diff --git a/tests/scripts/thread-cert/Cert_5_1_01_RouterAttach.py b/tests/scripts/thread-cert/Cert_5_1_01_RouterAttach.py
index a3f79264a..5c91aa520 100755
--- a/tests/scripts/thread-cert/Cert_5_1_01_RouterAttach.py
+++ b/tests/scripts/thread-cert/Cert_5_1_01_RouterAttach.py
@@ -79,7 +79,7 @@ class Cert_5_1_01_RouterAttach(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(7)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.collect_rloc16s()
diff --git a/tests/scripts/thread-cert/Cert_5_1_02_ChildAddressTimeout.py b/tests/scripts/thread-cert/Cert_5_1_02_ChildAddressTimeout.py
index ae03a24bf..ad42c8292 100755
--- a/tests/scripts/thread-cert/Cert_5_1_02_ChildAddressTimeout.py
+++ b/tests/scripts/thread-cert/Cert_5_1_02_ChildAddressTimeout.py
@@ -97,7 +97,7 @@ class Cert_5_1_02_ChildAddressTimeout(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MED].start()
diff --git a/tests/scripts/thread-cert/Cert_5_1_03_RouterAddressReallocation.py b/tests/scripts/thread-cert/Cert_5_1_03_RouterAddressReallocation.py
index ffa991432..2b9a652e5 100755
--- a/tests/scripts/thread-cert/Cert_5_1_03_RouterAddressReallocation.py
+++ b/tests/scripts/thread-cert/Cert_5_1_03_RouterAddressReallocation.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import network_layer
 import thread_cert
@@ -84,11 +85,11 @@ class Cert_5_1_03_RouterAddressReallocation(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER2].set_network_id_timeout(110)
diff --git a/tests/scripts/thread-cert/Cert_5_1_04_RouterAddressReallocation.py b/tests/scripts/thread-cert/Cert_5_1_04_RouterAddressReallocation.py
index 76d07d788..13f014855 100755
--- a/tests/scripts/thread-cert/Cert_5_1_04_RouterAddressReallocation.py
+++ b/tests/scripts/thread-cert/Cert_5_1_04_RouterAddressReallocation.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import network_layer
 import thread_cert
@@ -86,11 +87,11 @@ class Cert_5_1_04_RouterAddressReallocation(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER2].set_network_id_timeout(200)
diff --git a/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py b/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py
index 46cb5dcfc..8e551d164 100755
--- a/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py
+++ b/tests/scripts/thread-cert/Cert_5_1_05_RouterAddressTimeout.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import network_layer
 import thread_cert
@@ -82,7 +83,7 @@ class Cert_5_1_05_RouterAddressTimeout(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER1].reset()
diff --git a/tests/scripts/thread-cert/Cert_5_1_06_RemoveRouterId.py b/tests/scripts/thread-cert/Cert_5_1_06_RemoveRouterId.py
index 73c4c4ef5..d32bed0a7 100755
--- a/tests/scripts/thread-cert/Cert_5_1_06_RemoveRouterId.py
+++ b/tests/scripts/thread-cert/Cert_5_1_06_RemoveRouterId.py
@@ -79,7 +79,7 @@ class Cert_5_1_06_RemoveRouterId(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
         rloc16 = self.nodes[ROUTER1].get_addr16()
         self.collect_rloc16s()
diff --git a/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py b/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py
index b6364d996..a1c0bd600 100755
--- a/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py
+++ b/tests/scripts/thread-cert/Cert_5_1_07_MaxChildCount.py
@@ -156,7 +156,7 @@ class Cert_5_1_07_MaxChildCount(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         for i in range(3, 13):
diff --git a/tests/scripts/thread-cert/Cert_5_1_08_RouterAttachConnectivity.py b/tests/scripts/thread-cert/Cert_5_1_08_RouterAttachConnectivity.py
index bf1f0a14d..b901089d3 100755
--- a/tests/scripts/thread-cert/Cert_5_1_08_RouterAttachConnectivity.py
+++ b/tests/scripts/thread-cert/Cert_5_1_08_RouterAttachConnectivity.py
@@ -99,7 +99,7 @@ class Cert_5_1_08_RouterAttachConnectivity(thread_cert.TestCase):
         for i in range(2, 5):
             self.nodes[i].start()
 
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         for i in range(2, 5):
             self.assertEqual(self.nodes[i].get_state(), 'router')
@@ -107,7 +107,7 @@ class Cert_5_1_08_RouterAttachConnectivity(thread_cert.TestCase):
         self.simulator.go(config.MAX_ADVERTISEMENT_INTERVAL)
 
         self.nodes[ROUTER4].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER4].get_state(), 'router')
 
     def verify(self, pv):
diff --git a/tests/scripts/thread-cert/Cert_5_1_09_REEDAttachConnectivity.py b/tests/scripts/thread-cert/Cert_5_1_09_REEDAttachConnectivity.py
index 33bad5cff..b17518639 100755
--- a/tests/scripts/thread-cert/Cert_5_1_09_REEDAttachConnectivity.py
+++ b/tests/scripts/thread-cert/Cert_5_1_09_REEDAttachConnectivity.py
@@ -101,7 +101,7 @@ class Cert_5_1_09_REEDAttachConnectivity(thread_cert.TestCase):
         for i in range(2, 5):
             self.nodes[i].start()
 
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
         self.assertEqual(self.nodes[REED1].get_state(), 'child')
@@ -110,7 +110,7 @@ class Cert_5_1_09_REEDAttachConnectivity(thread_cert.TestCase):
         self.simulator.go(config.MAX_ADVERTISEMENT_INTERVAL)
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
         self.assertEqual(self.nodes[REED1].get_state(), 'router')
 
diff --git a/tests/scripts/thread-cert/Cert_5_1_10_RouterAttachLinkQuality.py b/tests/scripts/thread-cert/Cert_5_1_10_RouterAttachLinkQuality.py
index 5c60106cf..501659355 100755
--- a/tests/scripts/thread-cert/Cert_5_1_10_RouterAttachLinkQuality.py
+++ b/tests/scripts/thread-cert/Cert_5_1_10_RouterAttachLinkQuality.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_PARENT_RESPONSE, MLE_CHILD_ID_REQUEST, SOURCE_ADDRESS_TLV, MODE_TLV, TIMEOUT_TLV, CHALLENGE_TLV, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, ADDRESS16_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, TLV_REQUEST_TLV, SCAN_MASK_TLV, CONNECTIVITY_TLV, LINK_MARGIN_TLV, VERSION_TLV, ADDRESS_REGISTRATION_TLV
@@ -90,15 +91,15 @@ class Cert_5_1_10_RouterAttachLinkQuality(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER3].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER3].get_state(), 'router')
 
     def verify(self, pv):
diff --git a/tests/scripts/thread-cert/Cert_5_1_11_REEDAttachLinkQuality.py b/tests/scripts/thread-cert/Cert_5_1_11_REEDAttachLinkQuality.py
index 0da95cd01..85cb3c7f0 100755
--- a/tests/scripts/thread-cert/Cert_5_1_11_REEDAttachLinkQuality.py
+++ b/tests/scripts/thread-cert/Cert_5_1_11_REEDAttachLinkQuality.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_PARENT_RESPONSE, MLE_CHILD_ID_REQUEST, SOURCE_ADDRESS_TLV, MODE_TLV, TIMEOUT_TLV, CHALLENGE_TLV, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, ADDRESS16_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, TLV_REQUEST_TLV, SCAN_MASK_TLV, CONNECTIVITY_TLV, LINK_MARGIN_TLV, VERSION_TLV, ADDRESS_REGISTRATION_TLV
@@ -92,15 +93,15 @@ class Cert_5_1_11_REEDAttachLinkQuality(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[REED].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[REED].get_state(), 'child')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
         self.assertEqual(self.nodes[REED].get_state(), 'router')
 
diff --git a/tests/scripts/thread-cert/Cert_5_1_12_NewRouterNeighborSync.py b/tests/scripts/thread-cert/Cert_5_1_12_NewRouterNeighborSync.py
index 5c2917c02..304d3d559 100755
--- a/tests/scripts/thread-cert/Cert_5_1_12_NewRouterNeighborSync.py
+++ b/tests/scripts/thread-cert/Cert_5_1_12_NewRouterNeighborSync.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_PARENT_RESPONSE, MLE_CHILD_UPDATE_RESPONSE, MLE_CHILD_ID_REQUEST, MLE_CHILD_ID_RESPONSE, MLE_LINK_REQUEST, MLE_LINK_ACCEPT, MLE_LINK_ACCEPT_AND_REQUEST, ADDR_SOL_URI, SOURCE_ADDRESS_TLV, MODE_TLV, TIMEOUT_TLV, CHALLENGE_TLV, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, MLE_FRAME_COUNTER_TLV, ROUTE64_TLV, ADDRESS16_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, TLV_REQUEST_TLV, SCAN_MASK_TLV, CONNECTIVITY_TLV, LINK_MARGIN_TLV, VERSION_TLV, ADDRESS_REGISTRATION_TLV, NL_MAC_EXTENDED_ADDRESS_TLV, NL_RLOC16_TLV, NL_STATUS_TLV, NL_ROUTER_MASK_TLV, COAP_CODE_ACK
@@ -81,11 +82,11 @@ class Cert_5_1_12_NewRouterSync(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/Cert_5_1_13_RouterReset.py b/tests/scripts/thread-cert/Cert_5_1_13_RouterReset.py
index 54555019b..e1ece81a6 100755
--- a/tests/scripts/thread-cert/Cert_5_1_13_RouterReset.py
+++ b/tests/scripts/thread-cert/Cert_5_1_13_RouterReset.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_LINK_REQUEST, MLE_LINK_ACCEPT, MLE_LINK_ACCEPT_AND_REQUEST, SOURCE_ADDRESS_TLV, CHALLENGE_TLV, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, ROUTE64_TLV, ADDRESS16_TLV, LEADER_DATA_TLV, TLV_REQUEST_TLV, VERSION_TLV, MLE_MAX_RESPONSE_DELAY
@@ -83,7 +84,7 @@ class Cert_5_1_13_RouterReset(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
         self.collect_rloc16s()
 
@@ -92,7 +93,7 @@ class Cert_5_1_13_RouterReset(thread_cert.TestCase):
         self.simulator.go(5)
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
     def verify(self, pv):
diff --git a/tests/scripts/thread-cert/Cert_5_2_01_REEDAttach.py b/tests/scripts/thread-cert/Cert_5_2_01_REEDAttach.py
index ae0cc6eaf..230c6e372 100755
--- a/tests/scripts/thread-cert/Cert_5_2_01_REEDAttach.py
+++ b/tests/scripts/thread-cert/Cert_5_2_01_REEDAttach.py
@@ -96,11 +96,11 @@ class Cert_5_2_01_REEDAttach(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[DUT_ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER1].get_state(), 'router')
 
         self.nodes[REED1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[REED1].get_state(), 'child')
 
         self.nodes[MED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_2_03_LeaderReject2Hops.py b/tests/scripts/thread-cert/Cert_5_2_03_LeaderReject2Hops.py
index e91509a86..35480c8f1 100755
--- a/tests/scripts/thread-cert/Cert_5_2_03_LeaderReject2Hops.py
+++ b/tests/scripts/thread-cert/Cert_5_2_03_LeaderReject2Hops.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import network_layer
 import thread_cert
@@ -315,16 +316,16 @@ class Cert_5_2_3_LeaderReject2Hops(thread_cert.TestCase):
 
         for i in range(2, 32):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
         self.collect_rlocs()
 
         self.nodes[ROUTER_31].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER_31].get_state(), 'router')
 
         self.nodes[ROUTER_32].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
     def verify(self, pv: PacketVerifier):
         pkts = pv.pkts
diff --git a/tests/scripts/thread-cert/Cert_5_2_04_REEDUpgrade.py b/tests/scripts/thread-cert/Cert_5_2_04_REEDUpgrade.py
index 20aafa212..e5c9b1449 100755
--- a/tests/scripts/thread-cert/Cert_5_2_04_REEDUpgrade.py
+++ b/tests/scripts/thread-cert/Cert_5_2_04_REEDUpgrade.py
@@ -174,11 +174,11 @@ class Cert_5_2_4_REEDUpgrade(thread_cert.TestCase):
 
         for i in range(2, 17):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[DUT_REED].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.simulator.go(ROUTER_SELECTION_JITTER)
 
         self.collect_rloc16s()
diff --git a/tests/scripts/thread-cert/Cert_5_2_05_AddressQuery.py b/tests/scripts/thread-cert/Cert_5_2_05_AddressQuery.py
index d6f352af7..9abe1556f 100755
--- a/tests/scripts/thread-cert/Cert_5_2_05_AddressQuery.py
+++ b/tests/scripts/thread-cert/Cert_5_2_05_AddressQuery.py
@@ -184,7 +184,7 @@ class Cert_5_2_5_AddressQuery(thread_cert.TestCase):
 
