 are allocated by dividing the traffic into multimedia conferencing, real time applications are small number of classes by the DiffServ architecture motivated by IntServ architecture (Ankur Dumka, (Dongli Zhang and Dan Ionescu, (2007)). Hardwari Lal Mandoria, Vibudh Fore, Kanchan Dumka, (2015)) It provide end-to-end QoS (Desire Oulai, Steven No end-to-end signalling Chamberland & Samved Pierre, (2009)) For establishing QoS, "resource reservation" and "admission control" is supported by IntServ. RSVP "Admission control" and "resource reservation" is not is used to signal explicitly the need for QoS of supported by DiffServ. an application traffic in end-to-end path through network (Jyoti Tewari, Ankur Dumka, Gulista Khan, (2012)). Policy based routing (PBR) and Committed Access Rate (CAR) used to set precedence based on extended access-list classification. Value of IP precedence numbers (3bits): 0 - routine 1 - priority 1 - immediate 2 - flash 3 - flash-override 4 - critical 5 - internet 6 - network Using these classes you can define network policies in term of congestion and bandwidth allocation for each class using policy map and extended access list. Policy Based Routing (PBR) It allow us to configure a defined policy for traffic flow by setting IP precedence. It also specify for certain traffic, such as priority traffic over high cost link. Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Quality of Service in SDN Technology PBR help us to perform following task: Classify traffic based on extended access-list. Access list then establish match criteria. (Access-list is used for policy with match route map and having match clause for specific routes to pass through) Set IP precedence bits, thus enable differentiated CoS Route packet to specific traffic engineered paths. Policy can be based on IP address, port number and protocol or size of packets. Committed Access Rate (CAR) It improved classification services and policing through rate limiting. Classification service of CA