Soap API Web Service不使用with function

Link WSDL: https://east-a-xxxxxxx.net/xxxx.asmx. I using SOAP of php to get function, but have error:

stdClass Object
(
 [AuthenticateConsumerResult] => stdClass Object
     (
         [Exception] => stdClass Object
          (
             [Message] => Missing configuration item(s).
             [TypeName] => CSI.API.Exceptions.AuthenticationException
             [ExceptionString] => CSI.API.Exceptions.AuthenticationException: Missing configuration item(s).
          )
        [IsException] => 1
     )
)

Source:

$client = new SoapClient("https://east-a-xxxxxxx.net/xxxx.asmx?WSDL");
$auth = array(
     'consumerName'=>'xxx',
     'consumerPassword'=>'xxxxx',
);
echo '<pre>';
print_r($client->AuthenticateConsumer($auth));
echo '</pre>';

From the above exception, I guess that there are problem in WS. You should contact with WS backend.