no need for extra setup (#142)

nat correction
sip headers

kamailio/dispatcher-role.cfg

@@ -123,7 +123,10 @@ route[DISPATCHER_REDIRECT]
         xlog("L_INFO", "$ci|log|found redirect for $var(redirect) : $var(prefered_route)\n");
         $du = $var(prefered_route);
         $avp(AVP_REDIRECT_KEY) = $var(redirect);
-        route(EXTERNAL_TO_INTERNAL_RELAY);
+        t_on_reply("INTERNAL_REPLY");
+        t_on_failure("INTERNAL_FAULT");
+        t_set_fr(0, 1000);
+        t_relay();
         exit();
     }
 }