IP, Ethernet and MPLS Networks: Resource and Fault Management

Chapter 2

Characterizing Quality of Service

2.1. Quality of service functions

Quality of service is the overall effect produced by the performance of a service, which determines the degree of user satisfaction. The term “quality of service” generally does not have a clear definition, and is often used too vaguely. Another difficulty lies in the interrelation of functions related to the application of a service with the different criteria used to evaluate quality of service.

The functions associated with quality of service pertain to service management, the quality of the connection, service billing, and network management.

Service management concerns the following aspects:

– the preparation of a Service Level Agreement (SLA) service contract;

– the provisioning, modification, and termination of the service;

– support and repairs.

The quality of the connection defines the criteria relating to the establishment and release of the connection, and to data transfer.

Network management, performed by the service provider, assists in providing the client with measurement reports regarding effective parameters for quality of service.

Quality of service functions and their associated criteria should be considered from four viewpoints:

– quality of service corresponding to the needs expressed by the user;

– quality of service as offered by the provider;

– quality of service actually provided;

– quality of service as perceived by the user.

From the client’s point of view, quality of service ...