to answer my own question the mapping between the fields in the abstract persistence schema and database schema is not specified by the EJB 2.0 specification. the mapping is done in a vendor specific manor. in JBoss v3.0 you use the jbosscmp-jdbc.xml descriptor file to describe this mapping.
apparently the JNDI name under which an EJB is bound in deployment is also outside of the EJB specification. the JNDI name can be specified in jboss.xml descriptor in JBoss v3.0. if this descriptor is not present ejb-name is used as the beans JNDI name.