         # 2. BR: SLAAC Server for prefix 2002::/64.
         self.nodes[BR].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[BR].get_state(), 'router')
         self.nodes[BR].add_prefix('2002::/64', 'paros')
         self.nodes[BR].register_netdata()
@@ -194,7 +194,7 @@ class Cert_5_2_5_AddressQuery(thread_cert.TestCase):
             if i == BR:
                 continue
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[MED].start()
@@ -203,7 +203,7 @@ class Cert_5_2_5_AddressQuery(thread_cert.TestCase):
 
         # 4. Bring up DUT_REED.
         self.nodes[DUT_REED].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.simulator.go(ROUTER_SELECTION_JITTER)
 
         # 5. Enable a link between the DUT and BR to create a one-way link.
diff --git a/tests/scripts/thread-cert/Cert_5_2_06_RouterDowngrade.py b/tests/scripts/thread-cert/Cert_5_2_06_RouterDowngrade.py
index 32bf0386a..fdf33bf9d 100755
--- a/tests/scripts/thread-cert/Cert_5_2_06_RouterDowngrade.py
+++ b/tests/scripts/thread-cert/Cert_5_2_06_RouterDowngrade.py
@@ -216,7 +216,7 @@ class Cert_5_2_06_RouterDowngrade(thread_cert.TestCase):
 
         for i in range(2, 24):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
         self.collect_rloc16s()
 
@@ -224,7 +224,7 @@ class Cert_5_2_06_RouterDowngrade(thread_cert.TestCase):
         # so we don't need to ensure ROUTER23 has a better link quality on
         # posix.
         self.nodes[ROUTER23].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER23].get_state(), 'router')
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/Cert_5_2_07_REEDSynchronization.py b/tests/scripts/thread-cert/Cert_5_2_07_REEDSynchronization.py
index bc1a251be..930f0aa62 100755
--- a/tests/scripts/thread-cert/Cert_5_2_07_REEDSynchronization.py
+++ b/tests/scripts/thread-cert/Cert_5_2_07_REEDSynchronization.py
@@ -151,7 +151,7 @@ class Cert_5_2_7_REEDSynchronization_Base(thread_cert.TestCase):
 
         for i in range(2, 17):
             self.nodes[i].start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         for i in range(2, 17):
             self.assertEqual(self.nodes[i].get_state(), 'router')
diff --git a/tests/scripts/thread-cert/Cert_5_3_01_LinkLocal.py b/tests/scripts/thread-cert/Cert_5_3_01_LinkLocal.py
index dc0b7ca3c..74b03189b 100755
--- a/tests/scripts/thread-cert/Cert_5_3_01_LinkLocal.py
+++ b/tests/scripts/thread-cert/Cert_5_3_01_LinkLocal.py
@@ -75,7 +75,7 @@ class Cert_5_3_1_LinkLocal(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[DUT_ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER1].get_state(), 'router')
 
         self.collect_rlocs()
diff --git a/tests/scripts/thread-cert/Cert_5_3_02_RealmLocal.py b/tests/scripts/thread-cert/Cert_5_3_02_RealmLocal.py
index 9ff9bfd1a..2d7a42f51 100755
--- a/tests/scripts/thread-cert/Cert_5_3_02_RealmLocal.py
+++ b/tests/scripts/thread-cert/Cert_5_3_02_RealmLocal.py
@@ -93,11 +93,11 @@ class Cert_5_3_2_RealmLocal(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[DUT_ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER2].get_state(), 'router')
 
         self.nodes[SED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_3_03_AddressQuery.py b/tests/scripts/thread-cert/Cert_5_3_03_AddressQuery.py
index 2490e9a9f..3e66f2c80 100755
--- a/tests/scripts/thread-cert/Cert_5_3_03_AddressQuery.py
+++ b/tests/scripts/thread-cert/Cert_5_3_03_AddressQuery.py
@@ -103,7 +103,7 @@ class Cert_5_3_3_AddressQuery(thread_cert.TestCase):
         self.nodes[DUT_ROUTER2].start()
         self.nodes[ROUTER3].start()
         self.nodes[MED1].start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
         self.assertEqual(self.nodes[DUT_ROUTER2].get_state(), 'router')
diff --git a/tests/scripts/thread-cert/Cert_5_3_04_AddressMapCache.py b/tests/scripts/thread-cert/Cert_5_3_04_AddressMapCache.py
index 06a81e733..1e032e890 100755
--- a/tests/scripts/thread-cert/Cert_5_3_04_AddressMapCache.py
+++ b/tests/scripts/thread-cert/Cert_5_3_04_AddressMapCache.py
@@ -117,7 +117,7 @@ class Cert_5_3_4_AddressMapCache(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[DUT_ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER1].get_state(), 'router')
 
         for i in MTDS:
diff --git a/tests/scripts/thread-cert/Cert_5_3_05_RoutingLinkQuality.py b/tests/scripts/thread-cert/Cert_5_3_05_RoutingLinkQuality.py
index 5cb8d7e67..5dd4ac158 100755
--- a/tests/scripts/thread-cert/Cert_5_3_05_RoutingLinkQuality.py
+++ b/tests/scripts/thread-cert/Cert_5_3_05_RoutingLinkQuality.py
@@ -91,7 +91,7 @@ class Cert_5_3_5_RoutingLinkQuality(thread_cert.TestCase):
 
         for router in range(DUT_ROUTER1, ROUTER3 + 1):
             self.nodes[router].start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         for router in range(DUT_ROUTER1, ROUTER3 + 1):
             self.assertEqual(self.nodes[router].get_state(), 'router')
diff --git a/tests/scripts/thread-cert/Cert_5_3_06_RouterIdMask.py b/tests/scripts/thread-cert/Cert_5_3_06_RouterIdMask.py
index 71ecf8275..b7a21d3d8 100755
--- a/tests/scripts/thread-cert/Cert_5_3_06_RouterIdMask.py
+++ b/tests/scripts/thread-cert/Cert_5_3_06_RouterIdMask.py
@@ -90,11 +90,11 @@ class Cert_5_3_6_RouterIdMask(thread_cert.TestCase):
         self.assertEqual(self.nodes[DUT_LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.collect_rloc16s()
@@ -114,7 +114,7 @@ class Cert_5_3_6_RouterIdMask(thread_cert.TestCase):
         # 5
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.simulator.go(config.MAX_ADVERTISEMENT_INTERVAL)
diff --git a/tests/scripts/thread-cert/Cert_5_3_08_ChildAddressSet.py b/tests/scripts/thread-cert/Cert_5_3_08_ChildAddressSet.py
index 4f7fe00f6..8a2e0da39 100755
--- a/tests/scripts/thread-cert/Cert_5_3_08_ChildAddressSet.py
+++ b/tests/scripts/thread-cert/Cert_5_3_08_ChildAddressSet.py
@@ -100,7 +100,7 @@ class Cert_5_3_8_ChildAddressSet(thread_cert.TestCase):
         self.assertEqual(self.nodes[DUT_LEADER].get_state(), 'leader')
 
         self.nodes[BR].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[BR].get_state(), 'router')
 
         # 1 BR: Configure BR to be a DHCPv6 server
diff --git a/tests/scripts/thread-cert/Cert_5_3_09_AddressQuery.py b/tests/scripts/thread-cert/Cert_5_3_09_AddressQuery.py
index 1f51345dc..ddbf8ee7b 100755
--- a/tests/scripts/thread-cert/Cert_5_3_09_AddressQuery.py
+++ b/tests/scripts/thread-cert/Cert_5_3_09_AddressQuery.py
@@ -118,15 +118,15 @@ class Cert_5_3_09_AddressQuery(thread_cert.TestCase):
         self.nodes[LEADER].register_netdata()
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[DUT_ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER3].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER3].get_state(), 'router')
 
         self.nodes[SED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_3_10_AddressQuery.py b/tests/scripts/thread-cert/Cert_5_3_10_AddressQuery.py
index 8c3b1642e..4781f6058 100755
--- a/tests/scripts/thread-cert/Cert_5_3_10_AddressQuery.py
+++ b/tests/scripts/thread-cert/Cert_5_3_10_AddressQuery.py
@@ -113,7 +113,7 @@ class Cert_5_3_10_AddressQuery(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[BR].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[BR].get_state(), 'router')
 
         # Configure two On-Mesh Prefixes on the BR
@@ -122,11 +122,11 @@ class Cert_5_3_10_AddressQuery(thread_cert.TestCase):
         self.nodes[BR].register_netdata()
 
         self.nodes[DUT_ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[MED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_3_11_AddressQueryTimeoutIntervals.py b/tests/scripts/thread-cert/Cert_5_3_11_AddressQueryTimeoutIntervals.py
index a7f0fec8b..51e78b1e2 100755
--- a/tests/scripts/thread-cert/Cert_5_3_11_AddressQueryTimeoutIntervals.py
+++ b/tests/scripts/thread-cert/Cert_5_3_11_AddressQueryTimeoutIntervals.py
@@ -89,7 +89,7 @@ class Cert_5_3_11_AddressQueryTimeoutIntervals(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[DUT_ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER1].get_state(), 'router')
 
         self.nodes[MED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_5_01_LeaderReboot.py b/tests/scripts/thread-cert/Cert_5_5_01_LeaderReboot.py
index 70239e0f6..1ebebae99 100755
--- a/tests/scripts/thread-cert/Cert_5_5_01_LeaderReboot.py
+++ b/tests/scripts/thread-cert/Cert_5_5_01_LeaderReboot.py
@@ -83,7 +83,7 @@ class Cert_5_5_1_LeaderReboot(thread_cert.TestCase):
         self.assertEqual(self.nodes[DUT_LEADER].get_state(), 'leader')
 
         self.nodes[DUT_ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[DUT_ROUTER1].get_state(), 'router')
 
         leader_rloc = self.nodes[DUT_LEADER].get_ip6_address(config.ADDRESS_TYPE.RLOC)
diff --git a/tests/scripts/thread-cert/Cert_5_5_02_LeaderReboot.py b/tests/scripts/thread-cert/Cert_5_5_02_LeaderReboot.py
index 5c0f95ea5..be94103f6 100755
--- a/tests/scripts/thread-cert/Cert_5_5_02_LeaderReboot.py
+++ b/tests/scripts/thread-cert/Cert_5_5_02_LeaderReboot.py
@@ -71,7 +71,7 @@ class Cert_5_5_2_LeaderReboot(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED].start()
@@ -84,7 +84,7 @@ class Cert_5_5_2_LeaderReboot(thread_cert.TestCase):
         self.assertEqual(self.nodes[ROUTER].get_state(), 'leader')
 
         self.nodes[LEADER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[LEADER].get_state(), 'router')
 
         addrs = self.nodes[ED].get_addrs()
diff --git a/tests/scripts/thread-cert/Cert_5_5_03_SplitMergeChildren.py b/tests/scripts/thread-cert/Cert_5_5_03_SplitMergeChildren.py
index d316b3726..7a1d02f40 100755
--- a/tests/scripts/thread-cert/Cert_5_5_03_SplitMergeChildren.py
+++ b/tests/scripts/thread-cert/Cert_5_5_03_SplitMergeChildren.py
@@ -89,11 +89,11 @@ class Cert_5_5_3_SplitMergeChildren(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ED2].start()
@@ -114,7 +114,7 @@ class Cert_5_5_3_SplitMergeChildren(thread_cert.TestCase):
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'leader')
 
         self.nodes[LEADER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[LEADER].get_state(), 'router')
 
         self.simulator.go(30)
diff --git a/tests/scripts/thread-cert/Cert_5_5_04_SplitMergeRouters.py b/tests/scripts/thread-cert/Cert_5_5_04_SplitMergeRouters.py
index 1473ac429..7628e961a 100755
--- a/tests/scripts/thread-cert/Cert_5_5_04_SplitMergeRouters.py
+++ b/tests/scripts/thread-cert/Cert_5_5_04_SplitMergeRouters.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_CHILD_ID_RESPONSE, SOURCE_ADDRESS_TLV, ROUTE64_TLV, LEADER_DATA_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -81,19 +82,19 @@ class Cert_5_5_4_SplitMergeRouters(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER3].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER3].get_state(), 'router')
 
         self.nodes[ROUTER4].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER4].get_state(), 'router')
 
