Chapter 9. Lan QoS

QoS Exam Topics

This chapter covers the following exam topics specific to the QOS exam:

• Describe QoS trust boundaries and their significance in LAN-based classification and marking

• Describe and explain the different queuing capabilities available on the Cisco Catalyst 2950 Switch

"Why would I go through the hassle of configuring and managing QoS on my LAN, which is already overprovisioned? If I have to, I will just add more bandwidth!"

This is a common statement. Conventional wisdom dictates, "If you have enough bandwidth, you do not need QoS, which is used only for WAN links that do not have enough bandwidth. LANs have plenty of bandwidth, so you are safe."

Although this sounds reasonable, it is not entirely accurate. Bandwidth is only one of the factors that needs to be taken into consideration for a network that supports real-time applications.

This chapter discusses the QoS features that the Cisco Catalyst 2950 LAN switch offers and examines some recommended configurations designed to prioritized real-time applications across your LAN.