Measuring Quality of Service in Packet Networks

Authors

Abstract

Several approaches have been proposed to empower com-munication systems with quality of service (QoS) capabili-ties. In general, their main goal is to coherently support the end-to-end performance needs of applications, based on the establishment of, and agreement on, a set of concepts, poli-cies and mechanisms. Regardless of the used approach, an important challenge associated with quality of service provi-sion is the development of an efficient and flexible way to monitor QoS.
The existence of an effective metric to quantify the QoS of-fered to classes or flows of data, and to assess the perform-ance of communication systems, would facilitate the imple-mentation of a QoS monitor. Such a QoS metric should be able to produce comparable measures, independently of the nature and scope of the objects to quantify, that is, should turn possible uniform QoS measures. Nevertheless, the main difficulty related to the development of such metric steams exactly from the disparate nature and scope of the things to measure (typically, throughput, transit delay or loss).
This paper discusses the above mentioned difficulties and proposes a QoS metric intended to support QoS measure-ments on packet switching networks. In our opinion, the pro-posed metric will facilitate the development of an effective and truly integrated QoS management system, which is fun-damental to construct QoS-capable communication systems able to efficiently deal with the increasing variety of applica-tions.
This paper also presents the main challenges found during the first approach to the QoS metric implementation. The intention was to test the metric basic concepts, to assess its feasibility, and to measure its associated overhead. The results of these overhead tests are also presented.

Conference

2nd Conference on Telecommunications, Instituto de Telecomunicações (Portugal), Sesimbra, Portugal, 15-16 April, 1999, April 1999