JSESSIONID pitfalls

[nimo22]

I want to rename JSESSIONID within jboss as 7 container and has two possible ways:

1. Way:

-Dorg.apache.catalina.SESSION_COOKIE_NAME=MYID
-Dorg.apache.catalina.SESSION_PARAMETER_NAME=myid

2. Way:

-Dorg.apache.catalina.JSESSIONID=SID

I have the following questions:

1. Where lies the difference between Way 1 and Way 2 ?
2. In "Way 2", I only rename the SESSION_COOKIE_NAME and not the SESSION_PARAMETER_NAME, am I right? To rename the SESSION_PARAMETER_NAME, I also can use -Dorg.apache.catalina.jsessionid=SID, am I right?
3. Are there any disadvandtages to rename the default JSESSIONID/jsessionid to something else? The Tomcat Specifications says (http://tomcat.apache.org/tomcat-6.0-doc/config/systemprops.html):"Note that the Servlet specification requires this to be jsessionid/JSESSIONID. You should not rely on being able to change this."What does this mean? Are there any disadvandtage to rename it? For example, broken authentication, security lacks or the like?