What is the difference between WFQ and CBWFQ?
Native Weighted Fair Queueing (WFQ) assigns a weight to each conversation, and then schedules the transmit time for each packet of the different flows. The weight is a function of the IP precedence of each flow, and the scheduling time depends on the packet size. WFQ was implemented for slow speed links (such as serial) to provide a fair treatment for each type of traffic. To do its job, WFQ classifies the traffic into different flows based on the associated Layer 3 and Layer 4 information (IP addresses, TCP ports, and so on). You do not need to define access-lists in order for this to work. Therefore, with WFQ, low bandwidth traffic has effective priority over high bandwidth traffic. The high bandwidth traffic shares the transmission media proportionally to assigned weights. However, WFQ is not scalable if the flow amount increases considerably, and it is not available on high-speed interfaces such as ATM interfaces. CBWFQ provides a solution to these limitations. CBWFQ assigns a weig