Quality of Service

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You are here: Main Page/DD-WRT Docu (EN)/Quality of Service



Quality of Service (QoS) is a method to guarantee a bandwidth relationship between individual applications or protocols. This is very handy when you max out your connection so that you can allow for each application to have some bandwidth and so that no single application can take down the internet connection. This allows, for example, a full speed download via FTP without causing jittering on a VOIP chat. The FTP will slow down slightly as bandwidth is needed for the VOIP, provided VOIP was given greater priority.

If you would like to set hard coded bandwidth limits (Throttling), this can be done using the tc command


Initial Setup

  • Log into the Web Interface
  • Click on the Applications and Gaming Category
  • Click on the QoS sub category
  • Tick "Enabled" and save the settings
  • Set Port to WAN
  • Enter 85% of your Up and Down bandwidth in the boxes (eg: if you have a 1.5Mbit (1536kbps) cable modem with 256kbps upload, enter 218 for uplinkand 1306 for dwnlink)

This will enable Quality of Service and Cap your maximum connection speed to 85% of what your cable/dsl service is capable of providing. This decrease in speed is required to allow WonderShaper to prioritize your bandwidth.

Enabling Services

  • Choose the service you would like to prioritize or deprioitize and click add
  • Change the priority of the service and click save. Unconfigured services are always standard.

Prioritizing by IP Address

-If there is a specific ip address, enter xxx.xxx.xxx.xxx / 32 -If there is a range, enter it using netmask notation. The [Netmask Calculator http://www.csc.fi/english/funet/calc/laskin2.html] might be useful


  • easy htb/tc configurator or script generator
  • categorized all other ports not configured as bulk, not as standard like current config

this will surely slowing down any virus/worm trying to spread in the network. thus, will not slowing down the whole internet.

See these links: http://wl500g.info/showthread.php?t=2515


(NOTE This will NOT slow down the spread of viruses. QoS does not work that way. Viruses will spread at their normal rate, but you will not notice it on your internet connection since the viruses will have a lower priority. QoS works by slowing down lower priority traffic instantly, and then resuming it to full speed instantly as higher priority traffic uses bandwidth. What you are suggesting will simply allow you to spread viruses without noticing it, allowing you to live longer without realizing you are infected. In order to slow the spread of viruses you would need to THROTTLE all undefined ports. Throttling is limiting to a specific rate constantly and is not dynamic as QoS is. EX, limit all undefined traffic to 1k/s)

other QoS improvement

 * http://frottle.sourceforge.net/
 * http://patraswireless.net/software.html

External Links

[Netmask Calculator http://www.csc.fi/english/funet/calc/laskin2.html]

You are here: Main Page/DD-WRT Docu (EN)/Quality of Service