Hello, I am facing the same problem. My case is all H.323 IP Phones are able to registered successfully. But I have problem only with SIP IP Phones, which cannot be registered.
I searched in the mailing list and i found that Digest type of authuntication can solve the problem. i did the configuration according to draft-sterman-aaa-sip-00.txt. But no luck :) If you find your solutions please let us know to solve others problem. Thank You Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html