CustomerDB 1.2.1 Usage

I have been looking for a centralised database for customer contact information to be stored. This looks like it might be the right Module but I can find no information on how it works - is it MYSQL backed? I would ideally like an LDAP solution as the phones I use can connect to an LDAP server and retrieve the callers details directly. Has anyone any suggestions as to which route would be best?

Thanks

Martin