         self.nodes[LEADER].reset()
diff --git a/tests/scripts/thread-cert/Cert_5_5_05_SplitMergeREED.py b/tests/scripts/thread-cert/Cert_5_5_05_SplitMergeREED.py
index 154b069f0..89492c73b 100755
--- a/tests/scripts/thread-cert/Cert_5_5_05_SplitMergeREED.py
+++ b/tests/scripts/thread-cert/Cert_5_5_05_SplitMergeREED.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_LINK_REQUEST, MLE_PARENT_REQUEST, MLE_PARENT_RESPONSE, MLE_CHILD_ID_REQUEST, MLE_CHILD_ID_RESPONSE, ADDR_SOL_URI, VERSION_TLV, TLV_REQUEST_TLV, SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, CHALLENGE_TLV, LINK_MARGIN_TLV, NL_MAC_EXTENDED_ADDRESS_TLV, NL_STATUS_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -125,11 +126,11 @@ class Cert_5_5_5_SplitMergeREED(thread_cert.TestCase):
 
         for i in range(ROUTER2, ROUTER15 + 1):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[REED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_5_07_SplitMergeThreeWay.py b/tests/scripts/thread-cert/Cert_5_5_07_SplitMergeThreeWay.py
index df8f2e523..16be6ab21 100755
--- a/tests/scripts/thread-cert/Cert_5_5_07_SplitMergeThreeWay.py
+++ b/tests/scripts/thread-cert/Cert_5_5_07_SplitMergeThreeWay.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_PARENT_RESPONSE, MLE_CHILD_ID_REQUEST, MLE_CHILD_ID_RESPONSE, SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, ROUTE64_TLV, MODE_TLV, CHALLENGE_TLV, SCAN_MASK_TLV, VERSION_TLV, LINK_LAYER_FRAME_COUNTER_TLV, RESPONSE_TLV, LINK_MARGIN_TLV, CONNECTIVITY_TLV, TIMEOUT_TLV, TLV_REQUEST_TLV, ADDRESS16_TLV, NETWORK_DATA_TLV, ACTIVE_TIMESTAMP_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -76,15 +77,15 @@ class Cert_5_5_7_SplitMergeThreeWay(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER1].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER3].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER3].get_state(), 'router')
 
         self.nodes[LEADER1].reset()
diff --git a/tests/scripts/thread-cert/Cert_5_6_01_NetworkDataRegisterBeforeAttachLeader.py b/tests/scripts/thread-cert/Cert_5_6_01_NetworkDataRegisterBeforeAttachLeader.py
index a76bac5cc..f98b45078 100755
--- a/tests/scripts/thread-cert/Cert_5_6_01_NetworkDataRegisterBeforeAttachLeader.py
+++ b/tests/scripts/thread-cert/Cert_5_6_01_NetworkDataRegisterBeforeAttachLeader.py
@@ -86,7 +86,7 @@ class Cert_5_6_1_NetworkDataLeaderAsBr(thread_cert.TestCase):
         self.simulator.go(5)
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_6_02_NetworkDataRegisterBeforeAttachRouter.py b/tests/scripts/thread-cert/Cert_5_6_02_NetworkDataRegisterBeforeAttachRouter.py
index 283627925..d3c6089fe 100755
--- a/tests/scripts/thread-cert/Cert_5_6_02_NetworkDataRegisterBeforeAttachRouter.py
+++ b/tests/scripts/thread-cert/Cert_5_6_02_NetworkDataRegisterBeforeAttachRouter.py
@@ -76,7 +76,7 @@ class Cert_5_6_2_NetworkDataRouterAsBr(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ROUTER].add_prefix('2001:2:0:1::/64', 'paros')
diff --git a/tests/scripts/thread-cert/Cert_5_6_03_NetworkDataRegisterAfterAttachLeader.py b/tests/scripts/thread-cert/Cert_5_6_03_NetworkDataRegisterAfterAttachLeader.py
index ea331cee9..9c0335c2e 100755
--- a/tests/scripts/thread-cert/Cert_5_6_03_NetworkDataRegisterAfterAttachLeader.py
+++ b/tests/scripts/thread-cert/Cert_5_6_03_NetworkDataRegisterAfterAttachLeader.py
@@ -76,7 +76,7 @@ class Cert_5_6_3_NetworkDataRegisterAfterAttachLeader(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_6_04_NetworkDataRegisterAfterAttachRouter.py b/tests/scripts/thread-cert/Cert_5_6_04_NetworkDataRegisterAfterAttachRouter.py
index ef32030e3..858d291c5 100755
--- a/tests/scripts/thread-cert/Cert_5_6_04_NetworkDataRegisterAfterAttachRouter.py
+++ b/tests/scripts/thread-cert/Cert_5_6_04_NetworkDataRegisterAfterAttachRouter.py
@@ -76,7 +76,7 @@ class Cert_5_6_4_NetworkDataRegisterAfterAttachRouter(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py b/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py
index ad395ddf1..58f162ed2 100755
--- a/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py
+++ b/tests/scripts/thread-cert/Cert_5_6_05_NetworkDataRegisterAfterAttachRouter.py
@@ -76,7 +76,7 @@ class Cert_5_6_5_NetworkDataRegisterAfterAttachRouter(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py b/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
index d1b256465..df02a2f15 100755
--- a/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
+++ b/tests/scripts/thread-cert/Cert_5_6_06_NetworkDataExpiration.py
@@ -76,7 +76,7 @@ class Cert_5_6_6_NetworkDataExpiration(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_6_07_NetworkDataRequestREED.py b/tests/scripts/thread-cert/Cert_5_6_07_NetworkDataRequestREED.py
index 2e51c791f..fe7536b7e 100755
--- a/tests/scripts/thread-cert/Cert_5_6_07_NetworkDataRequestREED.py
+++ b/tests/scripts/thread-cert/Cert_5_6_07_NetworkDataRequestREED.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_CHILD_ID_RESPONSE, MLE_DATA_REQUEST, MLE_DATA_RESPONSE, TLV_REQUEST_TLV, NETWORK_DATA_TLV, SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, NWD_PREFIX_TLV, NWD_BORDER_ROUTER_TLV, NWD_6LOWPAN_ID_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -124,7 +125,7 @@ class Cert_5_6_7_NetworkDataRequestREED(thread_cert.TestCase):
 
         for i in range(ROUTER1, ROUTER15 + 1):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[REED1].start()
diff --git a/tests/scripts/thread-cert/Cert_5_6_09_NetworkDataForwarding.py b/tests/scripts/thread-cert/Cert_5_6_09_NetworkDataForwarding.py
index 224b06ec7..0397dcc85 100755
--- a/tests/scripts/thread-cert/Cert_5_6_09_NetworkDataForwarding.py
+++ b/tests/scripts/thread-cert/Cert_5_6_09_NetworkDataForwarding.py
@@ -82,11 +82,11 @@ class Cert_5_6_9_NetworkDataForwarding(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ED].start()
diff --git a/tests/scripts/thread-cert/Cert_5_7_01_CoapDiagCommands.py b/tests/scripts/thread-cert/Cert_5_7_01_CoapDiagCommands.py
index 0fd6ddcf4..c5bb0f2c0 100755
--- a/tests/scripts/thread-cert/Cert_5_7_01_CoapDiagCommands.py
+++ b/tests/scripts/thread-cert/Cert_5_7_01_CoapDiagCommands.py
@@ -114,7 +114,7 @@ class Cert_5_7_01_CoapDiagCommands_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         for i in range(3, 7):
diff --git a/tests/scripts/thread-cert/Cert_5_7_02_CoapDiagCommands.py b/tests/scripts/thread-cert/Cert_5_7_02_CoapDiagCommands.py
index ee8005035..f9f8a4143 100755
--- a/tests/scripts/thread-cert/Cert_5_7_02_CoapDiagCommands.py
+++ b/tests/scripts/thread-cert/Cert_5_7_02_CoapDiagCommands.py
@@ -164,7 +164,7 @@ class Cert_5_7_02_CoapDiagCommands(thread_cert.TestCase):
 
         for i in range(2, 17):
             self.nodes[i].start()
-            self.simulator.go(10)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[REED].start()
diff --git a/tests/scripts/thread-cert/Cert_5_7_03_CoapDiagCommands.py b/tests/scripts/thread-cert/Cert_5_7_03_CoapDiagCommands.py
index 1b4e7a245..e33da6872 100755
--- a/tests/scripts/thread-cert/Cert_5_7_03_CoapDiagCommands.py
+++ b/tests/scripts/thread-cert/Cert_5_7_03_CoapDiagCommands.py
@@ -108,7 +108,7 @@ class Cert_5_7_03_CoapDiagCommands_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         for i in range(3, 6):
diff --git a/tests/scripts/thread-cert/Cert_5_8_02_KeyIncrement.py b/tests/scripts/thread-cert/Cert_5_8_02_KeyIncrement.py
index 967a33a20..cead10f48 100755
--- a/tests/scripts/thread-cert/Cert_5_8_02_KeyIncrement.py
+++ b/tests/scripts/thread-cert/Cert_5_8_02_KeyIncrement.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_CHILD_ID_RESPONSE
 from pktverify.packet_verifier import PacketVerifier
@@ -59,7 +60,7 @@ class Cert_5_8_2_KeyIncrement(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), "leader")
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), "router")
 
         self.collect_ipaddrs()
diff --git a/tests/scripts/thread-cert/Cert_5_8_03_KeyIncrementRollOver.py b/tests/scripts/thread-cert/Cert_5_8_03_KeyIncrementRollOver.py
index 3bb6e72a3..4dc9919bc 100755
--- a/tests/scripts/thread-cert/Cert_5_8_03_KeyIncrementRollOver.py
+++ b/tests/scripts/thread-cert/Cert_5_8_03_KeyIncrementRollOver.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_CHILD_ID_RESPONSE
 from pktverify.packet_verifier import PacketVerifier
@@ -60,7 +61,7 @@ class Cert_5_8_3_KeyIncrementRollOver(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.collect_ipaddrs()
diff --git a/tests/scripts/thread-cert/Cert_5_8_04_SecurityPolicyTLV.py b/tests/scripts/thread-cert/Cert_5_8_04_SecurityPolicyTLV.py
index 28dc68c92..1fc93e6b7 100755
--- a/tests/scripts/thread-cert/Cert_5_8_04_SecurityPolicyTLV.py
+++ b/tests/scripts/thread-cert/Cert_5_8_04_SecurityPolicyTLV.py
@@ -30,6 +30,7 @@
 import unittest
 
 from mesh_cop import TlvType
+import config
 import thread_cert
 from pktverify.consts import MLE_DATA_RESPONSE, MGMT_ACTIVE_SET_URI, MGMT_ACTIVE_GET_URI, LEADER_ALOC, NM_COMMISSIONER_SESSION_ID_TLV, NM_ACTIVE_TIMESTAMP_TLV, NM_SECURITY_POLICY_TLV, NM_NETWORK_KEY_TLV, MLE_DISCOVERY_RESPONSE
 from pktverify.packet_verifier import PacketVerifier
@@ -115,7 +116,7 @@ class Cert_5_8_04_SecurityPolicyTLV(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER_1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER_1].get_state(), 'router')
 
         self.nodes[COMMISSIONER_1].commissioner_start()
diff --git a/tests/scripts/thread-cert/Cert_6_1_03_RouterAttachConnectivity.py b/tests/scripts/thread-cert/Cert_6_1_03_RouterAttachConnectivity.py
index e5d2dce19..da91d6333 100755
--- a/tests/scripts/thread-cert/Cert_6_1_03_RouterAttachConnectivity.py
+++ b/tests/scripts/thread-cert/Cert_6_1_03_RouterAttachConnectivity.py
@@ -79,7 +79,7 @@ class Cert_6_1_3_RouterAttachConnectivity(thread_cert.TestCase):
         for i in range(2, 5):
             self.nodes[i].start()
 
