Fehler bei SOAP API?

# Configuration parameters:
  $user = 'admin';
  $pass = 'xxxxx';
  $url  = 'https://xxx/liveconfig/soap';


  # Construct WSDL URL
  $wsdl_url = $url
             .'?wsdl'
             .'&l=' . urlencode($user)
             .'&p=' . urlencode($pass);


  # Create SOAP client
  $client = new SoapClient($wsdl_url,
                           array('style'    => SOAP_DOCUMENT,
                                 'use'      => SOAP_LITERAL,
                                )
                          );


  # Construct SOAP token:
  $ts = gmdate("Y-m-d") . "T" . gmdate("H:i:s") . ".000Z";
  $token = base64_encode(hash_hmac('sha1',
                                   'LiveConfig' . $user . 'HostingDomainAdd' . $ts,
                                   $pass,
                                   true
                                  )
                        );


  $auth = array('login'     => $user,
                'timestamp' => $ts,
                'token'     => $token);
  $subs = "web".$kundennummer;
  $params = array('auth'      => $auth,
  		'subscription' => 'web15',
		'domain' => 'strato.de',
		'mail' => '1',
		'web' => '/');


  try {
    $response = $client->HostingDomainAdd($params);
  } catch (SoapFault $soapFault) {
    die("useradd Error while calling Web Service: " . $soapFault->faultstring . "\n");
  }