TCP/IP layer

Question 1

What does the application layer do?

Answer 1

Interacts with user to provide access to services and data sent/received over the network
where applications operate (eg: web browser and email clients)
requests made to web server or where emails are sent/received

Question 2

What are the protocols in the application layer

Answer 2

HTTP, FTP, Email protocols (SMTP, POP3, IMAP)

Question 3

What does the transport layer do

Answer 3

Concerned with host to host communication
Agree on setting such as ‘language’, size of packet
When sending data
-data from application layer divided into packets of right size, and checksum applied
-Resend packets if not arrived safely
When receiving data
–Perform checksum, and if correct send acknowledgment to sender, if incorrect send request for resend
-Assembles packets in order of packet sequence number and sent to receiver’s application layer

Question 4

What are protocols in the transport layer

Answer 4

TCP and UDP

Question 5

What does the Internet layer do

Answer 5

Adds source and destination addresses to packets from transport layer
Deals with sending data across networks (possibly Internet), from source to destination-routing
When packet received destination address checked, if matches then sent to transport layer

Question 6

What are the protocols in the Internet layer

Answer 6

IP

Question 7

What does the Data link layer do

Answer 7

Controls transmission, reception of data to/from a local network using protocols of a specific network
Where network interface card (NIC) and device drivers are

Question 8

What are protocols used

Answer 8

Ethernet