Quality‐of‐Service Routing

Quality of service (QoS) is a parameter for standardizing the performance of a network in terms of the assurance and level of the services it offers. This chapter presents different sets of QoS parameters used by various organizations or in different literature sources in order to illustrate QoS measures. The International Engineering Task Force (IETF) has defined two models for implementation of QoS, differentiated services and integrated services. This chapter presents an overview of some of the QoS‐based path selection algorithms, such as the shortest widest path (SWP), and utilization‐based algorithms. In a QoS unicast routing, the data has to be sent from the source to only one destination through the feasible path that satisfies the QoS constraints. A QoS unicast routing protocol is broadly classified on the basis of the routing metrics into two categories: link‐constrained routing and link optimization routing. QoS multicast routing protocols are required to provide a path from a source to many destinations under constrained parameters as defined in the service level agreement (SLA).