When using htb, sometimes the htb quantum of class 10001 is big. Consider r2q change warning is encountered, and quantum is the computing basis for the htb subclass to use the parent class bandwidth. If this parameter is not set properly, unexpected results may occur.
Htb Manual suggests that the quantum value should be smaller than MTU. In this way, the best value of quantum is equal to MTU. If you do not set this parameter, the default value is quantum = rate/r2q, while the default value is r2q = 10, and the default value is MTU = 1500. That is to say, the default parameter is only applicable when rate = 15 kbps. When the actual bandwidth is different, you need to manually set the r2q parameter:
R2q = rate/MTU, the actual r2q is better than the calculated value, to ensure that the quantum> MTU.
Note: MTU viewing Method
Use netstat-I to view MTU values
[Root @ asterisk ~] # Netstat-I
Kernel interface table
Iface MTU met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR flg
Eth0 1500 0 60041 0 0 0 48841 0 0 0 bmru
Lo 16436 0 63 0 0 63 0 0 0 LRU