Easy to use WebRTC data channels and media transport

• Easy to use
• Lightweight
  • No need to deal with WebRTC stack!
  • Small binary sizes
• Has Prebuilt binaries (Linux,Windows,ARM)
• Type infos for Typescript

"libdatachannel is a standalone implementation of WebRTC Data Channels, WebRTC Media Transport, and WebSockets in C++17 with C bindings for POSIX platforms (including GNU/Linux, Android, and Apple macOS) and Microsoft Windows. It enables direct connectivity between native applications and web browsers without the pain of importing the entire WebRTC stack. "

This project is NodeJS bindings for libdatachannel library.

Please check libdatachannel for Compatibility & WebRTC details.

Example Usage

const nodeDataChannel = require('node-datachannel');

// Log Level
nodeDataChannel.initLogger("Debug");

let dc1 = null;
let dc2 = null;

let peer1 = new nodeDataChannel.PeerConnection("Peer1", { iceServers: ["stun:stun.l.google.com:19302"] });

// Set Callbacks
peer1.onLocalDescription((sdp, type) => {
    console.log("Peer1 SDP:", sdp, " Type:", type);
    peer2.setRemoteDescription(sdp, type);
});
peer1.onLocalCandidate((candidate, mid) => {
    console.log("Peer1 Candidate:", candidate);
    peer2.addRemoteCandidate(candidate, mid);
});

let peer2 = new nodeDataChannel.PeerConnection("Peer2", { iceServers: ["stun:stun.l.google.com:19302"] });

// Set Callbacks
peer2.onLocalDescription((sdp, type) => {
    console.log("Peer2 SDP:", sdp, " Type:", type);
    peer1.setRemoteDescription(sdp, type);
});
peer2.onLocalCandidate((candidate, mid) => {
    console.log("Peer2 Candidate:", candidate);
    peer1.addRemoteCandidate(candidate, mid);
});
peer2.onDataChannel((dc) => {
    console.log("Peer2 Got DataChannel: ", dc.getLabel());
    dc2 = dc;
    dc2.onMessage((msg) => {
        console.log('Peer2 Received Msg:', msg);
    });
    dc2.sendMessage("Hello From Peer2");
});

dc1 = peer1.createDataChannel("test");

dc1.onOpen(() => {
    dc1.sendMessage("Hello from Peer1");
});

dc1.onMessage((msg) => {
    console.log('Peer1 Received Msg:', msg);
});

setTimeout(() => {
    dc1.close();
    dc2.close();
    peer1.close();
    peer2.close();
    nodeDataChannel.cleanup();
}, 10 * 1000);

Please check examples/media folder for media usage example

Install

Prebuilt binaries are available (Node Version >= 10);

• Windows (x86, x64)
• Linux (x64, armv7, arm64)
• Mac

> npm install node-datachannel --save

API

PeerConnection Class

Constructor

let pc = new PeerConnection(peerName[,options])

• peerName <string> Peer name to use for logs etc..
• options <Object> WebRTC Config Options

export interface RtcConfig {
    iceServers: (string | IceServer)[];
    proxyServer?: ProxyServer;
    enableIceTcp?: boolean;
    portRangeBegin?: number;
    portRangeEnd?: number;
    maxMessageSize?: number;
    iceTransportPolicy?: TransportPolicy;
}

export const enum RelayType {
    TurnUdp = 'TurnUdp',
    TurnTcp = 'TurnTcp',
    TurnTls = 'TurnTls'
}

export interface IceServer {
    hostname: string;
    port: number;
    username?: string;
    password?: string;
    relayType?: RelayType;
}

export type TransportPolicy = 'all' | 'relay';

