diff --git a/kamailio/default.cfg b/kamailio/default.cfg
index 2a51238..899efe5 100644
--- a/kamailio/default.cfg
+++ b/kamailio/default.cfg
@@ -706,7 +706,7 @@ route[INTERNAL_TO_EXTERNAL_RELAY]
 
     t_on_reply("EXTERNAL_REPLY");
 
-    t_set_fr(0, $sel(cfg_get.kazoo.to_external_no_response_timer));
+    t_set_fr(0, $sel(cfg_get.kazoo.to_external_no_response_initial_timer));
 
     t_relay();
 }
@@ -723,7 +723,7 @@ route[EXTERNAL_TO_INTERNAL_RELAY]
     t_on_reply("INTERNAL_REPLY");
     t_on_failure("INTERNAL_FAULT");
 
-    t_set_fr(0, $sel(cfg_get.kazoo.to_internal_no_response_timer));
+    t_set_fr(0, $sel(cfg_get.kazoo.to_internal_no_response_initial_timer));
 
     #!ifdef WITH_INTERNAL_LISTENER
     xlog("L_DEBUG", "$ci|route|routing to internal thru PORT_PROTO_INTERNAL_LISTENER\n");
@@ -737,6 +737,12 @@ onreply_route[EXTERNAL_REPLY]
 {
     xlog("L_INFO", "$ci|log|external reply $T_reply_code $T_reply_reason\n");
 
+    if($rs == 100) {
+        t_set_fr(0, $sel(cfg_get.kazoo.to_external_no_response_100_timer));
+    } else if(status=~"[1][8][0-9]") {
+        t_set_fr(0, $sel(cfg_get.kazoo.to_external_no_response_18X_timer));
+    }
+
     #!ifdef NAT_TRAVERSAL_ROLE
     if(status=~"[12][0-9][0-9]") {
         route(NAT_MANAGE);
@@ -763,6 +769,16 @@ onreply_route[INTERNAL_REPLY]
         xlog("L_DEBUG", "$ci|log|source $si:$sp\n");
     }
 
+    if($rs == 100) {
+        t_set_fr(0, $sel(cfg_get.kazoo.to_internal_no_response_100_timer));
+    } else if(status=~"[1][8][0-9]") {
+        t_set_fr(0, $sel(cfg_get.kazoo.to_internal_no_response_18X_timer));
+    }
+
+    if($rs == 100) {
+        t_set_fr(0, $sel(cfg_get.kazoo.to_internal_no_response_100_timer));
+    }
+
     #!ifdef NAT_TRAVERSAL_ROLE
     if(status=~"[12][0-9][0-9]") {
         route(NAT_MANAGE);
diff --git a/kamailio/defs.cfg b/kamailio/defs.cfg
index 1e321d9..8f2f6ca 100644
--- a/kamailio/defs.cfg
+++ b/kamailio/defs.cfg
@@ -7,11 +7,21 @@
 
 #!substdef "!MAJOR!$(version(num){re.subst,/^(([^\.])*\.([^\.])*)\..*/\1/})!g"
 
-#!trydef EXTERNAL_TO_INTERNAL_NO_RESPONSE_TIMER 2500
-#!trydef INTERNAL_TO_EXTERNAL_NO_RESPONSE_TIMER 3500
+#!trydef EXTERNAL_TO_INTERNAL_NO_RESPONSE_INITIAL_TIMER 2000
+#!trydef INTERNAL_TO_EXTERNAL_NO_RESPONSE_INITIAL_TIMER 2500
 
-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"
+#!trydef EXTERNAL_TO_INTERNAL_NO_RESPONSE_100_TIMER 4500
+#!trydef INTERNAL_TO_EXTERNAL_NO_RESPONSE_100_TIMER 4500
+
+#!trydef EXTERNAL_TO_INTERNAL_NO_RESPONSE_18X_TIMER 45000
+#!trydef INTERNAL_TO_EXTERNAL_NO_RESPONSE_18X_TIMER 45000
+
+kazoo.to_internal_no_response_initial_timer = EXTERNAL_TO_INTERNAL_NO_RESPONSE_INITIAL_TIMER descr "external to internal initial no response timer"
+kazoo.to_external_no_response_initial_timer = INTERNAL_TO_EXTERNAL_NO_RESPONSE_INITIAL_TIMER descr "internal to external initial no response timer"
+kazoo.to_internal_no_response_100_timer = EXTERNAL_TO_INTERNAL_NO_RESPONSE_100_TIMER descr "external to internal no response timer after 100"
+kazoo.to_external_no_response_100_timer = INTERNAL_TO_EXTERNAL_NO_RESPONSE_100_TIMER descr "internal to external no response timer after 100"
+kazoo.to_internal_no_response_18X_timer = EXTERNAL_TO_INTERNAL_NO_RESPONSE_18X_TIMER descr "external to internal no response timer after 18X"
+kazoo.to_external_no_response_18X_timer = INTERNAL_TO_EXTERNAL_NO_RESPONSE_18X_TIMER descr "internal to external no response timer after 18X"
 
 #!ifndef MY_HOSTNAME
 #!substdef "!MY_HOSTNAME!$HN(f)!g"