[otrs] Defining agents - LDAP

I have set up OTRS with LDAP authentication, and got it to work with users I define in OTRS. Is it possible to not define the users in OTRS at all, and let it use the LDAP for all other user information? - I checked, and no. To do that would mean that instead of querying the OTRS database for information about the user, OTRS would have to query LDAP. (once it got the user info, including UserNumber, it could save the user data in the local table). I cannot understand why do I need to define users that are already defined in LDAP. This is a common theme with most applications that have the concept of users. Dan