There are two implementations of Weighted Fair Queuing (WFQ) in IOS:
Distributed Weighted Fair Queuing (DWFQ)
All Cisco platforms covered in this book, except Cisco 12000, support platform-independent WFQ. DWFQ is available only on VIP interfaces on 7500 series routers when dCEF switching is enabled.
IOS has two implementations of platform-independent WFQ:
Flow-Based WFQ is similar to custom queuing in its effect on traffic streams, but rather than defining a static policy to sort the packets into the individual queues, the streams are sorted automatically. Flow-Based WFQ is a legacy congestion management feature in IOS and ...