Network characteristics & protocals

Question 1

What is a standalone machine?

Answer 1

A single computer not connected to anything else

Question 2

What is a network?

Answer 2

One computing device connected to another/others via cable or wireless

• The largest network is known as the internet

Question 3

Advantages of networks

Answer 3

-They can share files
-They can share peripherals (such as printers) and connections to other networks
-You can access files from any computer connected to that network
-Servers can control security, software updates and backups
-Communication with other people e.g. email and social networking

Question 4

Disadvantages of networks

Answer 4

-Increased security risks to data as it’s more widely available
-Malware and viruses spread very easily between computers
-If a server fails, computers connected to it may not work
-Computers may run slower if there is a lot of data travelling through the network

Question 5

What are standards?

Answer 5

Set of hardware and software specifications that allow manufacturers to create products and services that are compatible with each other

• without standards, most devices would not be able to interact or communicate with each other

Question 6

What is a protocol?

Answer 6

A set of rules that allow devices on a network to communicate with each other
-If 2 devices have different protocols, they cannot communicate
-However, if they do, they can exchange information

Question 7

Protocol examples:

TCP/IP and UDP

Answer 7

TCP - transmission control protocol
- responsible for communication over LAN/WAN (Local Area Network, Wide Area Network) provides error free transmission between two routers

IP - Internet protocol
- responsible for communication over LAN/WAN
- routes packets across a Wide Area Network

–> together, they make up the TCP/IP protocol stack, the foundation of communication over the internet

UDP - User Datagram Protocol
- responsible for communication over LAN/WAN
- uses a simple, connectionless transmission model
- an alternative to TCP but has no error checking
- it is used to send short messages using datagrams, where speed is more important than accuracy. Maintains an open 2 way connection, which is ideal for online gaming. Largely obsolete now as it is significantly less reliable than TCP

Question 8

Protocol examples:

HTTP/HTTPS

Answer 8

HTTP - Hyper Text Transfer Protocol
- responsible for web page requests
- a way for a client to send and receive requests and deliver HTML web pages. Fundamental protocol of WWW (World Wide Web)

HTTPS - Hyper Text Transfer Protocol Secure
- responsible for web requests
- the same, except it adds encryption and authentication. Should be used whenever a website deals with sensitive information such as passwords or bank account details

Question 9

Protocol examples:

FTP

Answer 9

FTP - File Transfer Protocol
- responsible for file transfers - used for sending files between computers, normally on a WAN
- often people use FTP clients:software applications that sit on top of the actual FTP protocol
- when you interact with the program, the client generates and sends the appropriate FTP commands

Question 10

Protocol examples:

POP/IMAP/SMTP

Answer 10

POP/IMAP/SMTP are popular protocols used in conjunction with mails servers to deal with email

POP - Post Office Protocol
- responsible for transferring messages from an email-server to an email-client
- retrieves emails from a mail server and transfers them to your device, removing them from the server in the process

IMAP - Internet Message Access Protocol
- enables users to organise messages into folders, flag messages for urgency or follow-up, and save draft messages on the server
- keeps emails on the mail server, maintaining synchronicity between devices

SMTP - Simple Mail Transfer Protocol
- responsible for sending and receiving mail messages
- transfers outgoing emails between servers and from email clients to servers

Question 11

How does TCP/IP work?

Answer 11

TCP / IP is actually two separate protocols that combine.

​​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 correct 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.