与websocket在本地工作但无法在服务器上连接聊天

I made a chat for a site hosted with o2switch, the chat work perfectly in local, but when hosted, impossible to connect it.

I tried to write the address by many possibility, launch the webserver on differents ports.

Here the way to launch server in php:

protected function execute(InputInterface $input, OutputInterface $output)
    {
        $server = IoServer::factory(
            new HttpServer(new WsServer(new Chat())),
            8083


         );
    $server->run();

}

Here the connection in JS:

var ws = new WebSocket('ws://www.namesite.com:8083');

Error message :

Firefox can't establish a connection to the server at ws://www.namesite.com:8083