Aansturen Zebra printer lokaal lukt wel maar via VPS niet

<?php
error_reporting(E_ALL);

/* Get the port for the service. */
$port = "9100";

/* Get the IP address for the target host. */
$host = "192.168.68.133";

/* construct the label */
$label  =  "^XA";
$label .=  "^FO50,50^BCN,100,Y,N,N,A^FD290001744001^FS ";
$label .=  "^PQ1" ;//aantal labels
$label .=  " ^XZ";



$socket = @socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
if ($socket === false) {
    echo "socket_create() failed: reason: " . socket_strerror(socket_last_error()) . "\n";
} else {
    echo "socket created<br>";
}

echo "Attempting to connect to '$host' on port '$port'...<br>";

$result = @socket_connect($socket, $host, $port);

if ($result === false) {
    echo "socket_connect() failed.\nReason: ($result) " . socket_strerror(socket_last_error($socket)) . "<br>";
} else {
    echo "Connected<br>";
}

socket_write($socket, $label, strlen($label));
socket_close($socket);?>