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         for i in range(2, 5):
             self.assertEqual(self.nodes[i].get_state(), 'router')
diff --git a/tests/scripts/thread-cert/Cert_6_1_04_REEDAttachConnectivity.py b/tests/scripts/thread-cert/Cert_6_1_04_REEDAttachConnectivity.py
index a073cde7e..8c05eaa0f 100755
--- a/tests/scripts/thread-cert/Cert_6_1_04_REEDAttachConnectivity.py
+++ b/tests/scripts/thread-cert/Cert_6_1_04_REEDAttachConnectivity.py
@@ -100,7 +100,7 @@ class Cert_6_1_4_REEDAttachConnectivity_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         for i in (3, 4):
diff --git a/tests/scripts/thread-cert/Cert_6_1_05_REEDAttachConnectivity.py b/tests/scripts/thread-cert/Cert_6_1_05_REEDAttachConnectivity.py
index 7264fb1d0..b6513798b 100755
--- a/tests/scripts/thread-cert/Cert_6_1_05_REEDAttachConnectivity.py
+++ b/tests/scripts/thread-cert/Cert_6_1_05_REEDAttachConnectivity.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_REQUEST, MLE_PARENT_REQUEST, MODE_TLV, CHALLENGE_TLV, SCAN_MASK_TLV, VERSION_TLV, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, MLE_FRAME_COUNTER_TLV, TIMEOUT_TLV, ADDRESS_REGISTRATION_TLV, TLV_REQUEST_TLV, LINK_LOCAL_ALL_ROUTERS_MULTICAST_ADDRESS
 from pktverify.packet_verifier import PacketVerifier
@@ -78,7 +79,7 @@ class Cert_6_1_5_REEDAttachConnectivity(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[REED1].start()
diff --git a/tests/scripts/thread-cert/Cert_6_1_06_REEDAttachLinkQuality.py b/tests/scripts/thread-cert/Cert_6_1_06_REEDAttachLinkQuality.py
index 73b897ad1..296ddf71f 100755
--- a/tests/scripts/thread-cert/Cert_6_1_06_REEDAttachLinkQuality.py
+++ b/tests/scripts/thread-cert/Cert_6_1_06_REEDAttachLinkQuality.py
@@ -99,7 +99,7 @@ class Cert_6_1_6_REEDAttachLinkQuality_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[REED].get_state(), 'child')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MTD].start()
diff --git a/tests/scripts/thread-cert/Cert_6_1_07_RouterAttachLinkQuality.py b/tests/scripts/thread-cert/Cert_6_1_07_RouterAttachLinkQuality.py
index 75a7aed27..0fd3ffb67 100755
--- a/tests/scripts/thread-cert/Cert_6_1_07_RouterAttachLinkQuality.py
+++ b/tests/scripts/thread-cert/Cert_6_1_07_RouterAttachLinkQuality.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_REQUEST, MLE_PARENT_REQUEST, MODE_TLV, CHALLENGE_TLV, SCAN_MASK_TLV, VERSION_TLV, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, MLE_FRAME_COUNTER_TLV, TIMEOUT_TLV, ADDRESS_REGISTRATION_TLV, TLV_REQUEST_TLV, LINK_LOCAL_ALL_ROUTERS_MULTICAST_ADDRESS
 from pktverify.packet_verifier import PacketVerifier
@@ -70,11 +71,11 @@ class Cert_6_1_7_RouterAttachLinkQuality(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ED].start()
diff --git a/tests/scripts/thread-cert/Cert_6_2_01_NewPartition.py b/tests/scripts/thread-cert/Cert_6_2_01_NewPartition.py
index 03d36d7f8..95ad479c6 100755
--- a/tests/scripts/thread-cert/Cert_6_2_01_NewPartition.py
+++ b/tests/scripts/thread-cert/Cert_6_2_01_NewPartition.py
@@ -87,7 +87,7 @@ class Cert_6_2_1_NewPartition_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[MTD].start()
diff --git a/tests/scripts/thread-cert/Cert_6_2_02_NewPartition.py b/tests/scripts/thread-cert/Cert_6_2_02_NewPartition.py
index 5be9b7b9e..071108205 100755
--- a/tests/scripts/thread-cert/Cert_6_2_02_NewPartition.py
+++ b/tests/scripts/thread-cert/Cert_6_2_02_NewPartition.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_REQUEST, MLE_ADVERTISEMENT, MLE_CHILD_UPDATE_REQUEST, SOURCE_ADDRESS_TLV, MODE_TLV, LEADER_DATA_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -71,11 +72,11 @@ class Cert_6_2_2_NewPartition(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ED].start()
diff --git a/tests/scripts/thread-cert/Cert_6_3_01_OrphanReattach.py b/tests/scripts/thread-cert/Cert_6_3_01_OrphanReattach.py
index fd4887e87..9f515e615 100755
--- a/tests/scripts/thread-cert/Cert_6_3_01_OrphanReattach.py
+++ b/tests/scripts/thread-cert/Cert_6_3_01_OrphanReattach.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_PARENT_REQUEST, MLE_CHILD_ID_REQUEST, MLE_CHILD_UPDATE_REQUEST, SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, MODE_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -65,7 +66,7 @@ class Cert_6_3_1_OrphanReattach(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED].start()
diff --git a/tests/scripts/thread-cert/Cert_6_3_02_NetworkDataUpdate.py b/tests/scripts/thread-cert/Cert_6_3_02_NetworkDataUpdate.py
index db0badb74..ac6a01feb 100755
--- a/tests/scripts/thread-cert/Cert_6_3_02_NetworkDataUpdate.py
+++ b/tests/scripts/thread-cert/Cert_6_3_02_NetworkDataUpdate.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_RESPONSE, MLE_DATA_REQUEST, MLE_CHILD_UPDATE_REQUEST, LEADER_DATA_TLV, ADDRESS_REGISTRATION_TLV, MODE_TLV, TIMEOUT_TLV, TLV_REQUEST_TLV, NETWORK_DATA_TLV
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_6_4_02_RealmLocal.py b/tests/scripts/thread-cert/Cert_6_4_02_RealmLocal.py
index e7a47ad8e..41a14d7dd 100755
--- a/tests/scripts/thread-cert/Cert_6_4_02_RealmLocal.py
+++ b/tests/scripts/thread-cert/Cert_6_4_02_RealmLocal.py
@@ -84,7 +84,7 @@ class Cert_6_4_2_RealmLocal_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MTD].start()
diff --git a/tests/scripts/thread-cert/Cert_6_5_01_ChildResetReattach.py b/tests/scripts/thread-cert/Cert_6_5_01_ChildResetReattach.py
index 12a455962..fdb970846 100755
--- a/tests/scripts/thread-cert/Cert_6_5_01_ChildResetReattach.py
+++ b/tests/scripts/thread-cert/Cert_6_5_01_ChildResetReattach.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_REQUEST, MLE_CHILD_UPDATE_REQUEST, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, MLE_FRAME_COUNTER_TLV, MODE_TLV, TIMEOUT_TLV, VERSION_TLV, ADDRESS_REGISTRATION_TLV, TLV_REQUEST_TLV
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_6_5_02_ChildResetReattach.py b/tests/scripts/thread-cert/Cert_6_5_02_ChildResetReattach.py
index 21ea2e1f7..99f1a45de 100755
--- a/tests/scripts/thread-cert/Cert_6_5_02_ChildResetReattach.py
+++ b/tests/scripts/thread-cert/Cert_6_5_02_ChildResetReattach.py
@@ -95,7 +95,7 @@ class Cert_6_5_2_ChildResetReattach_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MTD].start()
diff --git a/tests/scripts/thread-cert/Cert_6_6_01_KeyIncrement.py b/tests/scripts/thread-cert/Cert_6_6_01_KeyIncrement.py
index 33343a082..513af2ff0 100755
--- a/tests/scripts/thread-cert/Cert_6_6_01_KeyIncrement.py
+++ b/tests/scripts/thread-cert/Cert_6_6_01_KeyIncrement.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_CHILD_ID_REQUEST
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_6_6_02_KeyIncrementRollOver.py b/tests/scripts/thread-cert/Cert_6_6_02_KeyIncrementRollOver.py
index d6f8939d9..2a59fc3f2 100755
--- a/tests/scripts/thread-cert/Cert_6_6_02_KeyIncrementRollOver.py
+++ b/tests/scripts/thread-cert/Cert_6_6_02_KeyIncrementRollOver.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_CHILD_ID_REQUEST
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_7_1_01_BorderRouterAsLeader.py b/tests/scripts/thread-cert/Cert_7_1_01_BorderRouterAsLeader.py
index 83ee5db7d..c37eb4be9 100755
--- a/tests/scripts/thread-cert/Cert_7_1_01_BorderRouterAsLeader.py
+++ b/tests/scripts/thread-cert/Cert_7_1_01_BorderRouterAsLeader.py
@@ -106,7 +106,7 @@ class Cert_7_1_1_BorderRouterAsLeader(thread_cert.TestCase):
         self.nodes[LEADER].register_netdata()
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[SED1].start()
diff --git a/tests/scripts/thread-cert/Cert_7_1_02_BorderRouterAsRouter.py b/tests/scripts/thread-cert/Cert_7_1_02_BorderRouterAsRouter.py
index 58323afdb..a657fc665 100755
--- a/tests/scripts/thread-cert/Cert_7_1_02_BorderRouterAsRouter.py
+++ b/tests/scripts/thread-cert/Cert_7_1_02_BorderRouterAsRouter.py
@@ -76,7 +76,7 @@ class Cert_7_1_2_BorderRouterAsRouter(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ROUTER].add_prefix('2001:2:0:1::/64', 'paros')
diff --git a/tests/scripts/thread-cert/Cert_7_1_03_BorderRouterAsLeader.py b/tests/scripts/thread-cert/Cert_7_1_03_BorderRouterAsLeader.py
index c506d7c5e..94befdde6 100755
--- a/tests/scripts/thread-cert/Cert_7_1_03_BorderRouterAsLeader.py
+++ b/tests/scripts/thread-cert/Cert_7_1_03_BorderRouterAsLeader.py
@@ -103,7 +103,7 @@ class Cert_7_1_3_BorderRouterAsLeader(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[SED1].start()
diff --git a/tests/scripts/thread-cert/Cert_7_1_04_BorderRouterAsRouter.py b/tests/scripts/thread-cert/Cert_7_1_04_BorderRouterAsRouter.py
index 420fbffad..965e9b349 100755
--- a/tests/scripts/thread-cert/Cert_7_1_04_BorderRouterAsRouter.py
+++ b/tests/scripts/thread-cert/Cert_7_1_04_BorderRouterAsRouter.py
@@ -76,7 +76,7 @@ class Cert_7_1_4_BorderRouterAsRouter(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED2].start()
diff --git a/tests/scripts/thread-cert/Cert_7_1_05_BorderRouterAsRouter.py b/tests/scripts/thread-cert/Cert_7_1_05_BorderRouterAsRouter.py
index ea7b41162..6fd3c2d75 100755
--- a/tests/scripts/thread-cert/Cert_7_1_05_BorderRouterAsRouter.py
+++ b/tests/scripts/thread-cert/Cert_7_1_05_BorderRouterAsRouter.py
@@ -101,7 +101,7 @@ class Cert_7_1_5_BorderRouterAsRouter(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MED].start()
diff --git a/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py b/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py
index ad25b4fc6..0ec424a59 100755
--- a/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py
+++ b/tests/scripts/thread-cert/Cert_7_1_06_BorderRouterAsLeader.py
@@ -118,7 +118,7 @@ class Cert_7_1_6_BorderRouterAsLeader(thread_cert.TestCase):
 
         for i in (2, 3):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[MED].start()
@@ -143,7 +143,7 @@ class Cert_7_1_6_BorderRouterAsLeader(thread_cert.TestCase):
         self.simulator.go(720)
 
         self.nodes[ROUTER_1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER_1].get_state(), 'router')
         self.collect_rloc16s()
 
diff --git a/tests/scripts/thread-cert/Cert_7_1_07_BorderRouterAsLeader.py b/tests/scripts/thread-cert/Cert_7_1_07_BorderRouterAsLeader.py
index be980148e..95b2d4aee 100755
--- a/tests/scripts/thread-cert/Cert_7_1_07_BorderRouterAsLeader.py
+++ b/tests/scripts/thread-cert/Cert_7_1_07_BorderRouterAsLeader.py
@@ -118,7 +118,7 @@ class Cert_7_1_7_BorderRouterAsLeader(thread_cert.TestCase):
 
         for i in (2, 3):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[MED].start()
diff --git a/tests/scripts/thread-cert/Cert_7_1_08_BorderRouterAsFED.py b/tests/scripts/thread-cert/Cert_7_1_08_BorderRouterAsFED.py
index a885e6566..1e3c7df0d 100755
--- a/tests/scripts/thread-cert/Cert_7_1_08_BorderRouterAsFED.py
+++ b/tests/scripts/thread-cert/Cert_7_1_08_BorderRouterAsFED.py
@@ -96,7 +96,7 @@ class Cert_7_1_8_BorderRouterAsFED(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[FED].start()
diff --git a/tests/scripts/thread-cert/Cert_8_1_01_Commissioning.py b/tests/scripts/thread-cert/Cert_8_1_01_Commissioning.py
index 1862d70fe..b4104dae1 100755
--- a/tests/scripts/thread-cert/Cert_8_1_01_Commissioning.py
+++ b/tests/scripts/thread-cert/Cert_8_1_01_Commissioning.py
@@ -30,6 +30,7 @@
 import unittest
 
