Toward A Reliable Network Design: A QoS Mapping Framework

No doubt that the information technology field is filled with various qualitative and quantitative concepts that are used to describe the desired performance for the network user or designer. The most common performance indicator concept is the reliability concept. Based on analyzing this concept in an IP network environment, the reliability concept is further expressed by the quality of service (QoS). Any regular network user definitely cares about the reliability of the services he perceives. This reliability in fact depends on the reliability of the underlying network. Therefore, the upper layer subjective requirements need to be transparently translated into lower layer objective ones. This paper presents a systematic framework for mapping the lower-layer network QoS performance parameter embodied by the packet loss rate into the upper-layer application QoS in an objective quantifiable way. In fact, currently with the advanced highspeed networks, the focus of the IP network performance is shifting from scalability, throughput and utilization benchmarks to guaranteeing loss bounds for different applications and users. Thus, this mapping will surely allow better and reliable system design and understanding of the technical network parameters from the application´s perspective of the service level agreement (SLA).