1. Hub v.s. Switch
Qualnet Exercise 1

2. UTP (Unshielded Twisted Pair)
What is Hub (集線器)
A hub is used in a wired network to connect Ethernet cables from a number of devices together.
UTP (Unshielded Twisted Pair)

3. 星狀架構

4. UTP (Unshielded Twisted Pair)
What is Switch (交換機)
A switch is used in a wired network to connect Ethernet cables from a number of devices together.
UTP (Unshielded Twisted Pair)

5. What is Switch
Switches keep traffic between two devices from getting in the way of your other devices using the same network.

6. Hub v.s. Switch Safety Concern Management Concern Efficiency Concern
Switch > Hub
Management Concern
SNMP: Simple Network Management Protocol
Efficiency Concern
No collision
Cost Concern
Hub > Switch

7. Qualnet Practice New scenario
Add 4 devices and 1 hub in the canvas, and link them together
Add 2 CBR flows
Run and See
Analyze the results
Application->CBR Server-> Throughput
Change hub to switch
Compare the results

8. Network Topology Items to send: 0 Item size: 1200 Bytes
Interval: 0.1MS
Start Time: 1S
End Time: 5S
Throughput ?
HUB
Items to send: 0
Item size: 1200 Bytes
Interval: 0.1MS
Start Time: 1.1S
End Time: 5.1S

9. Question
Make the animation slow down, does the 2 CBRs appear at the same time?

10. Question What’s the throughput, if 2 CBR’s interval is 0.1 S ? Hub Lab
What if 2 CBRs start at the same time(1sec)
What’s the throughput, if Hub is 10 M ?
What’s the throughput, if only one CBR exists?

11. Change Hub to Switch
MAC Protocol-> switched Ethernet