Connectivity - Communication Protocols

Question 1

Which communication protocol allows someone to make a telephone call via the internet? (sending audio over internet)

Answer 1

VoIP (Voice over Internet Protocol)

Question 2

State 2 pieces of equipment (peripherals) that you might use to make a VoIP call

Answer 2

• Headset / Headphones/ Earphones/ Earpiece
• Microphone
• VoIP phone
• Webcam (web camera)
• Speakers

Question 3

Why might the quality of a VoIP call be lower than the quality of a normal phone call (e.g. land line / 3G / 4G)?

Answer 3

• Low bandwidth (of internet means less data can be sent)
• High latency (the time between data leaving device and arriveing can be long)
• Interference
• Blocked signal
• Other apps are using the connection
• Other people are using the connection

Question 4

What is the protocol for sending email?

Answer 4

SMTP (Simple Mail Transfer Protocol)

Question 5

What are the 2 protocols for downloading emails?

Answer 5

• IMAP (Internet Message Access Protocol)
• POP3 (Post Office Protocol)

Question 6

Describe the difference between IMAP and POP

Answer 6

• IMAP protocol synchronises emails (on all authenticated devices).
• IMAP keeps a copy of an email on both the server and thr device after the email has been downloaded
• POP3 deletes mail from server after it has been downloaded by client onto a device

Question 7

Name 2 drawbacks of IMAP?

Answer 7

• You need an internet connection to access your emails (they cannot be read offline)
• The mail server might get full and you need to get more space by either deleting old emails or paying for more space

Question 8

What are 2 drawbacks of POP3?

Answer 8

• Sent items are only available locally, there is no copy of the email saved on the server
• You cannot access your emails on more than one device
• The speed of downloading mail is dependant on yout internet bandwidth, which means large attachments could take a long time to download

Question 9

What is a benefits of POP over IMAP?

Answer 9

Mail always available on the computer/device for offline consultation.

Question 10

What is a benefit of IMAP over POP?

Answer 10

Email is available on multiple devices

Question 11

What is the protocol to transfer data over the internet?

Answer 11

HTTP

Question 12

What is the difference between HTTP and HTTPS?

Answer 12

HTTPS encrypts data before it is sent over the internet

Question 13

What is Bluetooth?

Answer 13

A type of wireless connection

Question 14

How do you know if a website is using HTTPS?

Answer 14

HTTPS will show in the address (URL) bar of the website. It is often coloured green

Question 15

What protocol do websites use to send data over a network?

Answer 15

HTTP or HTTPS

Question 16

How does encrytion keep data secure?

Answer 16

The data that is being sent is scrambled and encoded and only the server and your computer can decode the data using an encrytion key they both agree on