Hi,
We''ve done a lots of tests on htb class to study behaviuor of delay.
We use this simple configuration:
tc qdisc add dev eth1 handle 1:0 root htb
tc class add dev eth1 parent 1:0 classid 1:1 htb rate 5000000 ceil 5000000 burst
30000 quantum 1600
tc class add dev eth1 parent 1:1 classid 1:10 htb prio 1 rate 1000000 ceil
1000000 quantum 1600
tc filter add dev eth1 parent 1:0 protocol ip prio 1 handle 1 fw classid 1:10
tc class add dev eth1 parent 1:1 classid 1:20 htb prio 1 rate 1500000 ceil
1500000 quantum 1600
tc filter add dev eth1 parent 1:0 protocol ip prio 1 handle 2 fw classid 1:20
tc class add dev eth1 parent 1:1 classid 1:100 htb prio 1 rate 2500000 ceil
2500000 quantum 1600
tc filter add dev eth1 parent 1:0 protocol ip prio 1 handle 10 fw classid 1:100
We create, with SmartBits device, 3 flows with this characteristics:
1° flows : lenght layer 2 64 - frame per second 1758 - bandwith total 900096
2° flows : lenght layer 2 1000 - frame per second 167 - bandwith total 1336000
3° flows : lenght layer 2 1500 - frame per second 187 - bandwith total 2244000
We are in conform traffic situation.
The results of tests show us that a lots of packet of 3° flow have a certain
delay (between 5ms - 100ms) but we can understand the reason.
If we change the frame per second of 3° flows to 120 , we notice that the 2°
flows have a certain delay too and nothing delay on the 3° flows!!!!!!
How it can be possible ?
How works qdisc pfifo_fast attached to each class ?
Where can be generate this delayed ?
We use htb version 3.7 on Kernel 2.4.20.
Thank, thank, thank !!!!
Ale&Enrick.
