Network Design

Question 1

What is the hierarchical design model?

Answer 1

It is a model for designing LANS. It consists of 3 layers.

Access layer - Where end devices connect. Provides access to the rest of the network. Controls which devices connect.

Distribution layer - Aggregates data from the access layer. Transmits data to the core layer to send to its final destination.

Core layer - High speed backbone. Needs to be highly available and redundant. Sends data to its final destination. Focuses on speed rather than security.

Question 2

What are the benefits of a hierarchical network?

Answer 2

• Scalable, expanded easily
• Redundancy. Ensures path availability
• Performance
• Security. Access layer controls what can connect
• Manageability. Each layer has specified role

Question 3

What is a converged network and what are the advantages?

Answer 3

A converged network is one that combines voice, data, and video. Needs QoS (quality of service) to give priority to voice and video.

Advantages

• 1 network to manage them all
• 1 group of people to run the network
• 1 set of cabling for the network
• 1 service provider
• Affordable

Question 4

What is Link Aggregation?

Answer 4

Combining multiple ethernet connections into one logical link

Question 5

List the features of switches in the access layer

Answer 5

• Port security
• VLANs
• Link aggregation
• Power over ethernet
• Quality of service (QoS) gives priority to voice and video

Question 6

List the features of switches in the distribution layer

Answer 6

• Layer 3 support
• High forwarding rate
• Port speed >= 10Gps
• Redundancy
• Quality of service (QoS)
• Security (Access control lists)

Question 7

List the features of switches in the core layer

Answer 7

• Layer 3 support
• High forwarding rate
• Port speeds >= 10Gps
• Redundancy
• Link aggregation
• Quality of service (QoS)

Question 8

What factors need to be considered when choosing switches?

Answer 8

• Cost
• Power over ethernet
• Port forwarding rate
• Link aggregation