 import command
+import config
 import dtls
 import thread_cert
 from pktverify.consts import MLE_DISCOVERY_REQUEST, MLE_DISCOVERY_RESPONSE, HANDSHAKE_CLIENT_HELLO, HANDSHAKE_SERVER_HELLO, HANDSHAKE_SERVER_KEY_EXCHANGE, HANDSHAKE_SERVER_HELLO_DONE, HANDSHAKE_CLIENT_KEY_EXCHANGE, HANDSHAKE_HELLO_VERIFY_REQUEST, CONTENT_APPLICATION_DATA, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_STEERING_DATA_TLV, NM_COMMISSIONER_UDP_PORT_TLV, NM_JOINER_UDP_PORT_TLV, NM_DISCOVERY_REQUEST_TLV, NM_DISCOVERY_RESPONSE_TLV, THREAD_DISCOVERY_TLV, CONTENT_CHANGE_CIPHER_SPEC, CONTENT_HANDSHAKE, CONTENT_ALERT
diff --git a/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py b/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py
index ca3920552..f47fbef8d 100755
--- a/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py
+++ b/tests/scripts/thread-cert/Cert_8_1_02_Commissioning.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_DISCOVERY_RESPONSE, HANDSHAKE_CLIENT_HELLO, HANDSHAKE_SERVER_HELLO, HANDSHAKE_SERVER_KEY_EXCHANGE, HANDSHAKE_SERVER_HELLO_DONE, HANDSHAKE_CLIENT_KEY_EXCHANGE, HANDSHAKE_HELLO_VERIFY_REQUEST, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_STEERING_DATA_TLV, NM_COMMISSIONER_UDP_PORT_TLV, NM_JOINER_UDP_PORT_TLV, NM_DISCOVERY_RESPONSE_TLV, CONTENT_CHANGE_CIPHER_SPEC, CONTENT_ALERT, CONTENT_HANDSHAKE
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_8_1_06_Commissioning.py b/tests/scripts/thread-cert/Cert_8_1_06_Commissioning.py
index 249d590a1..667bea096 100755
--- a/tests/scripts/thread-cert/Cert_8_1_06_Commissioning.py
+++ b/tests/scripts/thread-cert/Cert_8_1_06_Commissioning.py
@@ -30,6 +30,7 @@
 import unittest
 
 import command
+import config
 from mesh_cop import MeshCopState
 import thread_cert
 from pktverify.consts import MLE_DISCOVERY_REQUEST, MLE_DISCOVERY_RESPONSE, HANDSHAKE_CLIENT_HELLO, HANDSHAKE_SERVER_HELLO, HANDSHAKE_SERVER_KEY_EXCHANGE, HANDSHAKE_SERVER_HELLO_DONE, HANDSHAKE_CLIENT_KEY_EXCHANGE, HANDSHAKE_HELLO_VERIFY_REQUEST, CONTENT_APPLICATION_DATA, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_STEERING_DATA_TLV, NM_COMMISSIONER_UDP_PORT_TLV, NM_JOINER_UDP_PORT_TLV, NM_DISCOVERY_REQUEST_TLV, NM_DISCOVERY_RESPONSE_TLV, THREAD_DISCOVERY_TLV, CONTENT_CHANGE_CIPHER_SPEC, CONTENT_HANDSHAKE, CONTENT_ALERT
diff --git a/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py b/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py
index a29f79d47..a9960be40 100755
--- a/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py
+++ b/tests/scripts/thread-cert/Cert_8_2_01_JoinerRouter.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_RESPONSE, MLE_DISCOVERY_RESPONSE, HANDSHAKE_CLIENT_HELLO, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_STEERING_DATA_TLV, NM_COMMISSIONER_UDP_PORT_TLV, NM_JOINER_UDP_PORT_TLV, NM_DISCOVERY_RESPONSE_TLV, RLY_RX_URI, RLY_TX_URI
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_8_2_02_JoinerRouter.py b/tests/scripts/thread-cert/Cert_8_2_02_JoinerRouter.py
index 8c6644416..8d651420b 100755
--- a/tests/scripts/thread-cert/Cert_8_2_02_JoinerRouter.py
+++ b/tests/scripts/thread-cert/Cert_8_2_02_JoinerRouter.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_RESPONSE, MLE_DISCOVERY_RESPONSE, HANDSHAKE_CLIENT_HELLO, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_STEERING_DATA_TLV, NM_COMMISSIONER_UDP_PORT_TLV, NM_JOINER_UDP_PORT_TLV, NM_DISCOVERY_RESPONSE_TLV, RLY_RX_URI, RLY_TX_URI
 from pktverify.packet_verifier import PacketVerifier
diff --git a/tests/scripts/thread-cert/Cert_8_2_05_JoinerRouter.py b/tests/scripts/thread-cert/Cert_8_2_05_JoinerRouter.py
index 7ef829cfd..a3357613c 100755
--- a/tests/scripts/thread-cert/Cert_8_2_05_JoinerRouter.py
+++ b/tests/scripts/thread-cert/Cert_8_2_05_JoinerRouter.py
@@ -30,6 +30,7 @@
 import unittest
 
 import command
+import config
 from mesh_cop import MeshCopState
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_RESPONSE, MLE_DISCOVERY_RESPONSE, HANDSHAKE_CLIENT_HELLO, HANDSHAKE_HELLO_VERIFY_REQUEST, HANDSHAKE_SERVER_HELLO, HANDSHAKE_SERVER_KEY_EXCHANGE, HANDSHAKE_SERVER_HELLO_DONE, HANDSHAKE_CLIENT_KEY_EXCHANGE, CONTENT_CHANGE_CIPHER_SPEC, CONTENT_HANDSHAKE, CONTENT_APPLICATION_DATA, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_STEERING_DATA_TLV, NM_COMMISSIONER_UDP_PORT_TLV, NM_JOINER_UDP_PORT_TLV, NM_DISCOVERY_RESPONSE_TLV, NM_JOINER_DTLS_ENCAPSULATION_TLV, NM_JOINER_UDP_PORT_TLV, NM_JOINER_IID_TLV, NM_JOINER_ROUTER_LOCATOR_TLV, NM_JOINER_ROUTER_KEK_TLV, RLY_RX_URI, RLY_TX_URI
diff --git a/tests/scripts/thread-cert/Cert_8_3_01_CommissionerPetition.py b/tests/scripts/thread-cert/Cert_8_3_01_CommissionerPetition.py
index 03b056456..f85627671 100755
--- a/tests/scripts/thread-cert/Cert_8_3_01_CommissionerPetition.py
+++ b/tests/scripts/thread-cert/Cert_8_3_01_CommissionerPetition.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_DATA_RESPONSE, LEAD_PET_URI, LEAD_KA_URI, MGMT_COMMISSIONER_SET_URI, NM_COMMISSIONER_ID_TLV, NM_COMMISSIONER_SESSION_ID_TLV, NM_STATE_TLV, NM_STEERING_DATA_TLV, NM_BORDER_AGENT_LOCATOR_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, ACTIVE_TIMESTAMP_TLV, SOURCE_ADDRESS_TLV, NWD_COMMISSIONING_DATA_TLV, MESHCOP_ACCEPT, MESHCOP_REJECT
 from pktverify.packet_verifier import PacketVerifier
@@ -80,7 +81,7 @@ class Cert_8_3_01_CommissionerPetition(thread_cert.TestCase):
         self.simulator.go(5)
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
 
         self.collect_rlocs()
diff --git a/tests/scripts/thread-cert/Cert_9_2_01_MGMTCommissionerGet.py b/tests/scripts/thread-cert/Cert_9_2_01_MGMTCommissionerGet.py
index a2ea7c0d1..56f8b5e27 100755
--- a/tests/scripts/thread-cert/Cert_9_2_01_MGMTCommissionerGet.py
+++ b/tests/scripts/thread-cert/Cert_9_2_01_MGMTCommissionerGet.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_DATA_RESPONSE, MGMT_COMMISSIONER_GET_URI, NM_CHANNEL_TLV, NM_COMMISSIONER_ID_TLV, NM_COMMISSIONER_SESSION_ID_TLV, NM_STEERING_DATA_TLV, NM_BORDER_AGENT_LOCATOR_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, ACTIVE_TIMESTAMP_TLV, SOURCE_ADDRESS_TLV, NWD_COMMISSIONING_DATA_TLV, NM_PAN_ID_TLV, NM_NETWORK_NAME_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -77,7 +78,7 @@ class Cert_9_2_01_MGMTCommissionerGet(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
 
         self.collect_leader_aloc(LEADER)
diff --git a/tests/scripts/thread-cert/Cert_9_2_02_MGMTCommissionerSet.py b/tests/scripts/thread-cert/Cert_9_2_02_MGMTCommissionerSet.py
index 9d35f3f0b..17f721112 100755
--- a/tests/scripts/thread-cert/Cert_9_2_02_MGMTCommissionerSet.py
+++ b/tests/scripts/thread-cert/Cert_9_2_02_MGMTCommissionerSet.py
@@ -30,6 +30,7 @@
 import unittest
 
 import command
+import config
 import mesh_cop
 import thread_cert
 from pktverify.consts import MLE_DATA_RESPONSE, LEAD_PET_URI, LEAD_KA_URI, MGMT_COMMISSIONER_SET_URI, NM_CHANNEL_TLV, NM_COMMISSIONER_ID_TLV, NM_COMMISSIONER_SESSION_ID_TLV, NM_STATE_TLV, NM_STEERING_DATA_TLV, NM_BORDER_AGENT_LOCATOR_TLV, LEADER_DATA_TLV, NETWORK_DATA_TLV, ACTIVE_TIMESTAMP_TLV, SOURCE_ADDRESS_TLV, NWD_COMMISSIONING_DATA_TLV, MESHCOP_ACCEPT, MESHCOP_REJECT, LEADER_ALOC
@@ -78,7 +79,7 @@ class Cert_9_2_02_MGMTCommissionerSet(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.simulator.get_messages_sent_by(LEADER)
 
diff --git a/tests/scripts/thread-cert/Cert_9_2_03_ActiveDatasetGet.py b/tests/scripts/thread-cert/Cert_9_2_03_ActiveDatasetGet.py
index b294f8951..0a8fed9f9 100755
--- a/tests/scripts/thread-cert/Cert_9_2_03_ActiveDatasetGet.py
+++ b/tests/scripts/thread-cert/Cert_9_2_03_ActiveDatasetGet.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mesh_cop
 import thread_cert
 from pktverify.consts import MLE_DATA_RESPONSE, MGMT_ACTIVE_GET_URI, NM_CHANNEL_TLV, NM_COMMISSIONER_ID_TLV, NM_COMMISSIONER_SESSION_ID_TLV, NM_STEERING_DATA_TLV, NM_BORDER_AGENT_LOCATOR_TLV, NM_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_NETWORK_MESH_LOCAL_PREFIX_TLV, NM_PSKC_TLV, NM_SCAN_DURATION, NM_ENERGY_LIST_TLV, NM_ACTIVE_TIMESTAMP_TLV, NM_CHANNEL_MASK_TLV, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_KEY_TLV, NM_SECURITY_POLICY_TLV, LEADER_ALOC
@@ -78,7 +79,7 @@ class Cert_9_2_03_ActiveDatasetGet(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
 
         self.collect_rlocs()
diff --git a/tests/scripts/thread-cert/Cert_9_2_04_ActiveDataset.py b/tests/scripts/thread-cert/Cert_9_2_04_ActiveDataset.py
index ed1033fc1..7f76b31f4 100755
--- a/tests/scripts/thread-cert/Cert_9_2_04_ActiveDataset.py
+++ b/tests/scripts/thread-cert/Cert_9_2_04_ActiveDataset.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_RESPONSE, MGMT_ACTIVE_SET_URI, MGMT_ACTIVE_GET_URI
 from pktverify.packet_verifier import PacketVerifier
@@ -68,7 +69,7 @@ class Cert_9_2_04_ActiveDataset(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
 
