So far in this book, we have made a distinction between real-time and nonreal-time traffic as the major differentiating factor regarding the tolerance toward delay, jitter, and packet loss. We have also kept the traffic flows simple, just a series of Ethernet, IP, or MPLS packets crossing one or more devices.
This is clearly an over simplification, so in this chapter we take one step further by examining some of the more special scenarios. The environment where a QOS deployment is performed, either in terms of the type of traffic and/or type of network present, always needs to be taken into consideration. However, some environments are more special than others due to their uniqueness or just because they are a novelty; as such the authors of this book have selected the following scenarios as the most “special ones” in their opinion, and each one will be detailed throughout this chapter: