Summary

In this chapter, you learned about QoS models, tools, and design guidelines, including the following topics:

• Why QoS is important in a converged networkone in which data, voice, and video traffic flows

• The QoS-related requirements of various types of traffic

• The two models for deploying end-to-end QoS: IntServ and DiffServ

• The QoS tools available to implement QoS policies, including the following:

  - Classification and marking Analyzing packets and sorting them into different categories, and then putting an indication of the classification of the packet within the packet header itself
  
  

  - Policing Tools that drop the excess traffic or modify its marking
  
  

  - Shaping Tools that buffer extra data until it can be sent, thus delaying but not dropping it
  
  

  - Congestion avoidance Monitoring traffic loads so that congestion can be anticipated and then avoided, before it becomes problematic
  
  

  - Congestion management Controlling congestion after it has occurred
  
  

  - Link-specific tools Compression (to reduce the bandwidth utilization) and LFI (to reduce the delay experienced)
  
  

  - AutoQoS A simple, automatic way to enable QoS configurations in conformance with the Cisco best-practice recommendations
  
  

• The Cisco QoS Baseline guidelines for classifying traffic

• QoS design guidelines