查询 DHT 服务器

I'm trying to make a simple simple example to test queries to the servers, but I don't get a response from the server in any form...

小例子:

$socket = fsockopen("udp://router.bittorrent.com", 6881, $errno, $errstr, 3);
fwrite($socket, 'p'); $Head = fread($socket, 4);
$CheckStatus = socket_get_status($socket);      
if($CheckStatus["unread_bytes"] == 0)
{
    return 0;
}   
$do = 1;
while($do)
{
    $str = fread($socket,1);
    $stats .= $str;
    $status = socket_get_status($socket);
    if($status["unread_bytes"] == 0)
    {
        $do = 0;
    }
}
fclose($socket);

关于 DHT 服务器查询的信息在这里:http://www.bittorrent.org/beps/bep_0005.html#dht-queries