Thank you Dusty,
could you please provide complete URL for your "doc/ldap_howto.txt", I'd a look to http://www.freeradius.org/doc/ , but didn't find it.
Hmm, used to be in the doc directory when you untarred the source. Maybe its too old now. Its still up at http://doris.name/radius. I'm not actually using distributed directories, its a pretty simple setup here for me. Perhaps you can contribute some documentation of your setup when you've completed it.
My interest in LDAP is not related to performance but to the scalability (distributed directories, referrals, etc...) that it provides compared to SQL. The system is already working with LDAP as backend database, but only as free access. In these day we are developing the prepaid solution for Wi-Fi access (scratch cards), but completely with mySQL, because it is simpler to use (tables radacct, radcheck, etc... are already built) and develop. As we arrive to a stable solution it is my intention to move the authentication process to openLDAP.
I'm doing wifi prepaid w/ mysql right now too and I'm in the process of moving that to ldap. Once I get it built and documented I'll let you know how I did it.