Pass of parameter in query String

Hi,
i'm new to WSRP, i develop a remote portlet, i use Pluto to Producer (using
wsrp4j) and consume the portlet in Liferay 4.0 (or uPortal).
I have a question:
if i write in a page jsp
<%
PortletURL url = renderResponse.createRenderURL();
url.setParameter("param","2");
%>
<A HREF="<%=url.toString()%>">Link</A>

On producer (Pluto) i can to get the parameter, but on consumer the
parameter return null..
Is possibile the passing of parameter on query string from consumer to
producer, if the response is yes, how do that??
Can you explain me with an example of cosa????

Regards.

Roberto