Topic 4.1 - Networks

Question 1

If the network transfer is at 3 Bbps, then construct an expression to show how many bytes can be transmitted in 10 seconds

Answer 1

(3 x 1000^3 x 10) /8

Question 2

When transferring data, describe the process that ensures the data received matches the original

Answer 2

Each packet has a packet header which contains information on how many data packets there are and the packet number so it knows the order to assemble it so the recipient computer can assemble it in the correct order and identify any missing data

Question 3

What is the sequence of processes to open a web page

Answer 3

1. The URL is typed into a web browser address bar
2. the browser locates the IP address using a DNS server
3. the browser sends a request to the web server with the IP address
4. the web server uses HTTP to send back the requested web page
5. the browser displays the content of the page

Question 4

what is the difference between SMTP, POP, and IMAP

Answer 4

-SMTP -simple mail transfer protocol - sends email from device to email server
-POP - post office protocol - retrieve emails from mail server but removes the original copy when it is retrieved by the client
-IMAP - internet message access protocol - retrieves emails but keeps emails on the mail server which prevents different devices from becoming out of sync

Question 5

What organisation do you have to pay to get access to the internet

Answer 5

Internet service provider

Question 5

Describe the role of the transmission control protocol (TCP).

Answer 5

Splits the data into packets (1) and numbers them (1) using a checksum (1) to see if packets have been delivered correctly (1) to avoid error/data corruption detection (1) before reordering them at their destination (1)

-resends packets if found to be corrupt/missing on arrival (1)
-handles handshaking and transmission details (1)
-establishes a dedicated channel between source and destination devices (1)
-communicates with the application layer above and the network layer below (1)

Question 5

what are protocols

Answer 5

it is a common set of rules that allow devices on a network to communicate with each other

Question 6

what items are found in a packet

Answer 6

-Data
-Destination address
-Source address
-Error checking field/checksum
-Timestamp
-Sequence number

Question 7

Advantages of wireless for an organisations offic builidinh

Answer 7

-doesn’t require a specialist to install
-doesn’t require space
-employees and visitors can move around the building without disconnecting