Mapping the TCP/IP model to the OSI model

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. Which OSI layers does the TCP/IP Application layer cover?

A Physical and data link

B Application, presentation and session

2. Which OSI layers does the TCP/IP Network Access layer cover?

A Physical and data link

B Session and presentation

3. Which TCP/IP layer matches the OSI Transport layer?

A Internet

B Transport

4. Which OSI layer matches the TCP/IP Internet layer?

A Network (layer 3)

B Data link (layer 2)

5. The OSI session layer is part of which TCP/IP layer?

A Application

B Transport

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1TCP/IP Application layer		ANetwork Access maps to the OSI Physical and Data Link layers, not the OSI Network layer, which matches TCP/IP Internet
2TCP/IP Network Access layer		BCovers three OSI layers: Application, Presentation and Session
3The OSI Transport layer (layer 4) matches one TCP/IP layer of the same job, which handles end-to-end delivery		COSI Network = TCP/IP Internet (IP)
4The OSI Network layer (layer 3) matches the TCP/IP layer that addresses and routes packets		DCovers two OSI layers: Physical and Data Link
5TCP/IP Application = OSI Application only		EThe TCP/IP Application layer also covers the OSI Presentation and Session layers, not just OSI Application
6TCP/IP Network Access = OSI Network		FOSI Transport = TCP/IP Transport (TCP, UDP)

Definitions

TCP/IP to OSI mapping

Fill in the Blanks

Complete each line of code by filling in the missing parts.

TCP/IP Application = OSI Application, Presentation and _______

Network Access = Physical + _________

TCP/IP Transport = OSI layer _

TCP/IP Internet = OSI _______ layer

TCP/IP has 4 layers, OSI has _

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A m = {}

B m['Application'] = [7, 6, 5]

C m['Transport'] = [3]

D m['Internet'] = [3]

E m['Access'] = [2, 1]

Question 2

A TCP/IP Application: OSI 4-7

B TCP/IP Transport: OSI 4

C TCP/IP Internet: OSI 3

D TCP/IP Network Access: OSI 1-2

Question 3

A tcp = 'Network Access'

B osi = 'Physical + Network'

C print(tcp, '=', osi)

Question 4

A m = {'Application': 3}

B m['Transport'] = 1

C m['Internet'] = 1

D m['Access'] = 3

E print(sum(m.values()))

Question 5

A def to_tcpip(osi_layer):

B if osi_layer in [5, 6, 7]:

C return 'Application'

D if osi_layer == 3:

E return 'Transport'

Answer Key

Mapping the TCP/IP model to the OSI model

Section A: Quick Questions

B — Application, presentation and session

A — Physical and data link

B — Transport

A — Network (layer 3)

A — Application

Section B: Match the Pairs

TCP/IP Application layer → Covers three OSI layers: Application, Presentation and Session

TCP/IP Network Access layer → Covers two OSI layers: Physical and Data Link

The OSI Transport layer (layer 4) matches one TCP/IP layer of the same job, which handles end-to-end delivery → OSI Transport = TCP/IP Transport (TCP, UDP)

The OSI Network layer (layer 3) matches the TCP/IP layer that addresses and routes packets → OSI Network = TCP/IP Internet (IP)

TCP/IP Application = OSI Application only → The TCP/IP Application layer also covers the OSI Presentation and Session layers, not just OSI Application

TCP/IP Network Access = OSI Network → Network Access maps to the OSI Physical and Data Link layers, not the OSI Network layer, which matches TCP/IP Internet

Section C: Definitions

TCP/IP to OSI mapping — Each TCP/IP layer covers one or more OSI layers: Application = OSI application, presentation and session; Network Access = physical and data link; Transport and Internet match one each.

Section D: Fill in the Blanks

TCP/IP Application = OSI Application,
Presentation and Session

Network Access = Physical + Data Link

TCP/IP Transport = OSI layer 4

TCP/IP Internet = OSI Network layer

TCP/IP has 4 layers, OSI has 7

Section E: Spot the Error

C — The TCP/IP Transport layer matches OSI layer 4 (Transport). OSI layer 3 is the Network layer, which maps to the TCP/IP Internet layer. It should be m['Transport'] = [4].

A — The TCP/IP Application layer covers only OSI application, presentation and session (layers 5-7). OSI layer 4 is Transport, which has its own TCP/IP layer. It should be OSI 5-7.

B — TCP/IP Network Access covers the OSI physical and data link layers. The OSI Network layer maps to the TCP/IP Internet layer. It should be 'Physical + Data Link'.

D — Network Access covers exactly two OSI layers: physical and data link. With 3 the total would be 8, but the OSI model has 7 layers. It should be m['Access'] = 2.

D — OSI layer 4 (Transport) maps to the TCP/IP Transport layer. Testing for layer 3 would wrongly return 'Transport' for the Network layer. It should be if osi_layer == 4:.