By default IOS does not let you apply CBWFQ directly to a sub interface. I ran into this scenario and worked my way around it in a workbook lab (IE Workbook Vol 2 - Lab 15). I thought it was pretty cool and hopefully it helps someone else out..
One of the most common questions that CCIE candidates face when studying QOS MQC for the lab is “What is the difference between bandwidth percent and bandwidth remaining percent?”. Both are used in CBWFQ when implementing congestion management but what is the difference? The answer to this questions are the focus of this tutorial.