         self.nodes[COMMISSIONER].commissioner_start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_05_ActiveDataset.py b/tests/scripts/thread-cert/Cert_9_2_05_ActiveDataset.py
index d9af874d5..8629e2b7f 100755
--- a/tests/scripts/thread-cert/Cert_9_2_05_ActiveDataset.py
+++ b/tests/scripts/thread-cert/Cert_9_2_05_ActiveDataset.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_DATA_RESPONSE, MGMT_ACTIVE_SET_URI, NETWORK_DATA_TLV, SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, ACTIVE_TIMESTAMP_TLV, ACTIVE_OPERATION_DATASET_TLV, NM_CHANNEL_TLV, NM_CHANNEL_MASK_TLV, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_MESH_LOCAL_PREFIX_TLV, NM_NETWORK_KEY_TLV, NM_NETWORK_NAME_TLV, NM_PAN_ID_TLV, NM_PSKC_TLV, NM_SECURITY_POLICY_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -79,7 +80,7 @@ class Cert_9_2_05_ActiveDataset(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ROUTER].commissioner_start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_06_DatasetDissemination.py b/tests/scripts/thread-cert/Cert_9_2_06_DatasetDissemination.py
index 1656ea718..94819eb20 100755
--- a/tests/scripts/thread-cert/Cert_9_2_06_DatasetDissemination.py
+++ b/tests/scripts/thread-cert/Cert_9_2_06_DatasetDissemination.py
@@ -147,7 +147,7 @@ class Cert_9_2_06_DatasetDissemination(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.simulator.get_messages_sent_by(LEADER)
         self.nodes[COMMISSIONER].commissioner_start()
@@ -156,7 +156,7 @@ class Cert_9_2_06_DatasetDissemination(thread_cert.TestCase):
         leader_messages = self.simulator.get_messages_sent_by(LEADER)
         msg = leader_messages.next_coap_message('2.04', assert_enabled=True)
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MED].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_07_DelayTimer.py b/tests/scripts/thread-cert/Cert_9_2_07_DelayTimer.py
index d8f4dce19..508265ece 100755
--- a/tests/scripts/thread-cert/Cert_9_2_07_DelayTimer.py
+++ b/tests/scripts/thread-cert/Cert_9_2_07_DelayTimer.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_RESPONSE, MLE_DATA_RESPONSE, MGMT_PENDING_SET_URI, MGMT_ACTIVE_SET_URI, MGMT_DATASET_CHANGED_URI, COAP_CODE_ACK, ACTIVE_OPERATION_DATASET_TLV, ACTIVE_TIMESTAMP_TLV, PENDING_TIMESTAMP_TLV, NM_CHANNEL_TLV, NM_CHANNEL_MASK_TLV, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_KEY_TLV, NM_NETWORK_MESH_LOCAL_PREFIX_TLV, NM_NETWORK_NAME_TLV, NM_PAN_ID_TLV, NM_PSKC_TLV, NM_SECURITY_POLICY_TLV, SOURCE_ADDRESS_TLV, LEADER_DATA_TLV, ACTIVE_TIMESTAMP_TLV, NETWORK_DATA_TLV, NM_BORDER_AGENT_LOCATOR_TLV, NM_COMMISSIONER_SESSION_ID_TLV, NM_DELAY_TIMER_TLV, PENDING_OPERATION_DATASET_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -80,7 +81,7 @@ class Cert_9_2_7_DelayTimer(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
diff --git a/tests/scripts/thread-cert/Cert_9_2_08_PersistentDatasets.py b/tests/scripts/thread-cert/Cert_9_2_08_PersistentDatasets.py
index 489438804..97072b3c1 100755
--- a/tests/scripts/thread-cert/Cert_9_2_08_PersistentDatasets.py
+++ b/tests/scripts/thread-cert/Cert_9_2_08_PersistentDatasets.py
@@ -115,11 +115,11 @@ class Cert_9_2_8_PersistentDatasets_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
 
         self.nodes[DUT].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         if self.TOPOLOGY[DUT]['mode'] == 'rdn':
             self.assertEqual(self.nodes[DUT].get_state(), 'router')
         else:
@@ -156,7 +156,7 @@ class Cert_9_2_8_PersistentDatasets_Base(thread_cert.TestCase):
 
         self.assertEqual(self.nodes[DUT].get_panid(), PANID_INIT)
         self.assertEqual(self.nodes[DUT].get_channel(), CHANNEL_INIT)
-        self.simulator.go(30)
+        self.simulator.go(60)
 
         self.assertEqual(self.nodes[DUT].get_panid(), COMMISSIONER_PENDING_PANID)
         self.assertEqual(self.nodes[DUT].get_channel(), COMMISSIONER_PENDING_CHANNEL)
diff --git a/tests/scripts/thread-cert/Cert_9_2_09_PendingPartition.py b/tests/scripts/thread-cert/Cert_9_2_09_PendingPartition.py
index 3452891ef..209669cc3 100755
--- a/tests/scripts/thread-cert/Cert_9_2_09_PendingPartition.py
+++ b/tests/scripts/thread-cert/Cert_9_2_09_PendingPartition.py
@@ -135,17 +135,17 @@ class Cert_9_2_09_PendingPartition(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[COMMISSIONER].send_mgmt_pending_set(
diff --git a/tests/scripts/thread-cert/Cert_9_2_10_PendingPartition.py b/tests/scripts/thread-cert/Cert_9_2_10_PendingPartition.py
index 3479a9ba2..d158e554d 100755
--- a/tests/scripts/thread-cert/Cert_9_2_10_PendingPartition.py
+++ b/tests/scripts/thread-cert/Cert_9_2_10_PendingPartition.py
@@ -104,13 +104,13 @@ class Cert_9_2_10_PendingPartition(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_11_NetworkKey.py b/tests/scripts/thread-cert/Cert_9_2_11_NetworkKey.py
index 514f5b33d..776a87d62 100755
--- a/tests/scripts/thread-cert/Cert_9_2_11_NetworkKey.py
+++ b/tests/scripts/thread-cert/Cert_9_2_11_NetworkKey.py
@@ -139,13 +139,13 @@ class Cert_9_2_11_NetworkKey(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_12_Announce.py b/tests/scripts/thread-cert/Cert_9_2_12_Announce.py
index ec2d4f224..8034ece26 100755
--- a/tests/scripts/thread-cert/Cert_9_2_12_Announce.py
+++ b/tests/scripts/thread-cert/Cert_9_2_12_Announce.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_REQUEST, MLE_PARENT_REQUEST, MLE_CHILD_ID_RESPONSE, MLE_ANNOUNCE, CHANNEL_TLV, PAN_ID_TLV, ACTIVE_TIMESTAMP_TLV, LINK_LOCAL_ALL_NODES_MULTICAST_ADDRESS
 from pktverify.packet_verifier import PacketVerifier
@@ -99,7 +100,7 @@ class Cert_9_2_12_Announce(thread_cert.TestCase):
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[LEADER2].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_13_EnergyScan.py b/tests/scripts/thread-cert/Cert_9_2_13_EnergyScan.py
index 667610e37..20aa19b55 100755
--- a/tests/scripts/thread-cert/Cert_9_2_13_EnergyScan.py
+++ b/tests/scripts/thread-cert/Cert_9_2_13_EnergyScan.py
@@ -71,13 +71,13 @@ class Cert_9_2_13_EnergyScan_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(5)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ED].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_14_PanIdQuery.py b/tests/scripts/thread-cert/Cert_9_2_14_PanIdQuery.py
index bc2c0e074..237814dde 100755
--- a/tests/scripts/thread-cert/Cert_9_2_14_PanIdQuery.py
+++ b/tests/scripts/thread-cert/Cert_9_2_14_PanIdQuery.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_CHILD_ID_REQUEST, MGMT_PANID_QUERY, MGMT_PANID_CONFLICT, MGMT_ED_REPORT, NM_COMMISSIONER_SESSION_ID_TLV, NM_CHANNEL_MASK_TLV, NM_PAN_ID_TLV, REALM_LOCAL_All_THREAD_NODES_MULTICAST_ADDRESS
 from pktverify.packet_verifier import PacketVerifier
@@ -72,13 +73,13 @@ class Cert_9_2_14_PanIdQuery(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER1].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[LEADER2].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_15_PendingPartition.py b/tests/scripts/thread-cert/Cert_9_2_15_PendingPartition.py
index f73e99f6b..fd18667c2 100755
--- a/tests/scripts/thread-cert/Cert_9_2_15_PendingPartition.py
+++ b/tests/scripts/thread-cert/Cert_9_2_15_PendingPartition.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_CHILD_ID_RESPONSE, MLE_CHILD_ID_REQUEST, MGMT_ACTIVE_SET_URI, MGMT_ACTIVE_GET_URI, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, MODE_TLV, TIMEOUT_TLV, VERSION_TLV, TLV_REQUEST_TLV, CHALLENGE_TLV, SCAN_MASK_TLV, ADDRESS_REGISTRATION_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -102,13 +103,13 @@ class Cert_9_2_15_PendingPartition(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[COMMISSIONER].send_mgmt_pending_set(
@@ -120,7 +121,7 @@ class Cert_9_2_15_PendingPartition(thread_cert.TestCase):
         self.simulator.go(5)
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER2].reset()
@@ -137,7 +138,7 @@ class Cert_9_2_15_PendingPartition(thread_cert.TestCase):
         self.simulator.go(100)
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
         self.simulator.go(100)
 
diff --git a/tests/scripts/thread-cert/Cert_9_2_16_ActivePendingPartition.py b/tests/scripts/thread-cert/Cert_9_2_16_ActivePendingPartition.py
index d2044d571..c0f60569a 100755
--- a/tests/scripts/thread-cert/Cert_9_2_16_ActivePendingPartition.py
+++ b/tests/scripts/thread-cert/Cert_9_2_16_ActivePendingPartition.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 from pktverify.consts import MLE_ADVERTISEMENT, MLE_PARENT_REQUEST, MLE_CHILD_ID_RESPONSE, MLE_CHILD_ID_REQUEST, MGMT_ACTIVE_SET_URI, MGMT_ACTIVE_GET_URI, RESPONSE_TLV, LINK_LAYER_FRAME_COUNTER_TLV, MODE_TLV, TIMEOUT_TLV, VERSION_TLV, TLV_REQUEST_TLV, CHALLENGE_TLV, SCAN_MASK_TLV, ADDRESS_REGISTRATION_TLV
 from pktverify.packet_verifier import PacketVerifier
@@ -103,13 +104,13 @@ class Cert_9_2_16_ActivePendingPartition(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[COMMISSIONER].send_mgmt_pending_set(
@@ -121,7 +122,7 @@ class Cert_9_2_16_ActivePendingPartition(thread_cert.TestCase):
         self.simulator.go(5)
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.nodes[ROUTER2].reset()
@@ -141,7 +142,7 @@ class Cert_9_2_16_ActivePendingPartition(thread_cert.TestCase):
         self.simulator.go(100)
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.assertEqual(self.nodes[COMMISSIONER].get_network_name(), NETWORK_NAME_FINAL)
diff --git a/tests/scripts/thread-cert/Cert_9_2_18_RollBackActiveTimestamp.py b/tests/scripts/thread-cert/Cert_9_2_18_RollBackActiveTimestamp.py
index 8e7ba5442..f8996a52f 100755
--- a/tests/scripts/thread-cert/Cert_9_2_18_RollBackActiveTimestamp.py
+++ b/tests/scripts/thread-cert/Cert_9_2_18_RollBackActiveTimestamp.py
@@ -115,13 +115,13 @@ class Cert_9_2_18_RollBackActiveTimestamp(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.nodes[COMMISSIONER].commissioner_start()
         self.simulator.go(3)
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/Cert_9_2_19_PendingDatasetGet.py b/tests/scripts/thread-cert/Cert_9_2_19_PendingDatasetGet.py
index 0a1d79205..de2c0a937 100755
--- a/tests/scripts/thread-cert/Cert_9_2_19_PendingDatasetGet.py
+++ b/tests/scripts/thread-cert/Cert_9_2_19_PendingDatasetGet.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mesh_cop
 import thread_cert
 from pktverify.consts import MGMT_PENDING_GET_URI, MGMT_PENDING_SET_URI, NM_CHANNEL_TLV, NM_PAN_ID_TLV, NM_NETWORK_NAME_TLV, NM_NETWORK_MESH_LOCAL_PREFIX_TLV, NM_PSKC_TLV, NM_ACTIVE_TIMESTAMP_TLV, NM_CHANNEL_MASK_TLV, NM_EXTENDED_PAN_ID_TLV, NM_NETWORK_KEY_TLV, NM_SECURITY_POLICY_TLV, NM_PENDING_TIMESTAMP_TLV, NM_DELAY_TIMER_TLV, LEADER_ALOC
@@ -77,7 +78,7 @@ class Cert_9_2_19_PendingDatasetGet(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[COMMISSIONER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[COMMISSIONER].get_state(), 'router')
         self.simulator.get_messages_sent_by(LEADER)
 
diff --git a/tests/scripts/thread-cert/border_router/test_advertising_proxy.py b/tests/scripts/thread-cert/border_router/test_advertising_proxy.py
index 55b931d34..7516ec88f 100755
--- a/tests/scripts/thread-cert/border_router/test_advertising_proxy.py
+++ b/tests/scripts/thread-cert/border_router/test_advertising_proxy.py
@@ -90,7 +90,7 @@ class SingleHostAndService(thread_cert.TestCase):
         self.assertEqual(server.srp_server_get_state(), 'running')
 
         client.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', client.get_state())
 
