Systems and Network Infrastructure Integration

8Quality of Service and High Availability

“Quality is never accidental; it is always the result of intelligent effort.”

John Ruskin

– Understanding the concept of QoS and its objectives, as well as its usefulness for current IT infrastructures.

– Understanding the basic principles of QoS in networks (needs, structure, configuration options).

– Learning how to use data flow classification, improved enqueuing, and advanced load management techniques.

– Differentiating between QoS protocols or standards in the link and network layers.

– Understanding high availability mechanisms, in this case redundancy and backup.

– Describing the objectives and main protocols of level 2 and 3 redundancies.

– Understanding the general functioning of load balancing and data replication.

8.1. Introduction

These days, IT infrastructures offer more and more diverse services and serve as a framework for a wide range of applications. This varied offer must be accompanied by a service quality of assurance in order to ensure end-user satisfaction.

In reality, and in a context of convergence, services with different characteristics and different requirements must be provided by a single infrastructure that must ensure their proper functioning consistent with the levels of service required, or SLA (Service Level Agreement). Therefore, any plan to set up a network infrastructure must include and address the service quality aspect.

In the same vein, an effort to achieve high availability of the various ...