UDP supplies minimized transmission delay by omitting the connection setup process, flow control, and retransmission. Meanwhile, more than 80 percent of the WAN resources are occupied by Tramsmission Control Protocol (TCP) traffic. As opposed to UDP's simplicity, TCP adopts a unique flow control mechanism with sliding windows. Hence, the quality of service (QoS) of real-time applications using UDP is affected by TCP traffic and its flow control mechanism whenever TCP and UDP share a bottleneck nodeIn other words, TCP is an internet/queue hog. TCP complains more (error checking/ordering/retransmission) so just like an individual that complains more and one that doesn't, the complainer causes more delay + problems but gets more of the pie/focus because of it.