Chapter 8 - Technical Challenges

Abstract

QoS is defined as using Diffserv to create service differentiation therefore, most QoS publications focus on traffic management. Traffic management mechanisms include classification, marking, policing and remarking, shaping, queuing, and buffer management, and packet dispatching. The traffic management mechanisms can be used to create Diffserv Per Hop Behavior (PHB) at each network device, which will result in the creation of multiple traffic classes in the network. Traffic Engineering (TE) involves optimizing traffic distribution in one's network that can be done with a Diffserv-agnostic manner or a Diffserv-aware manner. Common TE can be done by tuning one's interdomain routing policy, or intradomain routing metrics, or using MPLS. Diffserv traffic management is good for creating some service differentiation when there is congestion, routing and TE can be used to reduce congestion or prevent congestion from happening. Content Delivery Network (CDN) can be used to move content closer to the end users, thus making the delay, delay variation, and packet loss ratio of a long network segment that is left behind by CDN irrelevant. The routing, TE, and CDN can be considered more effective for providing QoS than traffic management Traffic management only affects the performance of traffic at a specific link of a network device.