[Freeswitch-dev] how the ldap schema for freeswitch is designed ? is there the schema file in the freeswitch's source folder?

I am implementing ldap schema for keeping the registered aor records. I don't know whether the ldap schema for sip is standard. I found the freeswitch has some configuration about it, but I can't find the schema files. can somebody give me some cue about it? Thanks.