Easily multiply an AES67 Stream for load testing. SDP has to be adjusted accordingly

aes67-multiply.js

const dgram = require('dgram');
const process = require('process');
const sdp = require('./sdp');
let client = dgram.createSocket({ type: 'udp4', reuseAddr: true });


let clients = [];

if(!process.argv[2] || !(parseInt(process.argv[2]) > 0)){
	console.log('$ node multiply 12');
	process.exit();
}

for(var i = 0; i < parseInt(process.argv[2]); i++){
	let mcast = '239.69.'+(Math.floor(Math.random() * 256))+'.'+(Math.floor(Math.random() * 256));

	clients[i] = {
		mcast: mcast,
		dgram: dgram.createSocket('udp4')
	};

	clients[i].dgram.on('listening', function() {
		this.setMulticastInterface('192.168.1.100');
	});

	clients[i].dgram.bind();
	sdp.add(mcast);
}

client.on('listening', function() {
	client.setMulticastInterface('192.168.1.100');
	client.addMembership('239.69.161.174', '192.168.1.100');
});

client.on('message', function(buffer, remote) {
	for(var i = 0; i < clients.length; i++){
		clients[i].dgram.send(buffer, 5004, clients[i].mcast);
	}
});


setTimeout(function(){
	client.bind(5004);
}, 1000);

sdp.js

var dgram = require('dgram');
var socket = dgram.createSocket({ type: 'udp4', reuseAddr: true });

let ipAddress = '192.168.1.100';

var constructSDPMsg = function(multicastAddr, number){
	let hash = Math.floor(Math.random() * 65536);
	let id = Math.floor(Math.random() * 2*65536);
	let sapHeader = Buffer.alloc(8);
	let sapContentType = Buffer.from('application/sdp\0');
	let ip = ipAddress.split('.');

	//write version/options
	sapHeader.writeUInt8(0x20);

	//write hash
	sapHeader.writeUInt16LE(hash, 2);

	//write ip
	sapHeader.writeUInt8(parseInt(ip[0]), 4);
	sapHeader.writeUInt8(parseInt(ip[1]), 5);
	sapHeader.writeUInt8(parseInt(ip[2]), 6);
	sapHeader.writeUInt8(parseInt(ip[3]), 7);

	var sdpConfig = [
		'v=0',
		'o=- '+id+' '+id+' IN IP4 '+ipAddress,
		's= Worker #'+number,
		'c=IN IP4 '+multicastAddr+'/32',
		't=0 0',
		'm=audio 5004 RTP/AVP 97',
		'i=2 channels: Left, Right',
		'a=recvonly',
		'a=rtpmap:97 L24/48000/2',
		'a=ptime:1',
		'a=ts-refclk:ptp=IEEE1588-2008:00-1D-C1-FF-FE-51-D7-EB:0',
		'a=mediaclk:direct=2578788582',
		''
	];

	var sdpBody = Buffer.from(sdpConfig.join('\r\n'));

	return Buffer.concat([sapHeader, sapContentType, sdpBody]);
}

let broadcast = function(){
	for(let i = 0; i < sdps.length; i++){
		socket.send(sdps[i], 9875, '239.255.255.255', function(err){});
	}
}

exports.start = function(){
	socket.bind(9875, function(){
		socket.setMulticastInterface(ipAddress);
	});
}

let sdps = [];

exports.add = function(mcast){
	console.log(mcast);
	let sdpBuffer = constructSDPMsg(mcast, sdps.length + 1);
	sdps.push(sdpBuffer);
	socket.send(sdpBuffer, 9875, '239.255.255.255', function(err){});
}

process.on('SIGINT', function(code){
	for(let i = 0; i < sdps.length; i++){
		sdps[i].writeUInt8(0x24, 0);
		socket.send(sdps[i], 9875, '239.255.255.255', function(err){});
	}

	setTimeout(function(){
		process.exit();
	}, 100);
});

setInterval(broadcast, 5*1000);