LDAP Shared roster with users from another domain (jabber server)?

I’'ve recently switched to LDAP (Fedora Directory Server) and managed to configure it in order to have authentification and groups with LDAP but I found no way of adding a user from other domain in a shared roster (ldap).

usernames in ldap are like “name.surname” and adding thins kind of users in LDAP group will me them appear in shared roster.

But how to add somebody@otherdomain.com to the shared roster group in LDAP? i’‘ve tried to add somebody@otherdomain.com as a user in ldap but it doesn’‘t work - the users apear in the roster but it’'s always offline.