The tc5-cluster-service.xml file is in the /server/all/deploy directory. It's definitely necessary; nothing in jboss-web.xml will provide clustered SSO.
ok, thanks. But I wasn't found any documentation about this theme. Can you tell me some link or place where I cant see?.
You mentioned the wiki page, so you probably saw this
The ClusteredSSO valve is a subclass of the valve that comes with standalone Tomcat, so the Tomcat docs apply as well:
http://jakarta.apache.org/tomcat/tomcat-5.5-doc/config/valve.html (at the bottom).
Improving the wiki page is on my todo list, but might be a while :(