IEEE Communications Surveys & Tutorials - third quarter 2008
Nelson L. S. da Fonseca · IEEE Communications Surveys & Tutorials · 2008
n the past decade, we have witnessed the evolution of IP networks from providing a single best-effort service to pro-viding multiple types of services with Quality-of-Service (QoS) guarantee, namely bounded packet delay and loss. Although the majority of current network traffic is still best-effort, emerging networked applications with different QoS con-straints (e.g., multimedia applications) are becoming more popular, and may soon contribute an appreciable share of total network traffic. In addition, users are demanding better QoS guarantees for their traffic, or QoS differentiation for their virtual private networks (VPNs). The Integrated Service (IntServ) framework is an attempt to achieve end-to-end per-flow QoS is, whereby bandwidth along the path is reserved for individual flows through RSVP. IntServ was unsuccessful in large-scale networks mainly due to scalability and heterogene-