTP

Simple Mail Transfer Protocol

Email

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•The Hypertext Transfer Protocol
(HTTP) is a way for a client and
server to send and receive requests
and deliver HTML web pages.

•It is the fundamental protocol of the
World Wide Web (WWW).

•The Hypertext Transfer Protocol
Secure (HTTPS) is effectively the
same as HTTP, except it adds in
encryption and authentication.

•HTTPS should be used whenever a
website deals with sensitive
information such as passwords or
bank account details.

HTTP/HTTPS

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•The File Transmission Protocol (FTP)
is a protocol used for sending files
between computers, normally on a
wide area network (WAN).

•Often people use FTP clients –
software applications that sit on top
of the actual FTPprotocol.

•When you interact with the program,
the client generates and sends the
appropriate FTP commands.

FTP

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

POP/IMAP/SMTP

Computer

Mail
server

Mail
server

The

internet

Mail
server

Mail
server

SMTP

SMTP

SMTP

SMTP

SMTP

•Three popular protocols are used in
conjunction with mail servers to deal
with email.

•Mail servers can be thought of as a
virtual post office handling incoming
and outgoing email.

•Simple Mail Transfer Protocol
(SMTP) transfers outgoing emails
between servers and from email
clients to servers.

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

POP/IMAP/SMTP

Computer

Computer

Mail
server

Mail
server

The

internet

Mail
server

Mail
server

SMTP

SMTP

SMTP

SMTP

SMTP

POP3

POP3

POP3

POP3

POP3

•Three popular protocols are used in
conjunction with mail servers to deal
with email.

•Mail servers can be thought of as a
virtual post office handling incoming
and outgoing email.

•Simple Mail Transfer Protocol
(SMTP) transfers outgoing emails
between servers and from email
clients to servers.

•Post Office Protocol (POP) retrieves
emails from a mail server and
transfers them to your device,
removing them from the server in
the process.

OCR H046/H466

SLR11 Networks | Network characteristics and protocols

•Three popular protocols are used in
conjunction with mail servers to deal
with email.

•Mail servers can be thought of as a
virtual post office handling incoming
and outgoing email.

•Simple Mail Transfer Protocol
(SMTP) transfers outgoing emails
between servers and from email
clients to servers.

•Post Office Protocol (POP) retrieves
emails from a mail server and
transfers them to your device,
removing them from the server in
the process.

•Internet Message Access Protocol
(IMAP) keeps emails on the mail
server, maintaining synchronicity
between devices.

POP/IMAP/SMTP

Computer

Computer

Mail
server

Mail
server

The

internet

Mail
server

Mail
server

SMTP

SMTP

SMTP

SMTP

SMTP

POP3

POP3

POP3

POP3

POP3

IMAP

IMAP

IMAP

IMAP

Multiple Choice

Provides the rules for file transfer between computers.

• FTP

• FPS

• HTTP

• SMTP

• UDP

Multiple Choice

Provides the rules to be followed by a web server and a web browser when requesting and supplying data.

• FTP

• SFTP

• HTTP

• HTTPS

• SMTP

Multiple Choice

Ensures that communication between a host and a client are secured by encrypting communications.

• FTP

• HTTPS

• USD

• URL

• HTTP

Multiple Choice

A protocol that downloads emails onto a client computer and removes the mail message from the mail server.

• SMTP

• SFTP

• POP

• IMAP

• HTTPS

Multiple Choice

A protocol that allows email messages to be read and stored on a messaging server.

• SMTP

• SFTP

• POP

• IMAP

• HTTPS

Multiple Choice

Which protocol would be most suitable if you needed to access your emails from multiple devices?

• IMAP

• POP3

• SMTP

• FTP

Multiple Select

Network protocols allow data to be sent...

• Securely

• Effectively

• Consistently

• With no mistakes

Multiple Choice

What does TCP stand for?

• Transcript Control Protocol

• Transition Control Protocol

• Transmit Control Protocol

• Transmission Control Protocol

Multiple Choice

Which protocol holds the email until you actually delete it?

• POP3

• IMAP

• SMTP

• FTP

Multiple Choice

Which protocol holds the email only until you receive it?

• SMTP

• FTP

• IMAP

• POP3

Multiple Choice

What is the minimum number of computers needed to create a network?

• 1

• 2

• 3

• 4

Multiple Choice

What is a network protocol?

• A shape of a network, such as star

• A set of rules for sharing data

• The requirements for passwords, such as length

• The size of a network, such as WAN