Chapter 12: Managing Service Quality

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12.1 Introduction

Packet networks have become popular in recent years as the means of extending mission-critical applications across the enterprise, including remote branch offices, telecommuters, and mobile professionals. The choice of infrastructure will boil down to the IP, frame relay, or ATM, depending on the mix of applications and their performance requirements in terms of such metrics as reliability, availability, and latency. Sometimes it is necessary for the infrastructure to incorporate all three protocols because each is optimized to handle specific types of traffic. Of course, budgetary considerations also play a role in selecting the most appropriate protocol or mix of protocols for the network infrastructure.

Regardless of the infrastructure protocols used, the ability to assign a QoS to each type of traffic ensures the optimal performance of all the applications on the network. This also helps to contain bandwidth and equipment costs, which has the added advantage of making the enterprise network easier to manage and administer. It also makes the network easier to scale without necessarily having to add network equipment and aggregate bandwidth. On the flip side, however, the implementation of QoS mechanisims entail management challenges.

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