sì, il web service risponde:

[wsdl]
<definitions targetNamespace="http://www.xxxxxx.com">
<types>
<xsd:schema targetNamespace="http://www.xxxxxx.com">
<xsd:import namespace="http://schemas.xmlsoap.org/soap/encoding/"/>
<xsd:import namespace="http://schemas.xmlsoap.org/wsdl/"/>
<xsd:complexType name="id">
<xsd:all>
<xsd:element name="id" type="xsd:string"/>
</xsd:all>
</xsd:complexType>
</xsd:schema>
</types>
<message name="getConnIdRequest">
<part name="user" type="xsd:string"/>
<part name="serv_user" type="xsd:string"/>
</message>
<message name="getConnIdResponse">
<part name="return" type="tns:id"/>
</message>
<portType name="id_servicePortType">
<operation name="getConnId">
<input message="tns:getConnIdRequest"/>
<output message="tns:getConnIdResponse"/>
</operation>
</portType>
<binding name="id_serviceBinding" type="tns:id_servicePortType">
<soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/>
<operation name="getConnId">
<soap:operation soapAction="http://www.xxxxxx.com/ita/codice/id_service.php/getConnId" style="rpc"/>
<input>
<soap:body use="encoded" namespace="http://www.xxxxxx.com" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</input>
<output>
<soap:body use="encoded" namespace="http://www.xxxxxx.com" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</output>
</operation>
</binding>
<service name="id_service">
<port name="id_servicePort" binding="tns:id_serviceBinding">
<soap:address location="http://www.xxxxxx.com/ita/codice/id_service.php"/>
</port>
</service>
</definitions>
[/wsdl]

[getConnId]
Name: getConnId
Binding: id_serviceBinding
Endpoint: http://www.xxxxxx.com/ita/codice/id_service.php
SoapAction: http://www.xxxxxx.com/ita/codice/id_....php/getConnId
Style: rpc
Input:
use: encoded
namespace: http://www.xxxxxx.com
encodingStyle: http://schemas.xmlsoap.org/soap/encoding/
message: getConnIdRequest
parts:
user: xsd:string
serv_user: xsd:string
Output:
use: encoded
namespace: http://www.xxxxxx.com
encodingStyle: http://schemas.xmlsoap.org/soap/encoding/
message: getConnIdResponse
parts:
return: tns:id
Namespace: http://www.xxxxxx.com
Transport: http://schemas.xmlsoap.org/soap/http
[/getConnId]

Grazie mille per ogni consiglio!
ciao
topolina