Network.js

A JavaScript library, entirely written in ES6, to measure various aspects of a connection. It can accurately estimate a bandwidth/latency between a client (using a web browser) and a server (running a specific script).

Installation

User Bower or download a ZIP file:

bower install network-js

<script src="bower_components/network-js/dist/network.min.js"></script>

How to use

// Create a new Network instance by providing an optional object.
var settings = {
    // The settings list is available below.
};
 
var net = new Network(settings);
 
// Listen for the "end" event which provides the calculated latencies.
net.latency.on('end', function(averageLatency, allLatencies) {
    // "allLatencies" is an array containing the five calculated latencies in
    // milliseconds. They're used to determine an average latency.
    console.log('end', averageLatency, allLatencies);
});
 
// Once all the configuration is done, start the requests for this module.
net.latency.start();
 
// It is possible to chain functions for all the modules, here's an example with the
// upload module.
net.upload
     .on('start', function(dataSize) {
         console.log('start', dataSize);
     })
     .on('progress', function(averageSpeed, instantSpeed) {
         // Every bandwidth measure are in Mega BYTES per second!
         console.log('progress', averageSpeed, instantSpeed);
     })
     .on('restart', function(dataSize) {
         // The restart event is triggered when the module didn't have time
         // (according to the `delay` option) to take all the measures. A new
         // request will start with data size increased by the multiplier value.
         console.log('restart', dataSize);
     })
     .on('end', function(averageSpeed, allInstantSpeeds) {
         console.log('end', averageSpeed, allInstantSpeeds);
     })
     .start();
 
// You can also cancel a request (except for the "latency" module).
net.upload.abort();
 
net.download
     .on('start', function(dataSize) {
         console.log('start', dataSize);
     })
     .on('progress', function(averageSpeed, instantSpeed) {
         console.log('progress', averageSpeed, instantSpeed);
     })
     .on('restart', function(dataSize) {
         console.log('restart', dataSize);
     })
     .on('end', function(averageSpeed, allInstantSpeeds) {
         console.log('end', averageSpeed, allInstantSpeeds);
     })
     .start();
 
net.download.abort();

Settings

The available settings with their default values:

{
    latency: {
        // Where is located your `network.php` file.
        endpoint: './network.php',
        // How many measures should be returned.
        measures: 5,
        // How much attempts to get a valid value should be done for each measure.
        attempts: 3
    },
 
    upload: {
        // Where is located your `network.php` file.
        endpoint: './network.php',
        // The delay while you want to take measures.
        delay: 8000,
 
        data: {
            // The amount of data to initially use.
            size: 2 * 1024 * 1024, // 2 MB
 
            // If the measure period can't reach the delay defined in the settings,
            // the data amount is multiplied by the following value.
            multiplier: 2
        }
    },
 
    download: {
        // Where is located your `network.php` file.
        endpoint: './network.php',
        // The delay while you want to take measures.
        delay: 8000,
 
        data: {
            // The amount of data to initially use.
            size: 10 * 1024 * 1024, // 10 MB
 
            // If the measure period can't reach the delay defined in the settings,
            // the data amount is multiplied by the following value.
            multiplier: 2
        }
    }
}

Here is an example usage:

var net = new Network({
    // If you define a value at the top level of the object,
    // it will be applied to every module.
    endpoint: './my-new-endpoint/',
 
    download: {
        data: {
            multiplier: 2.5
        }
    }
});

You can also redefine settings whenever you want:

// The `settings()` method takes an object in parameter.
net.settings({
    endpoint: './my-second-new-endpoint'
});
 
// Without any parameters, it will return the current settings.
console.log(net.settings()); // Prints the current settings in the console.
 
// Each module has a `settings()` method that works the same way.
net.latency.settings({
    measures: 10
});
console.log(net.latency.settings());

Compatibility

Network.js is based on two browser features: Resource Timing and XMLHttpRequest (v2). While the first one can be polyfilled, the second one is a requirement.

Thus, Network.js should be compatible with:

Browser	Partial support (polyfill)	Native support
IE 10+		✔
Firefox 35+		✔
Chrome 29+		✔
Opera 15+		✔
Android Browser 4.4+		✔
Safari 5+	✔
iOS Safari 5.1+	✔
Firefox 12+	✔
Opera 12.1+	✔
Android Browser 3+	✔

Latency measures can be very far from reality if the browser doesn't support Resource Timing and uses the provided polyfill. You can determine if the browser uses the latter:

if (Network.supportsResourceTiming) {
    // Resource Timing is available.
} else {
    // The polyfill will be used, expect some weird latency measures.
}

Caveats

• Chrome cannot upload a ~128 MB file, which will mainly affect fiber users.

Compilation

To compile the project, install the latest version of Node and run these commands inside a terminal:

git clone https://github.com/nesk/network.js.git
cd network.js
npm install
npm run build

There's also a watch script which compiles the project whenever a file is changed:

npm run watch

To check if the project passes all the tests, run:

npm test

Contribution

Read the CONTRIBUTING file.

License

This project is licensed under the MIT license, check TLDRLegal for details.