Hi all! Today, all things are ok (they worked!). My project is EJB3.0. Inside folder \server\default\conf, I add some informations: <application-policy name = "DB-Domain"> | <authentication> | <login-module code = "org.jboss.security.auth.spi.DatabaseServerLoginModule" | flag = "required"> | <module-option name = "unauthenticatedIdentity">guest</module-option> | <module-option name = "dsJndiName">java:/DefaultDS</module-option> | <module-option name = "principalsQuery">SELECT PASSWD FROM USERS WHERE USERID=?</module-option> | <module-option name = "rolesQuery">SELECT ROLEID, 'Roles' FROM ROLES WHERE USERID=?</module-option> | </login-module> | </authentication> | </application-policy> My jboss.xml : <jboss> | <security-domain>DB-Domain</security-domain> | <enterprise-beans> | <session> | <ejb-name>ClientActionBean</ejb-name> | <resource-ref> | <res-ref-name>jdbc/DefaultDS</res-ref-name> | <jndi-name>java:/DefaultDS</jndi-name> | </resource-ref> | </session> | </enterprise-beans> | </jboss> and ejb-jar.xml: <enterprise-beans> | <session> | <ejb-name>ClientActionBean</ejb-name> | <resource-ref> | <res-ref-name>jdbc/DefaultDS</res-ref-name> | <res-type>javax.sql.DataSource</res-type> | <res-auth>Container</res-auth> | </resource-ref> | </session> | </enterprise-beans> | <assembly-descriptor> | <Security-role> | <role-name>doctor</role-name> | </Security-role> | <Security-role> | <role-name>nurse</role-name> | </Security-role> | <method-permission> | <role-name>doctor</role-name> | <method> | <ejb-name>ClientActionBean</ejb-name> | <method-name>getCallInfo</method-name> | </method> | .... I use Eclipse to write client app, bean and package my bean enclose two file jboss.xml and ejb-jar.xml (inside META-INF). Restart server, and run client app! Note: I installed Jboss server and mySQL on the machine 1(hostname:abc), and on the machine 2 (hostname:xxx). All things ok! Hope this helps!!!! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4024535#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...