Simulate slow network connections on Linux and Mac OS X
Throttle uses pfctl on Mac and tc on Linux to simulate different network speeds.
You can set the download/upload speed and RTT. Upload/download is in kbit/s and RTT in ms.
This is an early release, so please help us find potential bugs.
npm install @sitespeed.io/throttle -g
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 200
Pre 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:32 down:35 rtt:650 cable: up:1000 down:5000 rtt:14
You can start throttle with one of the premade profiles:
throttle --profile 3gslow
Stop simulate the network
Stopping is as easy as giving the parameter stop to throttle.
Add delay on your localhost (Linux only at the moment)
This is useful if you run WebPageReplay and want to add som latency to your tests.
throttle --rtt 200 --localhost
Stop adding delay on localhost (Linux only)
throttle --stop --localhost
Use directly in NodeJS
const throttle = ;// Returns a promisethrottlestartup: 360 down: 780 rtt: 200
Run 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