TCP/IP model

Question 1

acroynm for model

Answer 1

ATIL (DP)

Application, Transport, Internet, Link (Datalink & Physical) [in reverse layer order]

Question 2

Layer

Link

(Layer 0)

Answer 2

Comprised of Datalink & Physical

Protocols include Ethernet.

Question 3

Layer

Internet

(Layer 1)

Answer 3

• Adds source & destination IPs to packets.

transport added dest. port number, so we now have a socket. (ip+port)

Routers operate at this layer.
Protocols include IP.

Question 4

Layer

Transport

(Layer 2)

Answer 4

• Maintain E2E communication
• Splits data into packets and packet metadata
• Adds port information to packets, creating sockets.

(a socket is an ip address + port)

Firewalls operate at this layer.
Protocols include TCP or UDP.

Question 5

Layer

Application

(Layer 3)

Answer 5

• Uses relevant protocols for application.

Protocols include HTTP(S), FTP, etc

Question 6

Explain

Which protocol does the Application layer use?

Answer 6

variable, depends on application, e.g. HTTP(S), FTP, etc

Question 7

Explain

Which protocol does the Transport layer use?

Answer 7

TCP, UDP

Question 8

Explain

Which protocol does the Internet layer use?

Answer 8

IP

Question 9

Explain

Which protocol does the Link layer use?

Answer 9

Ethernet.

Question 10

Recall

Which model is more popular — TCP/IP, or OSI?

Answer 10

TCP/IP.