         #
@@ -309,7 +309,7 @@ class SrpClientRemoveNonExistingHost(thread_cert.TestCase):
         self.assertEqual(server.srp_server_get_state(), 'running')
 
         client.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', client.get_state())
 
         # Immediately remove a non-existing host.
diff --git a/tests/scripts/thread-cert/border_router/test_dnssd_instance_name_with_space.py b/tests/scripts/thread-cert/border_router/test_dnssd_instance_name_with_space.py
index 1e3bbcb69..f0eefa281 100644
--- a/tests/scripts/thread-cert/border_router/test_dnssd_instance_name_with_space.py
+++ b/tests/scripts/thread-cert/border_router/test_dnssd_instance_name_with_space.py
@@ -95,12 +95,12 @@ class TestDnssdInstanceNameWithSpace(thread_cert.TestCase):
         server.srp_server_set_enabled(True)
 
         br2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', br2.get_state())
 
         client.start()
 
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', client.get_state())
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/border_router/test_dnssd_server.py b/tests/scripts/thread-cert/border_router/test_dnssd_server.py
index fcbae865a..be3b8bebd 100644
--- a/tests/scripts/thread-cert/border_router/test_dnssd_server.py
+++ b/tests/scripts/thread-cert/border_router/test_dnssd_server.py
@@ -100,11 +100,11 @@ class TestDnssdServerOnBr(thread_cert.TestCase):
 
         client1.start()
 
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', client1.get_state())
 
         client2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', client2.get_state())
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/border_router/test_external_route.py b/tests/scripts/thread-cert/border_router/test_external_route.py
index e06129a62..7ed71dcb9 100644
--- a/tests/scripts/thread-cert/border_router/test_external_route.py
+++ b/tests/scripts/thread-cert/border_router/test_external_route.py
@@ -97,7 +97,7 @@ class ExternalRoutes(thread_cert.TestCase):
         self.assertEqual('leader', br1.get_state())
 
         br2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', br2.get_state())
 
         router1.start()
diff --git a/tests/scripts/thread-cert/border_router/test_firewall.py b/tests/scripts/thread-cert/border_router/test_firewall.py
index 354a01022..84b00500f 100644
--- a/tests/scripts/thread-cert/border_router/test_firewall.py
+++ b/tests/scripts/thread-cert/border_router/test_firewall.py
@@ -86,7 +86,7 @@ class Firewall(thread_cert.TestCase):
 
         router1.start()
         host.start(start_radvd=True)
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router1.get_state())
 
         br1.set_domain_prefix(config.DOMAIN_PREFIX, 'prosD')
diff --git a/tests/scripts/thread-cert/border_router/test_manual_address.py b/tests/scripts/thread-cert/border_router/test_manual_address.py
index 327c32b7f..62edbaa33 100644
--- a/tests/scripts/thread-cert/border_router/test_manual_address.py
+++ b/tests/scripts/thread-cert/border_router/test_manual_address.py
@@ -28,6 +28,8 @@
 #
 
 import unittest
+
+import config
 import thread_cert
 
 # Test description:
@@ -74,7 +76,7 @@ class ManualAddressConfig(thread_cert.TestCase):
         self.assertTrue(br1.is_primary_backbone_router)
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router.get_state())
 
         # Add prefix
diff --git a/tests/scripts/thread-cert/border_router/test_mdns_restart.py b/tests/scripts/thread-cert/border_router/test_mdns_restart.py
index 41a9d864c..2ea86d02a 100755
--- a/tests/scripts/thread-cert/border_router/test_mdns_restart.py
+++ b/tests/scripts/thread-cert/border_router/test_mdns_restart.py
@@ -106,7 +106,7 @@ class MdnsRestart(thread_cert.TestCase):
         self.simulator.go(5)
 
         br2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', br2.get_state())
 
         ed1.start()
diff --git a/tests/scripts/thread-cert/border_router/test_multi_border_routers.py b/tests/scripts/thread-cert/border_router/test_multi_border_routers.py
index 0e122d187..73dc85f9c 100755
--- a/tests/scripts/thread-cert/border_router/test_multi_border_routers.py
+++ b/tests/scripts/thread-cert/border_router/test_multi_border_routers.py
@@ -106,17 +106,17 @@ class MultiBorderRouters(thread_cert.TestCase):
         self.assertEqual('leader', br1.get_state())
 
         router1.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router1.get_state())
 
         self.simulator.go(5)
 
         br2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', br2.get_state())
 
         router2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router2.get_state())
 
         #
diff --git a/tests/scripts/thread-cert/border_router/test_multi_thread_networks.py b/tests/scripts/thread-cert/border_router/test_multi_thread_networks.py
index ca7e382d9..c5ab786ac 100755
--- a/tests/scripts/thread-cert/border_router/test_multi_thread_networks.py
+++ b/tests/scripts/thread-cert/border_router/test_multi_thread_networks.py
@@ -97,7 +97,7 @@ class MultiThreadNetworks(thread_cert.TestCase):
         self.assertEqual('leader', br1.get_state())
 
         router1.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router1.get_state())
 
         br2.start()
@@ -105,7 +105,7 @@ class MultiThreadNetworks(thread_cert.TestCase):
         self.assertEqual('leader', br2.get_state())
 
         router2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router2.get_state())
 
         # Wait for network to stabilize
diff --git a/tests/scripts/thread-cert/border_router/test_nat64_multi_border_routers.py b/tests/scripts/thread-cert/border_router/test_nat64_multi_border_routers.py
index 64e5ac8c5..f139836f5 100644
--- a/tests/scripts/thread-cert/border_router/test_nat64_multi_border_routers.py
+++ b/tests/scripts/thread-cert/border_router/test_nat64_multi_border_routers.py
@@ -28,6 +28,7 @@
 #
 import unittest
 
+import config
 import thread_cert
 
 # Test description:
@@ -92,7 +93,7 @@ class Nat64MultiBorderRouter(thread_cert.TestCase):
         self.assertEqual('leader', br1.get_state())
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router.get_state())
 
         #
@@ -100,7 +101,7 @@ class Nat64MultiBorderRouter(thread_cert.TestCase):
         #         its local nat64 prefix to Network Data.
         #
         br2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', br2.get_state())
 
         # Only 1 NAT64 prefix in Network Data.
diff --git a/tests/scripts/thread-cert/border_router/test_nat64_single_border_router.py b/tests/scripts/thread-cert/border_router/test_nat64_single_border_router.py
index f28158ac3..bcd4a9560 100644
--- a/tests/scripts/thread-cert/border_router/test_nat64_single_border_router.py
+++ b/tests/scripts/thread-cert/border_router/test_nat64_single_border_router.py
@@ -28,6 +28,7 @@
 #
 import unittest
 
+import config
 import thread_cert
 
 # Test description:
@@ -87,7 +88,7 @@ class Nat64SingleBorderRouter(thread_cert.TestCase):
         self.assertEqual('leader', br.get_state())
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router.get_state())
 
         #
diff --git a/tests/scripts/thread-cert/border_router/test_plat_udp_accessiblity.py b/tests/scripts/thread-cert/border_router/test_plat_udp_accessiblity.py
index 2bbcb62c8..f97c1e652 100644
--- a/tests/scripts/thread-cert/border_router/test_plat_udp_accessiblity.py
+++ b/tests/scripts/thread-cert/border_router/test_plat_udp_accessiblity.py
@@ -72,7 +72,7 @@ class TestPlatUdpAccessibility(thread_cert.TestCase):
         br.srp_server_set_enabled(True)
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router.get_state())
 
         # Router1 can ping to/from the Host on infra link.
diff --git a/tests/scripts/thread-cert/border_router/test_radvd_coexist.py b/tests/scripts/thread-cert/border_router/test_radvd_coexist.py
index dde4de5fd..106afefff 100755
--- a/tests/scripts/thread-cert/border_router/test_radvd_coexist.py
+++ b/tests/scripts/thread-cert/border_router/test_radvd_coexist.py
@@ -90,7 +90,7 @@ class SingleBorderRouter(thread_cert.TestCase):
         self.assertEqual('leader', br.get_state())
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router.get_state())
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/border_router/test_single_border_router.py b/tests/scripts/thread-cert/border_router/test_single_border_router.py
index d30dfbb1a..24ba05f43 100755
--- a/tests/scripts/thread-cert/border_router/test_single_border_router.py
+++ b/tests/scripts/thread-cert/border_router/test_single_border_router.py
@@ -88,7 +88,7 @@ class SingleBorderRouter(thread_cert.TestCase):
         self.assertEqual('leader', br.get_state())
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router.get_state())
 
         #
diff --git a/tests/scripts/thread-cert/border_router/test_trel_connectivity.py b/tests/scripts/thread-cert/border_router/test_trel_connectivity.py
index 9d9f31573..ceba885ce 100644
--- a/tests/scripts/thread-cert/border_router/test_trel_connectivity.py
+++ b/tests/scripts/thread-cert/border_router/test_trel_connectivity.py
@@ -28,7 +28,9 @@
 #
 import unittest
 
+import config
 import thread_cert
+
 # Test description:
 #   This test verifies TREL connectivity.
 #
@@ -124,7 +126,7 @@ class TestTrelConnectivity(thread_cert.TestCase):
         self.wait_node_state(router2, 'router', 10)
 
         # Allow the network to stabilize
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         self.collect_ipaddrs()
         self.collect_rloc16s()
diff --git a/tests/scripts/thread-cert/border_router/test_vicarious_router_solicit.py b/tests/scripts/thread-cert/border_router/test_vicarious_router_solicit.py
index 4befa1141..7c09f9601 100755
--- a/tests/scripts/thread-cert/border_router/test_vicarious_router_solicit.py
+++ b/tests/scripts/thread-cert/border_router/test_vicarious_router_solicit.py
@@ -112,7 +112,7 @@ class MultiThreadNetworks(thread_cert.TestCase):
         self.assertEqual('leader', br1.get_state())
 
         router1.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router1.get_state())
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/config.py b/tests/scripts/thread-cert/config.py
index 60266ba87..9ba199ee4 100755
--- a/tests/scripts/thread-cert/config.py
+++ b/tests/scripts/thread-cert/config.py
@@ -125,6 +125,7 @@ RSSI = {
 SNIFFER_ID = int(os.getenv('SNIFFER_ID', 34))
 PANID = 0xface
 
+ROUTER_STARTUP_DELAY = 10
 MAX_NEIGHBOR_AGE = 100
 INFINITE_COST_TIMEOUT = 90
 
diff --git a/tests/scripts/thread-cert/test_anycast.py b/tests/scripts/thread-cert/test_anycast.py
index 70b50dfcb..b05011d1f 100755
--- a/tests/scripts/thread-cert/test_anycast.py
+++ b/tests/scripts/thread-cert/test_anycast.py
@@ -77,7 +77,7 @@ class TestAnycast(thread_cert.TestCase):
 
         for i in range(ROUTER2, ROUTER5 + 1):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
             self.nodes[i].udp_start('::', TEST_UDP_PORT)
 
diff --git a/tests/scripts/thread-cert/test_anycast_locator.py b/tests/scripts/thread-cert/test_anycast_locator.py
index c45da666b..c8165830f 100755
--- a/tests/scripts/thread-cert/test_anycast_locator.py
+++ b/tests/scripts/thread-cert/test_anycast_locator.py
@@ -103,7 +103,7 @@ class AnycastLocator(thread_cert.TestCase):
 
         for node in nodes[1:]:
             node.start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(node.get_state(), 'router')
 
