ntain a level of service level agreement (SLA) with customer. To classify customer traffic, we use information in protocol data unit (PDU) at some layer. Once customer traffic is classified, it must be marked for differentiated services using protocol like 802.1P, precedence or IP differentiated services etc (Ravi Tomar, Hitesh Kumar, Ankur Dumka, Abhineet Anand, (2015); Derrick D'souza, Krishna Prabhu Sundharan, Savithru Lokanath, Vivek Mittal et.al,(2016)). Traffic in QoS is classified at access port and differentiated at network port. Using packet classification, you can partition network traffic into multiple priority levels or class of services. Committed Access Rate (CAR) is used for rate-limiting. Generic Traffic Shaper (GTS), Distributed Traffic Shaper (DTS) and Frame Relay Traffic Shaper (FRTS) are used for traffic shaper (Chui B., Yang Z.& Ding W., (2004); Kannan Govindarajan, Kong Chee Meng, Hong Ong,(2014); Egilmez A. T. H.E., Civanlar S., (2012)). Quality of services is of two types: Differentiated services (Diffserv) Integrated Services (Intserv) There are different methods to apply QoS IP Precedence Class of service termed as CoS is allowed by IP precedence for a packet. 3 bits are used to determine type of service as: Using 3 bits, you can 8 CoS, these bits define how to treat a packet and what will be its priority. Weighted fair queuing (WFQ) and weighted random early detection (WRED) uses queue method. Downloaded 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Quality of Service in SDN Technology Table 3. Relationship between different services Differentiated Services Integrated Services In differentiated service model a packet "class" can be In integrated service model Special QoS treatment marked directly in the packet. to the flow of router is determined by signalling. Differentiated service achieve better QoS Integrated service QoS is used for real-time traffic Diffserv model is RFC -2475 Intserv model is RFC-1633 Real time applications like remote video, Resources