"There are a few prerequisites to discuss before covering the
configuration of Asterisk. First, my instructions assume that you
have already installed Fedora 9. Second, you must have an existing
LDAP server. The LDAP schema I use in this article is compatible
with Fedora Directory Server. I recommend using the FreeIPA system
to manage FDS. Fedora 9 provides packages for both FDS
(fedora-ds-base) and FreeIPA (ipa-server). Finally, the machine
hosting Asterisk must allow incoming UDP connections to ports 5060
(Session Initiation Protocol) and 69 (TFTP) to pass through its
firewall."