Hallo,
As I can use the configuration of the realm on tomcat 4 in the version embedded jboss 3.2.3
This is the code that i use on my tomcat 4.1

Realm className="org.apache.catalina.realm.JNDIRealm"
debug="99" connectionURL="ldap://192.168.0.6:389"
userPattern="uid={0},ou=people,dc=xxx,dc=xxxx,dc=it"
roleBase="ou=groups,dc=xxx,dc=xxx,dc=it" roleName="cn"
roleSearch="(uniqueMember={0})"

thanks for help me