diff --git a/tests/app/app-init.c b/tests/app/app-init.c
index acf09025a..5900967c3 100644
--- a/tests/app/app-init.c
+++ b/tests/app/app-init.c
@@ -54,14 +54,32 @@ int app_initialize(const char *const argv[])
         pcrf_thread = test_child_create("pcrf", argv_out);
     if (ogs_config()->parameter.no_hss == 0)
         hss_thread = test_child_create("hss", argv_out);
+
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
     if (ogs_config()->parameter.no_upf == 0)
         upf_thread = test_child_create("upf", argv_out);
     if (ogs_config()->parameter.no_sgwu == 0)
         sgwu_thread = test_child_create("sgwu", argv_out);
-    if (ogs_config()->parameter.no_smf == 0)
-        smf_thread = test_child_create("smf", argv_out);
     if (ogs_config()->parameter.no_sgwc == 0)
         sgwc_thread = test_child_create("sgwc", argv_out);
+
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
+    if (ogs_config()->parameter.no_smf == 0)
+        smf_thread = test_child_create("smf", argv_out);
     if (ogs_config()->parameter.no_mme == 0)
         mme_thread = test_child_create("mme", argv_out);
 
diff --git a/tests/app/epc-init.c b/tests/app/epc-init.c
index 06757dfd6..cd14e2691 100644
--- a/tests/app/epc-init.c
+++ b/tests/app/epc-init.c
@@ -55,15 +55,33 @@ int app_initialize(const char *const argv[])
         pcrf_thread = test_child_create("pcrf", argv_out);
     if (ogs_config()->parameter.no_hss == 0)
         hss_thread = test_child_create("hss", argv_out);
+
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
     if (ogs_config()->parameter.no_upf == 0)
         upf_thread = test_child_create("upf", argv_out);
     if (ogs_config()->parameter.no_sgwu == 0)
         sgwu_thread = test_child_create("sgwu", argv_out);
-    if (ogs_config()->parameter.no_smf == 0)
-        smf_thread = test_child_create("smf", argv_out);
     if (ogs_config()->parameter.no_sgwc == 0)
         sgwc_thread = test_child_create("sgwc", argv_out);
 
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
+    if (ogs_config()->parameter.no_smf == 0)
+        smf_thread = test_child_create("smf", argv_out);
+
     ogs_sctp_init(ogs_config()->usrsctp.udp_port);
 
     rv = mme_initialize();
diff --git a/tests/csfb/abts-main.c b/tests/csfb/abts-main.c
index c584ab062..29203c30d 100644
--- a/tests/csfb/abts-main.c
+++ b/tests/csfb/abts-main.c
@@ -88,15 +88,34 @@ static void initialize(const char *const argv[])
         pcrf_thread = test_child_create("pcrf", argv);
     if (ogs_config()->parameter.no_hss == 0)
         hss_thread = test_child_create("hss", argv);
+
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
     if (ogs_config()->parameter.no_upf == 0)
         upf_thread = test_child_create("upf", argv);
     if (ogs_config()->parameter.no_sgwu == 0)
         sgwu_thread = test_child_create("sgwu", argv);
-    if (ogs_config()->parameter.no_smf == 0)
-        smf_thread = test_child_create("smf", argv);
     if (ogs_config()->parameter.no_sgwc == 0)
         sgwc_thread = test_child_create("sgwc", argv);
 
+
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
+    if (ogs_config()->parameter.no_smf == 0)
+        smf_thread = test_child_create("smf", argv);
+
     test_epc_init();
     ogs_sctp_init(ogs_config()->usrsctp.udp_port);
 
diff --git a/tests/cups/abts-main.c b/tests/cups/abts-main.c
index 39478368a..14cd46be1 100644
--- a/tests/cups/abts-main.c
+++ b/tests/cups/abts-main.c
@@ -54,6 +54,14 @@ static void initialize(const char *const argv[])
     rv = app_initialize(argv);
     ogs_assert(rv == OGS_OK);
 
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
     rv = pcscf_fd_init();
     ogs_assert(rv == OGS_OK);
 }
@@ -65,7 +73,6 @@ int main(int argc, const char *const argv[])
 
     atexit(terminate);
     test_5gc_run(argc, argv, "cups.yaml", initialize);
-    ogs_msleep(1000);
 
     for (i = 0; alltests[i].func; i++)
         suite = alltests[i].func(suite);
diff --git a/tests/mnc3/abts-main.c b/tests/mnc3/abts-main.c
index aa45c2019..fd481e7bf 100644
--- a/tests/mnc3/abts-main.c
+++ b/tests/mnc3/abts-main.c
@@ -58,7 +58,6 @@ int main(int argc, const char *const argv[])
 
     atexit(terminate);
     test_5gc_run(argc, argv, "mnc3.yaml", initialize);
-    ogs_msleep(1000);
 
     for (i = 0; alltests[i].func; i++)
         suite = alltests[i].func(suite);
diff --git a/tests/volte/abts-main.c b/tests/volte/abts-main.c
index a12b60952..7811e9e48 100644
--- a/tests/volte/abts-main.c
+++ b/tests/volte/abts-main.c
@@ -54,6 +54,14 @@ static void initialize(const char *const argv[])
     rv = app_initialize(argv);
     ogs_assert(rv == OGS_OK);
 
+    /*
+     * To avoid freeDiameter error
+     *
+     * ROUTING ERROR
+     * 'No remaining suitable candidate to route the message to' for:
+     */
+    ogs_msleep(300);
+
     rv = pcscf_fd_init();
     ogs_assert(rv == OGS_OK);
 }
@@ -65,7 +73,6 @@ int main(int argc, const char *const argv[])
 
     atexit(terminate);
     test_5gc_run(argc, argv, "volte.yaml", initialize);
-    ogs_msleep(1000);
 
     for (i = 0; alltests[i].func; i++)
         suite = alltests[i].func(suite);