## to be enhanced

route[AUTHORIZATION_CHECK]
{
    if (!is_method("MESSAGE|NOTIFY|SUBSCRIBE|PUBLISH"))
        return;

    if(has_totag())
        return;

    if (isflagset(FLAG_INTERNALLY_SOURCED))
        return;

    if (isflagset(FLAG_TRUSTED_SOURCE))
        return;

    $xavp(regcfg=>match_received) = $su;
    if(!(registered("location", "$fu", 2, 1) == 1 && $(xavp(ulattrs=>custom_channel_vars){s.len}) > 1)) {
        xlog("L_INFO", "$ci|log|not authorized $fu from $si:$sp\n");
        send_reply("503", "Not Registered");
        exit;
    }
}