Broadcast of udp module for ios not working

Has anyone succeeded to successfully broadcast a message using the UDP module in ios? I try to use the module to broadcast a message over u UDP socket, but this message is never sent. When I try the same with a specific address (a unicast), the message does get received. Is this a well-known issue with the module or am I doing something wrong?

The code I used for broadcasting a message is the same as in the example of the module:

var UDP = require('ti.udp');
 
socket = UDP.createSocket();
socket.start({port:4446});
 
socket.sendString({
        data: 'Hello, UDP!'
    });