Quality of Service (qos scripts) configuration [OpenWrt Wiki]

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

Name

Type

Required Default Description

enabled

boolean yes

Enable/Disable QoS

classgroup

string

yes?

(none)

no idea

overhead

boolean yes

decrease upload and download ratio to prevent link saturation

download

integer

yes

4096

kilobits/second

(only possible for tcp)

upload

integer

yes

512

kilobits/second

Rules

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.

Name

Type

Required Default Description

target

bucket

yes

(none)

The four defaults are:

Priority, Express, Normal

and

Bulk

proto

string

Packets matching this protocol belong to the bucket defined in target

srchost

string

(none)

Packets matching this source host(s) (single IP or in CIDR notation) belong to the bucket defined in target

dsthost

string

(none)

Packets matching this destination host(s) (single IP or in CIDR notation) belong to the bucket defined in target

ports

integer no

(none)

Packets matching this, belong to the bucket defined in target

srcports

integer no

(none)

Packets matching this, belong to the bucket defined in target

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http://wiki.openwrt.org/doc/uci/qos

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dstports

integer no

(none)

Packets matching this, belong to the bucket defined in target

portrange

integer no

(none)

Packets matching this, belong to the bucket defined in target

pktsize

integer no

(none)

Packets matching this, belong to the bucket defined in target

tcpflags

string

(none)

Packets matching this, belong to the bucket defined in target

mark

string

(none)

Packets matching this, belong to the bucket defined in target

layer7

string

(none)

Packets matching this, belong to the bucket defined in target

connbytes

int

(none)

Packets matching this, belong to the bucket defined in target

tos

string

(none)

Packets matching this, belong to the bucket defined in target

dscp

string

(none)

Packets matching this, belong to the bucket defined in target

direction

string

(none)

Packets matching this traffic direction (

out

) belong to the bucket defined in target

Classgroup

As we can have more then one interface, we can have more then one classgroup.

Name

Type

Required Default Description

classes

bucket names yes

(none)

Specifies the number of buckets and their names

default

bucket name

yes

(none)

Defines which bucket is considered default

Classes

Each Bucket has its own configuration.

Name

Type

Required Default Description

packetsize

integer yes

(none)

in bytes

packetdelay

integer yes

(none)

in ms

maxsize

integer yes

(none)

in bytes

avgrate

integer yes

(none)

unknown, value in %

limitrate

integer no

100

Defines to how much percent of the available bandwidth this class is capped to, value in %

maxsize

integer yes

(none)

in bytes

priority

integer yes

(none)

in %

Classes (For Advanced Users)

Below is unverified technical breakdown of each /etc/config/qos claass parameters. Source:

http://pastebin.com/YL55na2E

[http://pastebin.com/YL55na2E]

### Params:
#
# maxsize:
#       limits packet size in iptables rule
#
# avgrate: (note: sum(avgrates) ~ 100)
#       rt m1 = avgrate / sum (avgrate) * max_bandwidth
#       rt m2 = avgrate * max_bandwidth / 100
#       ls m1 = rt m1
#
# packetsize & packetdelay: (only works if avgrate is present)
#       rt d = max( packetdelay, 'time required for packetsize to transfer' ) (smaller ps ‐> smaller d)
#       ls d = rt d
#
# priority:
#       ls m2 = priority / sum (priority) * max_bandwidth
#
# limitrate:
#       ul rate = limitrate * max_bandwidth / 100

Quick start guide

1. Install the qosscripts package:

opkg install qos‐scripts

2. Basic configuration 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 set qos.wan.enabled=1
uci commit qos

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

/etc/init.d/qos start

4. Make script run at every boot up:

/etc/init.d/qos enable

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http://wiki.openwrt.org/doc/uci/qos

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Troubleshooting

(Last updated for: Barrier Breaker 14.07)

If your QoS doesn't seem to be working, it may be an error or typo in the config file is preventing it from loading properly.

