21 thoughts on “Traffic shaping with OpenWRT”

1. Tom April 29, 2013 at 6:47 PM

   Thank you!

   Reply ↓
   1. Tom April 29, 2013 at 10:06 PM

      When running this script I’m receiving the following errors: “File exists” for insmod sch_ingress & cls_u32 ( I’m guessing those aren’t needed in the script then), “RTNETLINK answers: No such file or directory”, “RTNETLINK answers: Invalid argument”, “‘burst’ requires ‘rate'” & “Illegal ‘police'”. This is via the latest trunk image for my WNDR3700 with the ‘tc’ module installed.

      Any idea why this script isn’t functioning as intended?

      Reply ↓
      1. Thomas Elsen Post authorApril 29, 2013 at 11:59 PM

         You can ignore the warnings from insmod. You get these when the modules are already loaded.

         Regarding the other errors: I’ll install the latest trunk to test the script again and let you know.
         Best regards

         Reply ↓
         1. Tom April 30, 2013 at 2:51 PM

            Reflashing to Backfire 10.03.1 solved a lot of issues, apparently the ingress/egress queuing disciplines were not compiled in the trunk image’s kernel. I get no insmod errors now, however the lines “$TC qdisc del dev $DEV root” and “$TC qdisc del dev $DEV ingress” replied with RTNETLINK errors, and it also seems the ingress portion of this script is non-functional. Furthermore, under rc.local, the line should be “sh /etc/shape.sh” correct?

            Any idea why downlink shaping isn’t occurring?

            Reply ↓
            1. Tom April 30, 2013 at 3:13 PM

               Because VoIP uses the UDP protocol I changed “match ip tos from 0x88 0xff” to “match ip protocol 17 0xff” (/etc/protocals lists UDP as 17).

               Still no idea why downlink throttling is not occurring but uplink shaping is better than nothing.
            2. Thomas Elsen Post authorApril 30, 2013 at 3:46 PM

               Tom, the Siemens VOIP phones that I used are sending out SIP traffic with a TOS field with 0x88. That’s why I hard coded that value in my script. I don’t want to give priority to all UDP traffic on my network. Especially since I’m using OpenVPN to pull/push backups to/from servers on the internet. All that VPN traffic would be UDP as well.
            3. Thomas Elsen Post authorMay 3, 2013 at 9:42 AM

               I’ve added kmod-sched to the list of packages to install. That should fix the downlink throttling.

               Thanks for your feedback.

2. Pingback: Traffic shaper benchmark | Thomas Elsen Security Blog

3. Pieter-Bas June 29, 2013 at 3:57 PM

   Hi, thanks for the explanation. I’d like to do traffic shaping for exactly the same reason as you are.

   I’m connected by FTH and I have a synchrone bandwith. Can you just explain me the ratio settings. 1:10 or 1:20. Is this a ratio or what is it exactly?

   Then another question: with synchrone bandwith, can I use this script, or should I use something else? Since download shaping is important to me as well and in your script, download shaping is only policed using a tc filter containing a Token Bucket Filter.

   thanks in advance,
   Pieter-Bas

   Reply ↓
   1. Pieter-Bas June 29, 2013 at 4:07 PM

      Okay, I found the answer to my 2nd question:
      “You do NOT have the same level of control over download traffic, i.e. traffic arriving at your router from the Internet. Here, you can only drop packets but not rearrange them.
      The dropping of TCP packets, causes the sending site to reduce it’s transmission rate, the dropping of UDP packets however, will only help to keep the buffer empty.”

      Source: http://wiki.openwrt.org/doc/howto/packet.scheduler/packet.scheduler

      Reply ↓
4. Mario November 21, 2013 at 2:02 PM

   Hi, thanks for sharing.

   A stupid question: if I just want to limit bandwidth usage I would only have to set variables UPLINK and DOWNLINK accordingly, right?

   I have a dedicated router that broadcasts an open separate guest network that I want to cap at specific speed limits.

   Reply ↓
   1. Thomas Elsen Post authorNovember 21, 2013 at 3:09 PM

      Indeed, that’s correct.
      Best regards,
      Thomas

      Reply ↓
5. Mario November 21, 2013 at 3:23 PM

   Of course, I would use the generic script ‘The ultimate traffic confitioner’ that you’ve mentioned, since I don’t want to prioritize any specific application…

   Reply ↓
6. Denis Tunjic May 8, 2014 at 12:33 PM

   Hi i just added the script this way…

   vi /etc/init.d/shape.sh

   pasted your script….

   then saved it

   then i enabled start at boot by

   /etc/init.d/shape.sh enable

   is this right….

   also i get an error cant find device eth1

   im using 12.09 Attitude Adj

   with a tplink wdr4300

   and help with this would be great…

   will this script work where i am uploading with torrents and when i want to stream youtube or music that it will stop the buffering…???

   Thanx Heaps

   Denis

   Reply ↓
   1. Thomas Elsen Post authorMay 14, 2014 at 10:42 AM

      Hi Denis,

      First check what your external interface is. ‘ifconfig’ will list all the interfaces.

      If you have it, change all occurences of eth1 with your external interface in ‘/etc/init.d/shape.sh’.

      Best regards,
      Thomas

      Reply ↓
7. Hans Van Den Heuvel May 26, 2014 at 9:58 AM

   Hi I followed your guide , but when I started benchmarking nothing happened , when I tried to run the shape.sh file with terminal , terminal didnt found it .
   Can you help me pls

   Best regards,
   Hans

   Reply ↓
   1. Thomas Elsen Post authorMay 28, 2014 at 11:14 AM

      Are you sure that the file exists at the right place and has the right permissions (+x)?

      Thanks,
      Thomas

      Reply ↓
8. Ryan September 16, 2014 at 5:11 PM

   I’d like to tweak this to work differently depending on time of day, as my ISP offers unlimited bandwidth but throttles my connection for a four hour period every night to be able to offer this. Cron would work here, just running the script before and after the throttling period but it would work better if the script checked the time and then set the bandwidth figures based on that – How would you implement that?

   Reply ↓
   1. Thomas Elsen Post authorSeptember 17, 2014 at 9:49 AM

      I’d right 2 scripts with different values and run them using cron at the beginnning of each period. In my opinion, it’s easier to let cron handle the timing instead of the script.

      Reply ↓
9. shani November 14, 2014 at 9:33 PM

   I am having trouble starting shape.sh
   I am using openwrt KAMIKAZE (8.09.2, r18961)

   here is log:
   root@OpenWrt:/#
   root@OpenWrt:/# [J
   root@OpenWrt:/# /etc/shape.sh start[J
   insmod: cannot insert ‘/lib/modules/2.6.26.8/sch_htb.ko’: invalid parameters (17): Invalid argument
   insmod: cannot insert ‘/lib/modules/2.6.26.8/sch_sfq.ko’: invalid parameters (17): Invalid argument
   insmod: cannot insert ‘/lib/modules/2.6.26.8/sch_ingress.ko’: invalid parameters (17): Invalid argument
   insmod: Loading module failed: No such file or directory
   insmod: cannot insert ‘/lib/modules/2.6.26.8/cls_u32.ko’: invalid parameters (17): Invalid argument
   root@OpenWrt:/#

   Reply ↓
   1. Thomas Elsen Post authorNovember 15, 2014 at 2:02 PM

      Sorry, I haven’t tested it on KAMIKAZE. Can’t you upgrade?

      Reply ↓