You have to load and configure dialog module.
This kind of questions should be addressed to sr-users@lists.sip-router.org mailing list, being Kamailio admin question related to config rather than a bug in source code. I am closing this issue, if you need further clarification, write an email to mailing list.
--- Reply to this email directly or view it on GitHub: https://github.com/kamailio/kamailio/issues/347#issuecomment-144035585