A primer on QoS Routing in Multiservice IP Networks

QoS (Quality of Service) can be considered in any layer: •The user is mostly interested in application layer QoS•Each layer impacts on applicative QoS, by specific mechanisms•This presentation focuses on network level QoS, and more specifically on the impact of routing on delivered Network level QoS.Network level QoS does not necessarily apply to the same traffic flows that application level QoS or even Transport level QoS. Indeed, many procedures are used to support application traffic in the network:•Encapsulation of application data•Tunnelling of application data in specific channels•Aggregation of several application level flows into a single network level flow… .These procedures may obviously have a significant impact on the QoS delivered to the application.