Date Added: Nov 2010
The Next Generation Network (NGN), is an IP network with Quality of Service (QoS) support. Realtime applications should receive a treatment good enough to fulfill their requirements as for user needs. In this scenario, given quality parameters (e.g., end-to-end delay and loss) are to be guaranteed for all the packets or a high percentage of them. Different levels of service can be supported in a scalable manner using the DiffServ Architecture. Many algorithms have been proposed for differentiating service classes in DiffServ architecture, but the more promising, also for an efficient resource exploitation, is the Proportional Differentiation Model (PDM), in which, the quality spacing between classes of traffic is proportional to given class differentiation parameters that network operator can specify.