diff --git a/kamailio/default.cfg b/kamailio/default.cfg
index 0fc1542..edb4aa7 100644
--- a/kamailio/default.cfg
+++ b/kamailio/default.cfg
@@ -688,7 +688,7 @@ route[INTERNAL_TO_EXTERNAL_RELAY]
 
     t_on_reply("EXTERNAL_REPLY");
 
-    t_set_fr(0, 10000);
+    t_set_fr(0, $sel(cfg_get.kazoo.to_external_no_response_timer));
 
     t_relay();
 }
@@ -705,7 +705,7 @@ route[EXTERNAL_TO_INTERNAL_RELAY]
     t_on_reply("INTERNAL_REPLY");
     t_on_failure("INTERNAL_FAULT");
 
-    t_set_fr(0, 1000);
+    t_set_fr(0, $sel(cfg_get.kazoo.to_internal_no_response_timer));
 
     t_relay();
 }
diff --git a/kamailio/defs.cfg b/kamailio/defs.cfg
index 9e5df5d..bef416b 100644
--- a/kamailio/defs.cfg
+++ b/kamailio/defs.cfg
@@ -7,6 +7,12 @@
 
 #!substdef "!MAJOR!$(version(num){re.subst,/^(([^\.])*\.([^\.])*)\..*/\1/})!g"
 
+#!trydef EXTERNAL_TO_INTERNAL_NO_RESPONSE_TIMER 250
+#!trydef INTERNAL_TO_EXTERNAL_NO_RESPONSE_TIMER 500
+
+kazoo.to_internal_no_response_timer = EXTERNAL_TO_INTERNAL_NO_RESPONSE_TIMER descr "external to internal no response timer"
+kazoo.to_external_no_response_timer = INTERNAL_TO_EXTERNAL_NO_RESPONSE_TIMER descr "internal to external no response timer"
+
 #!ifndef MY_HOSTNAME
 #!substdef "!MY_HOSTNAME!$HN(f)!g"
 #!endif