sitespeedioSimulate slow network connections on Linux and Mac OS X
Inspired by tylertreat/Comcast, the connectivity setting in the WPTAgent and sltc.
Throttle uses pfctl on Mac and tc on Linux to simulate different network speeds. On Linux you also need ip for Throttle to work (install using sudo apt-get install -y net-tools).
You can set the download/upload speed and/or RTT. Upload/download is in kbit/s and RTT in ms.
Use with latest NodeJS LTS.
Install
npm install @sitespeed.io/throttle -gOn OSX, add these lines to /etc/pf.conf if they don't exist, to prevent the pfctl: Syntax error in config file: pf rules not loaded error when you try to run throttle
pf_enable="YES"
pflog_enable="YES"On Linux you need to make sure ip and route is installed (install using sudo apt-get install -y net-tools).
Start simulate a slower network connection
Here is an example for running with 3G connectivity. Remember: Throttle will use sudo so your user will need sudo rights.
throttle --up 330 --down 780 --rtt 200Pre made profiles
To make it easier we have pre made profiles, check them out by throttle --help:
--profile Premade profiles, set to one of the following
3g: up:768 down:1600 rtt:150
3gfast: up:768 down:1600 rtt:75
3gslow: up:400 down:400 rtt:200
2g: up:256 down:280 rtt:400
cable: up:1000 down:5000 rtt:14
dsl: up:384 down:1500 rtt:14
3gem: up:400 down:400 rtt:200
4g: up:9000 down:9000 rtt:85
lte: up:12000 down:12000 rtt:35
edge: up:200 down:240 rtt:35
dial: up:30 down:49 rtt:60
fois: up:5000 down:20000 rtt:2You can start throttle with one of the premade profiles:
throttle --profile 3gslowor even simpler
throttle 3gslowAdd packet loss
By default there's no packet loss. That is by design: If you want to use Throttle and have the same network speed, packet loss is no good. However if you want to simalate a really crappy network you probably want to add packet loss. You do that with the --packetLoss option. You set the packet loss in percent.
throttle --profile 3gslow --packetLoss 5Use a configuration file
You can also use a configuration file with your settings. Use --config to map your config file to throttle.
config.json
{
"up": 330 ,
"down": 200,
"rtt": 1000
}And then run:
throttle --config config.jsonStop simulate the network
Stopping is as easy as giving the parameter stop to throttle.
throttle --stopor
throttle stopAdd delay on your localhost
This is useful if you test a local web server or run WebPageReplay and want to add some latency to your tests.
throttle --rtt 200 --localhostStop adding delay on localhost
throttle --stop --localhostUse directly in NodeJS
import throttle from '@sitespeed.io/throttle'
// Returns a promise
throttle.start({up: 360, down: 780, rtt: 200}).then(() => ...or
import throttle from '@sitespeed.io/throttle'
// Returns a promise
const options = {up: 360, down: 780, rtt: 200};
await throttle.start(options);
// Do your thing and then stop
await throttle.stop();
Log all commands
You can log all the commands that sets up the throttling by setting LOG_THROTTLE=true.
LOG_THROTTLE=true throttle 3gslowor
throttle 3gslow --logRun in Docker (on Linux)
Make sure to run sudo modprobe ifb numifbs=1 before you start the container.
And then when you actually start your Docker container, give it the right privileges with --cap-add=NET_ADMIN.