Webservice REST

I'm developing an application for android and I shold have some optimization on communications.
The thing is that I want to create the webservices in some way like REST: I call a webpage sending parameters through GET method and get a response in XML.

I already did something simple that consists in converting text to binary (coded in UTF-8) and used the HTML widget. The MIME-Type is "text/xml" and the Save to Disk is set to No.
So, I tried using my laptop and worked just fine, but when trying to invoke it using android I get no XML... the system just hangs waiting for an answer...

I set the permissins correctly (even the anonymous can access to the page).

Am I doing something wrong or what I'm trying to do is just unreachable through OutSystems?

Best regards,
Miguel Ribeiro