CCNP Wireless FAQ: Choosing Your Network Architecture
Q1. If you have one pair of backbone locations that need to be connected, which network architecture is the most appropriate?
Answer: Point-to-point architecture.
Q2. What type of antenna—omnidirectional or directional—does a point-to-point network normally use?
Answer: A point-to-point network normally uses a directional antenna.
Q3. When a microwave signal strikes an obstruction, what always happens to it?
Answer: The signal is always attenuated.
Q4 When a point-to-point network is expanded, what architecture is usually chosen? Why?
Answer: When a point-to-point network is expanded, normally point-tomultipoint architecture is used because it is cost effective for many users and it is easily expanded.
Q5. Why is SNR important in a wireless network?
Answer: SNR(signal-to-noise) ratio is important because high signal strength is not enough to ensure good receiver performance. The incoming signal must be stronger than any noise or interference that is present. For example, it is possible to have high signal strength and still have poor wireless performance if there is strong interference or a high noise level.
Q6. What network architectures use sectors?
Answer: Point-to-multipoint architecture and cellular architecture use sectors.
Q7. What are the consequences of selecting the wrong access point antenna system for a point-to-multipoint network?
Figure: Point-to-Multipoint Network
Answer: Selecting the wrong antenna system in a point-to-multipoint network can result in poor network performance and the need for an antenna system redesign. An incorrect antenna selection can result in low signal levels or high noise levels. Either consequence requires that the antenna system be redesigned.
Q8. What architecture is used to allow frequency re-use while connecting several pointto-multipoint networks?
Answer: Cellular architecture is used to allow frequency re-use while connecting several point-to-multipoint networks.
Q9. What is the primary disadvantage of cellular architecture?
Answer: The primary disadvantage of cellular architecture is the careful frequency planning needed to minimize interference between sectors that use the same frequency.
Q10. What type of network architecture can be used if end users are located close together and have partially obstructed (non-LOS) paths between each other?
Answer: If end users are located close together and have partially obstructed paths, mesh architecture can sometimes be used.
Q11. What type of routing does a mesh network perform?
Answer: A mesh network performs dynamic routing.