bps (12/4). For those nodes belonging to the contended group, no bandwidth reservation is applied for everyone. In other words, all of them have to contend the allocated bandwidth of this group. An SDN controller software (Ryu) is run up during the simulation with its restful north-bound interface being opened. We execute a script file to insert flow rules to the OpenFlow switch through the restful interface. We use one flow table and seven per-port output queues to realize the QoS service/scenario described above. From the simulation result, we can see that all those nodes applied with bandwidth reservation obtain the expected and stable receiving throughput (in KB/sec), and those nodes belonging to the contended group still obtain unstable throughput. Thus by using SDN technology for implementation of QoS services with the SDN network the performance factor for the network will be increased as shown in Figure 8. Downloaded: 4/15/2022 9:44:49 AN Nova Southeastern University IP Address: : 137.52.76.2 Quality of Service in SDN Technology Figure 8. Service implementation results Guaranteed Local Area Network Internet Quota Meps SDN Controller Fairly- shared 1000 Moos 1000 Mess Contended Color Option Graph As mentioned at the beginning, manually changing network devices' setting on demand is error-prone and the response time to demands is usually too long to satisfy needs on time. These problems can be solved by developing an intelligent SDN controller APP. A network administrator just has to classify users and assign their allowed quantum of bandwidth usage on the APP in advance. This APP is able to automatically detect the target network flows and automatically configure the Open Flow switch to guarantee the bandwidth usage for each target flow. REFERENCES Cao, Zhang, Huang, Zhang, & Gu. (2009). The design, Implementation and performance analysis of transport-MPLS network. IEEE Journal, 46-49. Chui, B., Yang, Z., & Ding, W. (2004). A load balancing algorithm supporting QoS for traffic engineering in MPLS networks.