diff --git a/kamailio/auth.cfg b/kamailio/auth.cfg
index 07356a4..820264d 100644
--- a/kamailio/auth.cfg
+++ b/kamailio/auth.cfg
@@ -81,11 +81,22 @@ route[SETUP_AUTH_HEADERS]
        $xavp(hf[0]=>X-AUTH-Token) = $avp(trusted_x_header);
        $xavp(hf[0]=>X-AUTH-URI-User) = $rU;
        $xavp(hf[0]=>X-AUTH-URI-Realm) = $rd;
-       if($ai != $null) {
+       if(is_present_hf("P-Asserted-Identity") && $(ai{uri.user}) != "") {
             $xavp(hf[0]=>X-AUTH-From-User) = $(ai{uri.user});
+       } else if(is_present_hf("P-Preferred-Identity") && $pU != "") {
+            $xavp(hf[0]=>X-AUTH-From-User) = $pU;
+       } else if(is_present_hf("Remote-Party-ID") && $(re{uri.user}) != "") {
+            $xavp(hf[0]=>X-AUTH-From-User) = $(re{uri.user});
        } else {
             $xavp(hf[0]=>X-AUTH-From-User) = $fU;
        }
+       if($xavp(hf=>X-AUTH-From-User) =~ "^\+?00+$") {
+            $xavp(hf[0]=>X-AUTH-From-Is-Anonymous) = "true";
+            $xavp(hf[0]=>X-AUTH-From-User) = $null;
+       } else if($(xavp(hf=>X-AUTH-From-User){s.tolower}) =~ "^anonymous$") {
+            $xavp(hf[0]=>X-AUTH-From-Is-Anonymous) = "true";
+            $xavp(hf[0]=>X-AUTH-From-User) = $null;
+       }
        return;
    }