Remote authentication via LDAP

Hi everyone!

i need to authenticate local sip user with an external LDAP server. I’m currently use Trixbox (Asterisk 1.6).
Configuring the res_ldap.conf, and extconfig.conf files, i can manage correctly realtime sipusers using the parameter stored in the LDAP database and everything works fine.

However i need only that local users can retrieve the user password located in an LDAP server in order to make registration (authentication), i.e. i need only a centralized managment of the password in LDAP not of all sip parameters.

Can someone help me?

Thanks in advance

Andrea