CHAPTER 4

1. a)At what layer is the 100BASE-TX standard?

b)What can you infer from the name 100BASE-TX?

c)Distinguish between baseband and broadband transmission.

d)Why does baseband transmission dominate for LANs?

e)What is 10/100 Ethernet?

f)What is autosensing?

g)What is Fast Ethernet?

2. a)What is the purpose of the preamble and start of frame delimiter fields?

b)Why are Ethernet addresses called MAC addresses or physical addresses?

c)Is there a minimum length for the data field?

d)If the data field is 40 octets long, how long a PAD field must the sender add?

e)If the data field is 400 octets long, how long a PAD field must the sender add?

f)What is the purpose of the frame check sequence field?

g)What happens if the receiver detects an error in a frame?

3. a)Which is likely to have less latency—a cut-through switch or a store-and-forward switch? Explain.

b)What is the advantage of the other mode of operation?

c)Is determining which mode of operation a switch uses a major purchasing criterion today?


Design Question

1. You will create a design for a network connecting four buildings in an industrial park. Hand in a picture showing your network. There will be a core switch in each building.

Ø  Building A is the headquarters building.

Ø  Building B is 85 meters south and 90 meters east of the headquarters building. From the headquarters building,

Ø  Building C is 150 meters south of the headquarters building.

Ø  Building D is 60 meters west of Building C.

Ø  Computers in Building A need to communicate with computers in Building B at 60 Mbps.

Ø  Computers in Building A need to be able to communicate with computers in Building C at 300 Mbps.

Ø  Computers in Building A must communicate with computers in Building D at 50 Mbps.

Ø  Computers in Building C must communicate with computers in Building D at 75 Mbps.

Ø  Building A will connect directly to Buildings B and C.

Ø  Building C will connect directly to Building D.

a)Specify the standard you will use to connect Building A to Building B.

b)Specify the standard you will use to connect Building A to Building C.

c)Specify the standard you will use to connect Building C to Building D.

Chapter 4-2