Post Midterm: Lecture 10: Wired LANS

Question 1

5 basic components of a wired LAN

Answer 1

Network interface Cards (NIC): has MAC address, built into motherboards
Network Cables: different types of different data transfer rates
Hubs and Switches: links cables from different devices, acts as repeaters
Access Points: uses radio waves to connect wireless clients instead of hubs/switches
Network Operating Systems (NOS): runs on servers and devices, provides directory services about LAN resources

Question 2

2. How does wired Ethernet LAN work? (data transmission that isn’t wifi!)

Answer 2

Ethernet cable is connected directly to a modem (connects home to internet) to a device.

Question 3

3. What is logical topology, what are the 3 types?

Answer 3

Logical: how do computers pass information to each other?
1. sequential
2. broadcast (all at once)
3. point to point (dedicated circuit between 2 devices)

Question 4

What is a physical topology, what are the 3 types?

Answer 4

how are computers connected to each other?
1. bus
2. ring
3. star (single point of failure, all connected to hub separately)

Question 5

CSMA/CD (Carrier Sense Multiple Access Collision Detection)

Answer 5

1. computer listens to see if another computer is transmitting
2. all computers have access to the network medium
3. if collision is detected, both wait random amount of time before resending

Question 6

What causes a collision (CSMA/CD)?

Answer 6

two pc’s sense empty line and send at the same time

Question 7

what is shared ethernet?

Answer 7

all connected devices can communicate with each other, no decisions are made about traffic

Question 8

what is switched ethernet?

Answer 8

switch reads destination address of frame and only sends to corresponding port

Question 9

how do ethernet switches know where to send packets?

Answer 9

read source MAC address, sends to corresponding port number

read destination MAC address, if not in table, broadcasts to all ports

wait for destination computer to respond, REPEAT