TCPSocket not found

I created a simple webserver that is streaming data to any client that connects to it through TCP. I tried to create a Titanium app and run it in the Titanium Mobile Web Previewer, but I keep getting the error: TypeError: Ti.Network.Socket is undefined at /index.html.

var hostname = "127.0.0.1";
var portNr = 1337;
 
var listeningSocket = Ti.Network.Socket.createTCP({
    host: hostname,
    port: portNr,
    connected: function(e) {
        Ti.API.error(JSON.stringify(e));
        Ti.API.error(JSON.stringify(e.socket));
        Ti.API.info('Socket opened!');
    },
    error: function(e) {
        Ti.API.error('Error (' + e.errorCode + '): ' + e.error);
    }
});
 
Ti.API.error("Socket created");
 
listeningSocket.listen();
Ti.API.error("Now listening on: "+listeningSocket.host+":"+listeningSocket.port);
 
 
var acceptedParams = {
    error : function(e) {
        // Do something with error
        Ti.API.error("ERROR");
    },
    timeout: 60000
};
 
listeningSocket.accept(acceptedParams);