kamailio config snippet

loadmodule "ndb_redis.so"
loadmodule "topos.so"
loadmodule "topos_redis.so"

modparam("ndb_redis", "server", "name=localsrv;addr=127.0.0.1;port=6379;db=1")
modparam("topos", "storage", "redis")
modparam("topos_redis", "serverid", "localsrv")

/* Main SIP request routing logic
 * - processing of any incoming SIP request starts with this route
 * - note: this is the same as route { ... } */
request_route {

/* 8< cut parts basically same as default 8< */

        # handle requests within SIP dialogs
        route(WITHINDLG);

        ### only initial requests (no To tag)

        dlg_manage();

        # record routing for dialog forming requests (in case they are routed)
        # - remove preloaded route headers
        remove_hf("Route");
        record_route();

        # account only INVITEs
        if (is_method("INVITE")) {
                #setflag(FLT_ACC); # do accounting
                add_path();
        }

/* 8< cut parts basically same as default 8< */

        # reply fast 100 on register
        if (is_method("REGISTER"))
                sl_send_reply("100","Trying");

        route(RELAY);

        exit;
}


# Handle requests within SIP dialogs
route[WITHINDLG] {
        if (!has_totag()) return;

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

                route(DLGURI);
                if ( is_method("ACK") ) {
                        # ACK is forwarded statelessly
                        route(NATMANAGE);
                } else if ( is_method("NOTIFY") ) {
                        # Add Record-Route for in-dialog NOTIFY as per RFC 6665.
                        record_route();
                }
                route(RELAY);
                exit;
        }

        if (is_method("SUBSCRIBE") && uri == myself) {
                # in-dialog subscribe requests
                sl_send_reply("404", "No voicemail service");
                exit;
        }
        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;
}