"iceServers" option is an array of stun/turn server urls
Examples;
STUN Server Example          : stun:stun.l.google.com:19302
TURN Server Example          : turn:USERNAME:PASSWORD@TURN_IP_OR_ADDRESS:PORT
TURN Server Example (TCP)    : turn:USERNAME:PASSWORD@TURN_IP_OR_ADDRESS:PORT?transport=tcp
TURN Server Example (TLS)    : turns:USERNAME:PASSWORD@TURN_IP_OR_ADDRESS:PORT

close: () => void

Close Peer Connection

setRemoteDescription: (sdp: string, type: DescriptionType) => void

Set Remote Description

export const enum DescriptionType {
    Unspec = 'Unspec',
    Offer = 'Offer',
    Answer = 'Answer'
}

addRemoteCandidate: (candidate: string, mid: string) => void

Add remote candidate info

createDataChannel: (label: string, config?: DataChannelInitConfig) => DataChannel

Create new data-channel

• label <string> Data channel name
• config <Object> Data channel options

export interface DataChannelInitConfig {
    protocol?: string;
    negotiated?: boolean;
    id?: number;
    ordered?: boolean;
    maxPacketLifeTime?: number;
    maxRetransmits?: number;

    // Deprecated, use ordered, maxPacketLifeTime, and maxRetransmits
    reliability?: {
        type?: ReliabilityType;
        unordered?: boolean;
        rexmit?: number;
    }
}

export const enum ReliabilityType {
    Reliable = 0, Rexmit = 1, Timed = 2
}

state: () => string

Get current state

signalingState: () => string

Get current signaling state

gatheringState: () => string

Get current gathering state

onLocalDescription: (cb: (sdp: string, type: DescriptionType) => void) => void

Local Description Callback

export const enum DescriptionType {
    Unspec = 'Unspec',
    Offer = 'Offer',
    Answer = 'Answer'
}

onLocalCandidate: (cb: (candidate: string, mid: string) => void) => void

Local Candidate Callback

onStateChange: (cb: (state: string) => void) => void

State Change Callback

onSignalingStateChange: (state: (sdp: string) => void) => void

Signaling State Change Callback

onGatheringStateChange: (state: (sdp: string) => void) => void

Gathering State Change Callback

onDataChannel: (cb: (dc: DataChannel) => void) => void

New Data Channel Callback

bytesSent: () => number

Get bytes sent stat

bytesReceived: () => number

Get bytes received stat

rtt: () => number

Get rtt stat

getSelectedCandidatePair: () => { local: SelectedCandidateInfo, remote: SelectedCandidateInfo }

Get info about selected candidate pair

export interface SelectedCandidateInfo {
    address: string;
    port: number;
    type: string;
    transportType: string;
}

DataChannel Class

You can create a new Datachannel instance by calling PeerConnection.createDataChannel function.

close: () => void

Close data channel

getLabel: () => string

Get label of data-channel

sendMessage: (msg: string) => boolean

Send Message as string

sendMessageBinary: (buffer: Buffer) => boolean

Send Message as binary

isOpen: () => boolean

Query data-channel

bufferedAmount: () => number

Get current buffered amount level

maxMessageSize: () => number

Get max message size of the data-channel, that could be sent

setBufferedAmountLowThreshold: (newSize: number) => void

Set buffer level of the onBufferedAmountLow callback

onOpen: (cb: () => void) => void

Open callback

onClosed: (cb: () => void) => void

Closed callback

onError: (cb: (err: string) => void) => void

Error callback

onBufferedAmountLow: (cb: () => void) => void

Buffer level low callback

onMessage: (cb: (msg: string | Buffer) => void) => void

New Message callback

Build

Requirements

• cmake >= V3.14
• libdatachannel dependencies

Building from source

> git clone https://github.com/murat-dogan/node-datachannel.git
> cd node-datachannel
> npm i

Other Options

> npm run install -- -DUSE_GNUTLS=1  # Use GnuTLS instead of OpenSSL (Default False)
> npm run install -- -DUSE_NICE=1    # Use libnice instead of libjuice (Default False)

Test

> npm run test                  # Unit tests
> node test/connectivity.js     # Connectivity

More Examples

Check examples folder

Thanks

Thanks to Streamr for supporting this project by being a Sponsor!