 and associated with buffer utilization is a probability value. This value determines the probability that the incoming packets will be dropped by router. As current average buffer utilization increases, SO does probability that the incoming packet will be dropped. Weighted Random Early Detection (WRED) It works in same manner as RED; however it enables the distinction of packets with different marking like "in-profile", "out-of-profile" packets. Therefore, with WRED, a router can start to discard "out-of-profile" packets with greater probability than "in-profile" packets for a given average buffer utilization. Scheduling Scheduling is another QoS feature implementation scheme, which determines when to serve and forward a packet in a given queue, relative to other queues. It also determines how allocation underlying link's capacity amongst various queues that share that link. Common scheduling algorithms are: Strict priority Round robin and weighted/biased round robin Fair queuing and weighted fair queuing Downloaded: 4/15/2022 9:44:49 AM Nova Southeastern University IP Address: 137.52.76.29 Quality of Service in SDN Technology Strict priority scheduling queues are ordered with relative priority. Schedulers serve queues in order of priority. It is useful for traffic with low latency requirements. In round robin and weighted/biased round robin, there is no priority between queues; scheduler services a packet from each queue in sequence. Thus, each queue gets an equal amount of servicing time. In weighted/biased RR scheduler certain queue can be provided with higher servicing rate by allowing a queue to receive more frequent visits from the scheduler. In fair queuing and weighted fair queuing, each number of queues contended for resources are allocated service opportunity based on an assigned weight. Weight may be derived from bandwidth allocation to queue. It determines scheduling sequence needed to service a queue SO that it meets its long term bandwidth target. Shaping Shaping is used for rate limiting, improves