dracht.io is an application framework that is designed to let node.js developers easily integrate Voice-over-IP (VoIP) features into their applications using familiar middleware patterns.
The dracht.io architecture consists of the following components:
- drachtio-server - A high-performance, resilient SIP user agent that can be controlled by one or more client applications over a TCP network connection. The drachtio-server is written in C++ and is based on the open source sofia sip stack that is used in Freeswitch
- drachtio-client - Low-level javascript library that provides abstraction for SIP request and response processing.
- drachtio-connect - Higher-level framework designed to offer familiar middleware patterns to web application developers, enabling them to easily incorporate VoIP features into their applications.
drachtio-client is a low-level framework that is intended to be used in conjunction with drachtio-connect middleware. This document describes the drachtio-client feature set and API, but the reader is encouraged to review the drachtio-connect library as well. Generally speaking, a developer will interact with the dracht.io framework through the higher-level drachtio-connect middleware framework rather than directly through drachtio-client, although it is important to know how to create a client and to be familiar with the basic API and objects provided by this library.
dracht.io lets you build all sorts of SIP applications: SIP proxies, user agent clients and servers, back-to-back user agents, registrars, and more.
Here is an example showing how to create a simple SIP proxy server:
//require the drachtio client-side agent, and create an instance of it
var Agent = require('drachtio-client').Agent ;
var agent = new Agent(handler) ;
//connect to a drachtio server
agent.connect({
host: 'localhost',
port: 9022,
secret: 'cymru'
}) ;
//tell agent which messages we want to receive
agent.route('invite') ;
agent.route('bye') ;
//now handle incoming messages
function handler(req,res) {
if( req.msg.method === 'INVITE') {
req.proxy({
type: 'stateful',
destination: 'sip:1234@mydomain.com',
headers: {
'User-Agent': 'drachtio rockx!'
}
}, function(err, results){
if( err ) return console.error( 'Error attempting to proxy: ', err ) ;
console.log('results: ', JSON.stringify( results ) ) ;
}) ;
}
}