This is a documentation for the UCI configuration file /etc/config/qos. It is used by the package qos-scripts only.

So far (2010) there are at least two other packages in the OpenWrt repositories regarding QoS/ToS: dsl-qos-queue and wshaper. They do not use this file. Please do not install multiple QoS-packages simultaneously! Simply de-install the old one, before installing a new one. dsl-qos-queue does factor in the ATM (Asynchronous Transfer Mode) overhead, which can be significant.

You can browse the scripts here: qos-scripts There is direct LuCI-support for qos-scripts called: luci-app-qos.

For help writing your own script please see Packet Scheduler.

As of r25641 qos-scripts dropped the use of IMQ (package iptables-mod-imq – Intermediate Queueing Device). Its successor is IFB (Intermediate Functional Block device), (requires package: kmod-ifb and the scheduler action act_connmark included).

A minimal QoS configuration usually consists of one interface section, of some rules allocating packets to at least two buckets and of the configuration of the buckets.

Each Interface can have its own buffer. The interface section declares global characteristics of the connection on which the specified interface is communicating. The following options are defined within this section:

config interface dsl
        option enabled      1
        option classgroup  "Default"
        option overhead     1
        option upload       512
        option download     4096

Each classify section defines one group of packets and which target (i.e. bucket) this group belongs to. All the packets share the bucket specified.

As we can have more then one interfaces, we can have more then one classgroups.

Each Bucket has its own configuration.

1. Install the qos-scripts package:

opkg install qos-scripts

2. Perform minimum configuration needed using UCI command line:

uci set qos.wan.upload=1000            # Upload speed in kBits/s
uci set qos.wan.download=16000         # Download speed in kBits/s
uci commit qos

3. Start it immediatly (look for error output and test):

/etc/init.d/qos start

4. Make script run at every boot up:

/etc/init.d/qos enable

The qos-scripts package didn't come with documentation and there has been some confusion about its features, among users. The information in this section comes straight from nbd (the developer), so it should come a long way to clearing some confusion on two major issues.

The biggest item of contention was which group setting gives better performance, Priority or Express. As it turns out, it depends on the application. Priority boosts low-bandwidth small frames, such as TCP-ACKs and DNS more than Express. Express is for prioritizing bigger frames, which would include stuff like VoIP (port 5060).

Another biggie was the exact meaning of each type. Types are necessary for connection tracking. By default, Classify is not run on a connection that had already been assigned a traffic class, so it is the initial connection-tracked classification. Reclassify can override the traffic class per packet, without altering the connection tracking mark. Default is a fall-back for everything that has not been marked by Classify/Reclassify. Rules get processed by type first (Classify gets processed first, then Reclassify and finally Default) and then based on the order in the configuration file (top to bottom).