Apns php错误“无法连接到Apns:110连接超时。”

我已经完成了php和objective c的apns代码 Apns code

和来自的安装证书 this link

用于向ios设备发送通知的沙盒和生产apns在我的服务器上运行良好。我将代码和相同的证书移动到客户端服务器,然后发送通知就不起作用了。

我调试了所有php代码,发现它停在这行代码上

private function _connectSSLSocket($development) {
    $ctx = stream_context_create();
    stream_context_set_option($ctx, 'ssl', 'local_cert', $this->apnsData[$development]['certificate']);
    $this->sslStreams[$development] = stream_socket_client($this->apnsData[$development]['ssl'], $error, $errorString, 100, (STREAM_CLIENT_CONNECT|STREAM_CLIENT_PERSISTENT), $ctx);
    if(!$this->sslStreams[$development]){
        $this->_triggerError("Failed to connect to APNS: {$error} {$errorString}.");
        unset($this->sslStreams[$development]);
        return false;
    }
    return $this->sslStreams[$development];
}

apns.log文件显示错误“无法连接到apns:110连接超时。”

没有犯错误。为什么我会收到通知而不向ios设备发送通知?有人能为我指路吗?