Looking for help using tc HTB to manage limited bandwidth shared connection.

shortonbandwidth · 03-21-2015, 01:03 PM

Hi all,

I am using tc with HTB to manage a limited bandwidth connection (2255kbps) with high latency (600ms~700ms).

I would like to split the bandwidth into two segments, one is 256kbps and the other is 1999kbps.

My current tc script looks like this:

Code:

tc qdisc add dev eth1 root handle 1: htb default 20
tc class add dev eth1 parent 1: classid 1:1 htb rate 2255kbps
tc class add dev eth1 parent 1:2 classid 1:10 htb rate 256kbit ceil 256kbit prio 1 mtu 1500
tc class add dev eth1 parent 1:2 classid 1:20 htb rate 1999bit ceil 2255kbit prio 0 mtu 1500
tc filter add dev eth1 parent 1:0 protocol ip prio 1 handle 80 fw flowid 1:10

I may be missing something but as I currently understand it the script above would create the two classes one 256kbps and the other 1999kbps with a ceiling of 2255kbps. I use iptables to tag the traffic I am interested in putting in the 256kbps bucket otherwise the default is the 1999kbps 1:20 htb class.

My problem is that when I apply this, my bandwidth is a mess it exceeds 2255kpbs and goes as high as 3000kbps. Where am I screwing this up? Any assistance would be greatly appreciated.

shortonbandwidth · 03-21-2015, 03:45 PM

I figured out part of my problem... typos...kbit not kbps and 1999kbit

Code:

tc qdisc add dev eth1 root handle 1: htb default 20
tc class add dev eth1 parent 1: classid 1:1 htb rate 2255kbit
tc class add dev eth1 parent 1:2 classid 1:10 htb rate 256kbit ceil 256kbit prio 1 mtu 1500
tc class add dev eth1 parent 1:2 classid 1:20 htb rate 1999kbit ceil 2255kbit prio 0 mtu 1500
tc filter add dev eth1 parent 1:0 protocol ip prio 1 handle 80 fw flowid 1:10

I am now getting the throughput I expect but I still feel like I am missing something.