Check enabled is set to 1 in /etc/config/qos(!)

Run iptablessave and check there are lines near the top prefixed with either A qos_Default or A qos_Default_ct, and featuring the –setxmark directive. Here's an
example:

‐A qos_Default ‐p tcp ‐m mark ‐‐mark 0x0/0xf0 ‐m tcp ‐‐sport 1024:65535 ‐‐dport 1024:65535 ‐j MARK ‐‐set‐xmark 0x44/0xff

The –setxmark is what flags the packet so it is picked up the traffic control subsystem.

Look at the generated traffic control qdisc settings by running:

tc qdisc

The default (ie noQoSapplied) values for any interface look like this:

qdisc fq_codel 0: dev eth0 root refcnt 2 limit 1024p flows 1024 quantum 300 target 5.0ms interval 100.0ms ecn

… Any interface with only a single qdisc line printed, showing the same settings as this line (this one is for dev eth0), indicates no QoS on that interface.

Network interfaces with QoS enabled will have multiple qdisc lines printed, each corresponding to a QoS class, etc.

If the printed qdisc settings don't seem to be correct, you can preview the tc commands generated from the OpenWRT /etc/config/qos by running:

/usr/lib/qos/generate.sh interface wan

(Replace 'wan' with the OpenWRT interface name you're debugging, as given in the /etc/config/qos file.)

This should print a series of insmod and tc commands used to set up the QoS subsystem. You can debug any errors caused by running these commands by running:

/usr/lib/qos/generate.sh interface wan | sh ‐x

(Note x option which tells sh to print each line as it is executed.)

The output of /usr/lib/qos/generate.sh is normally executed automatically as part of /etc/hotplug.d/iface/10qos.

txqueuelen

Recent versions of trunk uses

CoDel

[http://www.bufferbloat.net/projects/codel/wiki]

(pronounced: Coddle), so this should not be needed.

bufferbloat.net

[http://www.bufferbloat.net/projects/bloat/wiki/Linux_Tips#Reducetransmitqueuelength]

( Note: after i know about bufferbloat websearchd and many misguided users are asking about raising txqueuelen, or how to set it, and this was a recommended read
posted for them , and that just enabling QoS and setting up the rules i wanted didnt produce results, i thought of reduce txqueuelen from the default size of 1000 packets.
On most SOHO applications the upload speed is muchmuch lower than the interface speed (100M or 1G), and it's written that the def buffer is tailored for enterprise size
usage. I used values of 90 where[only] it was 1000 and it is wonderfully responsive and effective now, on a 256k connection. I also raised lenghts of 3 and 5 to 20 as i
imagined it might be hard to do any queuing/shaping on such ultra short buffers. Leave the 0s as 0. Btw, the 90 came by, that with 1500byte packet size and 256kbit
speed, it takes just half a sec to empty it. Well, i mistakenly took mtu as bits so it's 4 second really but i didnt have the courage for a drastically smaller than default
value, 90 already seem so smallish, and it works nicely anyway, awesome lack of latency, jitter and packetloss on the other machine, according to

http://pingtest.net

[http://pingtest.net]

, before of this there was no difference between mine and that. Note that this time doesnt correspond to ping values. The point is to allow builtin TCP

congestion control to work to reduce "spamming", set speeds as it was envisioned, and keep things leveled out rather than fluctuating widely. While this doesnt directly
effects QoSing itself, it is extremely beneficial, even essential, to the results usually expected from employing it. It sets a foundation, a healthy network environment
over which QoS to function.

First we list the stuff with

ifconfig

. Then apply for example

ifconfig eth0 txqueuelen 90

and

ifconfig pppoe‐wan txqueuelen 20

etc accordingly. Finally an

uci commit
/etc/init.d/network reload

might be needed, i did a network restart too after this.)

Types and Groups

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 TCPACKs 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 connectiontracked classification. Reclassify can override the traffic class per packet, without altering the connection tracking

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mark. Default is a fallback 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).