SQL & PL/SQL

I have a stored procedure that makes a call to a web service using the following code snippet:

......
req := utl_http.begin_request(url => p_url_in, method => 'POST');
-- Set the HTTP request headers.
utl_http.set_header(r => req, name => 'Content-Type', VALUE => p_data_type);
utl_http.set_header(r => req, name => 'Content-Length', VALUE => to_char(LENGTH(data_in)));
utl_http.set_header(r => req, name => 'MessageType', VALUE => 'CALL');

IF p_username_in IS NOT NULL THEN
utl_http.set_authentication(r => req, username => p_username_in, password => p_password_in, scheme => 'Basic', for_proxy => FALSE);
END IF;

utl_http.write_text(r => req, data => data_in);
-- Write the data to the body of the HTTP request.
utl_http.write_text(r => req, data => data_in);
-- Process the request and get the response.
resp := utl_http.get_response(r => req, return_info_response => TRUE);

.....

The problem comes if the name of the machine specified in p_url_in is present on the network but the service requested is not present, for example the web server is down, utl_http waits for about 3 minutes before returning. This is the case even if I call utl_http.set_transfer_timeout(10); before utl_http.begin_request is called, as per other posts that I have found. Is there anyway to alter the timeout for the request?

TIA

Graham Harris