Wirhindlg route

route[WITHINDLG] {
        if (has_totag()) {
                # sequential request withing a dialog should
                # take the path determined by record-routing
                if (loose_route()) {

                        if ($du == "") {
                                if (!handle_ruri_alias()) {
                                        xlog("L_ERR", "Bad alias <$ru>\n");
                                        sl_send_reply("400", "Bad Request");
                                        exit;
                                }
                        }
#                       else
#                               route(DLGURI);

                        xlog("==> duri=[$du]");

                        if ( is_method("ACK") ) {
                                # ACK is forwarded statelessy
                                route(NATMANAGE);
                        }
                        route(RELAY);
                } else {
                        if ( is_method("ACK") ) {
                                if ( t_check_trans() ) {
                                        # no loose-route, but stateful ACK;
                                        # must be an ACK after a 487
                                        # or e.g. 404 from upstream server
                                        route(RELAY);
                                        exit;
                                } else {
                                        # ACK without matching transaction ... ignore and discard
                                        exit;
                                }
                        }
                        sl_send_reply("404","Not here");
                }
                exit;
        }
}