Moved to the remoting user forum.
I forgott to say that is not a Java application on the other side and that we do not serialize objects. It's plain text messages (XML).
You could use JBossRemoting with the socket transport and the http marshaller/unmarshaller (which handled plain text). The doc is at http://labs.jboss.com/portal/jbossremoting/docs/guide/index.html.
The locator url to use would be socket://myhost:5400/?datatype=http