         #
diff --git a/tests/scripts/thread-cert/test_coap_block.py b/tests/scripts/thread-cert/test_coap_block.py
index 0bc1333c4..7c74b0f59 100755
--- a/tests/scripts/thread-cert/test_coap_block.py
+++ b/tests/scripts/thread-cert/test_coap_block.py
@@ -61,7 +61,7 @@ class TestCoapBlockTransfer(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         mleid = self.nodes[LEADER].get_ip6_address(config.ADDRESS_TYPE.ML_EID)
diff --git a/tests/scripts/thread-cert/test_coap_observe.py b/tests/scripts/thread-cert/test_coap_observe.py
index 13bfa8f6c..1071c3c23 100755
--- a/tests/scripts/thread-cert/test_coap_observe.py
+++ b/tests/scripts/thread-cert/test_coap_observe.py
@@ -61,7 +61,7 @@ class TestCoapObserve(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         mleid = self.nodes[LEADER].get_ip6_address(config.ADDRESS_TYPE.ML_EID)
diff --git a/tests/scripts/thread-cert/test_coaps.py b/tests/scripts/thread-cert/test_coaps.py
index 46b43ae76..18a946b10 100755
--- a/tests/scripts/thread-cert/test_coaps.py
+++ b/tests/scripts/thread-cert/test_coaps.py
@@ -56,7 +56,7 @@ class TestCoaps(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         mleid = self.nodes[LEADER].get_ip6_address(config.ADDRESS_TYPE.ML_EID)
diff --git a/tests/scripts/thread-cert/test_dataset_updater.py b/tests/scripts/thread-cert/test_dataset_updater.py
index 0ce709d23..9a1ac3ffe 100755
--- a/tests/scripts/thread-cert/test_dataset_updater.py
+++ b/tests/scripts/thread-cert/test_dataset_updater.py
@@ -70,7 +70,7 @@ class TestDatasetUpdater(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MED].start()
diff --git a/tests/scripts/thread-cert/test_dns_client_config_auto_start.py b/tests/scripts/thread-cert/test_dns_client_config_auto_start.py
index c6b38071a..48cbef362 100755
--- a/tests/scripts/thread-cert/test_dns_client_config_auto_start.py
+++ b/tests/scripts/thread-cert/test_dns_client_config_auto_start.py
@@ -30,6 +30,7 @@
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -76,14 +77,14 @@ class DnsClientConfigAutoStart(thread_cert.TestCase):
         self.assertEqual(leader.get_state(), 'leader')
 
         router.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(router.get_state(), 'router')
 
         # On leader set DNS config explicitly.
 
         leader.dns_set_config(DEFAULT_ADDRESS)
-        config = leader.dns_get_config()
-        self.assertEqual(config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
+        dns_config = leader.dns_get_config()
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
 
         # Start leader to act as SRP server.
 
@@ -101,27 +102,27 @@ class DnsClientConfigAutoStart(thread_cert.TestCase):
         srp_server_address = router.srp_client_get_server_address()
         self.assertEqual(leader.srp_client_get_server_address(), srp_server_address)
 
-        config = router.dns_get_config()
-        self.assertEqual(config['Server'], '[{}]:53'.format(srp_server_address))
+        dns_config = router.dns_get_config()
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(srp_server_address))
 
         # Verify that on leader the default DNS config remains
         # as before (the address explicitly set earlier).
 
-        config = leader.dns_get_config()
-        self.assertEqual(config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
+        dns_config = leader.dns_get_config()
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
 
         # On leader clear DNS config (the explicitly set address)
         # and verify that it adopts the SRP server address.
 
         leader.dns_set_config("::")
-        config = leader.dns_get_config()
-        self.assertEqual(config['Server'], '[{}]:53'.format(srp_server_address))
+        dns_config = leader.dns_get_config()
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(srp_server_address))
 
         # On leader set DNS config explicitly again.
 
         leader.dns_set_config(DEFAULT_ADDRESS)
-        config = leader.dns_get_config()
-        self.assertEqual(config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
+        dns_config = leader.dns_get_config()
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
 
         # Stop SRP server on leader and start it on router.
 
@@ -137,12 +138,12 @@ class DnsClientConfigAutoStart(thread_cert.TestCase):
         # Verify that config on router gets changed while on leader
         # it remains unchanged.
 
-        config = router.dns_get_config()
+        dns_config = router.dns_get_config()
         srp_server_address = router.srp_client_get_server_address()
-        self.assertEqual(config['Server'], '[{}]:53'.format(srp_server_address))
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(srp_server_address))
 
-        config = leader.dns_get_config()
-        self.assertEqual(config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
+        dns_config = leader.dns_get_config()
+        self.assertEqual(dns_config['Server'], '[{}]:53'.format(DEFAULT_ADDRESS))
 
 
 if __name__ == '__main__':
diff --git a/tests/scripts/thread-cert/test_dnssd.py b/tests/scripts/thread-cert/test_dnssd.py
index 4625253df..06d644f9b 100755
--- a/tests/scripts/thread-cert/test_dnssd.py
+++ b/tests/scripts/thread-cert/test_dnssd.py
@@ -30,6 +30,7 @@ import ipaddress
 import typing
 import unittest
 
+import config
 import thread_cert
 
 # Test description:
@@ -90,7 +91,7 @@ class TestDnssd(thread_cert.TestCase):
         client1.start()
         client2.start()
         client3.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client1.get_state(), 'router')
         self.assertEqual(client2.get_state(), 'router')
         self.assertEqual(client3.get_state(), 'router')
diff --git a/tests/scripts/thread-cert/test_dnssd_name_with_special_chars.py b/tests/scripts/thread-cert/test_dnssd_name_with_special_chars.py
index 1d1393e4d..b1f18813e 100644
--- a/tests/scripts/thread-cert/test_dnssd_name_with_special_chars.py
+++ b/tests/scripts/thread-cert/test_dnssd_name_with_special_chars.py
@@ -32,6 +32,7 @@ import unittest
 import logging
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -78,7 +79,7 @@ class TestDnssdNameWithSpecialChars(thread_cert.TestCase):
         self.assertEqual(server.get_state(), 'leader')
 
         client.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
 
         server.srp_server_set_enabled(True)
diff --git a/tests/scripts/thread-cert/test_history_tracker.py b/tests/scripts/thread-cert/test_history_tracker.py
index 6d2efeec9..209c78152 100755
--- a/tests/scripts/thread-cert/test_history_tracker.py
+++ b/tests/scripts/thread-cert/test_history_tracker.py
@@ -30,6 +30,8 @@
 import os
 import unittest
 import sys
+
+import config
 import thread_cert
 
 # Test description:
diff --git a/tests/scripts/thread-cert/test_inform_previous_parent_on_reattach.py b/tests/scripts/thread-cert/test_inform_previous_parent_on_reattach.py
index 6809bc08b..66f87cbb5 100755
--- a/tests/scripts/thread-cert/test_inform_previous_parent_on_reattach.py
+++ b/tests/scripts/thread-cert/test_inform_previous_parent_on_reattach.py
@@ -85,7 +85,7 @@ class TestReset(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(7)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[MED].start()
diff --git a/tests/scripts/thread-cert/test_ipv6_fragmentation.py b/tests/scripts/thread-cert/test_ipv6_fragmentation.py
index 2b5d8e22c..801c16a3f 100755
--- a/tests/scripts/thread-cert/test_ipv6_fragmentation.py
+++ b/tests/scripts/thread-cert/test_ipv6_fragmentation.py
@@ -59,7 +59,7 @@ class TestIPv6Fragmentation(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         mleid_leader = self.nodes[LEADER].get_ip6_address(config.ADDRESS_TYPE.ML_EID)
diff --git a/tests/scripts/thread-cert/test_ipv6_source_selection.py b/tests/scripts/thread-cert/test_ipv6_source_selection.py
index abaa7b127..12a8eabaf 100755
--- a/tests/scripts/thread-cert/test_ipv6_source_selection.py
+++ b/tests/scripts/thread-cert/test_ipv6_source_selection.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import ipv6
 import thread_cert
 
@@ -58,7 +59,7 @@ class TestIPv6SourceSelection(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         leader_aloc = self.nodes[LEADER].get_addr_leader_aloc()
diff --git a/tests/scripts/thread-cert/test_mac_scan.py b/tests/scripts/thread-cert/test_mac_scan.py
index ae493a5e0..7c023c4cf 100755
--- a/tests/scripts/thread-cert/test_mac_scan.py
+++ b/tests/scripts/thread-cert/test_mac_scan.py
@@ -29,6 +29,7 @@
 import logging
 import unittest
 
+import config
 import thread_cert
 
 LEADER = 1
@@ -62,7 +63,7 @@ class Test_MacScan(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         results = self.nodes[LEADER].scan(result=True)
diff --git a/tests/scripts/thread-cert/test_netdata_publisher.py b/tests/scripts/thread-cert/test_netdata_publisher.py
index df14a365e..3cd2f0c13 100755
--- a/tests/scripts/thread-cert/test_netdata_publisher.py
+++ b/tests/scripts/thread-cert/test_netdata_publisher.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -211,7 +212,7 @@ class NetDataPublisher(thread_cert.TestCase):
 
         for router in routers:
             router.start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(router.get_state(), 'router')
 
         for end_dev in end_devs:
diff --git a/tests/scripts/thread-cert/test_on_mesh_prefix.py b/tests/scripts/thread-cert/test_on_mesh_prefix.py
index 16a359711..d69929813 100755
--- a/tests/scripts/thread-cert/test_on_mesh_prefix.py
+++ b/tests/scripts/thread-cert/test_on_mesh_prefix.py
@@ -69,7 +69,7 @@ class Test_OnMeshPrefix(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED1].start()
diff --git a/tests/scripts/thread-cert/test_pbbr_aloc.py b/tests/scripts/thread-cert/test_pbbr_aloc.py
index 312681a55..84ce43bb6 100755
--- a/tests/scripts/thread-cert/test_pbbr_aloc.py
+++ b/tests/scripts/thread-cert/test_pbbr_aloc.py
@@ -29,6 +29,7 @@
 import re
 import unittest
 
+import config
 import thread_cert
 from config import MESH_LOCAL_PREFIX_REGEX_PATTERN, ROUTING_LOCATOR_REGEX_PATTERN
 from pktverify.packet_verifier import PacketVerifier
@@ -80,7 +81,7 @@ class TestPing(thread_cert.TestCase):
 
         pbbr.enable_backbone_router()
         pbbr.start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', pbbr.get_state())
         self.assertTrue(pbbr.is_primary_backbone_router)
 
diff --git a/tests/scripts/thread-cert/test_ping.py b/tests/scripts/thread-cert/test_ping.py
index 13ee63549..660bfd5a2 100755
--- a/tests/scripts/thread-cert/test_ping.py
+++ b/tests/scripts/thread-cert/test_ping.py
@@ -80,11 +80,11 @@ class TestPing(thread_cert.TestCase):
         self.assertEqual('leader', router1.get_state())
 
         router2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router2.get_state())
 
         router3.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router3.get_state())
 
         # 1. ROUTER_1 pings ROUTER_2.
diff --git a/tests/scripts/thread-cert/test_ping_lla_src.py b/tests/scripts/thread-cert/test_ping_lla_src.py
index 2c73b1ce3..3cc0be7a5 100644
--- a/tests/scripts/thread-cert/test_ping_lla_src.py
+++ b/tests/scripts/thread-cert/test_ping_lla_src.py
@@ -79,11 +79,11 @@ class TestPing(thread_cert.TestCase):
         self.assertEqual('leader', router1.get_state())
 
         router2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router2.get_state())
 
         router3.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual('router', router3.get_state())
 
         self.simulator.go(10)
diff --git a/tests/scripts/thread-cert/test_reset.py b/tests/scripts/thread-cert/test_reset.py
index 7c6305f8e..29183af1c 100755
--- a/tests/scripts/thread-cert/test_reset.py
+++ b/tests/scripts/thread-cert/test_reset.py
@@ -60,7 +60,7 @@ class TestReset(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(7)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED].start()
@@ -78,7 +78,7 @@ class TestReset(thread_cert.TestCase):
 
         self.nodes[ROUTER].reset()
         self.nodes[ROUTER].start()
-        self.simulator.go(7)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[ED].reset()
diff --git a/tests/scripts/thread-cert/test_route_table.py b/tests/scripts/thread-cert/test_route_table.py
index 733355994..038d9a5db 100755
--- a/tests/scripts/thread-cert/test_route_table.py
+++ b/tests/scripts/thread-cert/test_route_table.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 
 LEADER = 1
@@ -64,11 +65,11 @@ class TestRouteTable(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
 
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
         self.simulator.go(100)
diff --git a/tests/scripts/thread-cert/test_router_reattach.py b/tests/scripts/thread-cert/test_router_reattach.py
index 154a710df..31b7c26db 100755
--- a/tests/scripts/thread-cert/test_router_reattach.py
+++ b/tests/scripts/thread-cert/test_router_reattach.py
@@ -204,7 +204,7 @@ class test_router_reattach(thread_cert.TestCase):
 
         for i in range(2, 33):
             self.nodes[i].start()
-            self.simulator.go(5)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
             self.assertEqual(self.nodes[i].get_state(), 'router')
 
         self.nodes[2].reset()
diff --git a/tests/scripts/thread-cert/test_service.py b/tests/scripts/thread-cert/test_service.py
index 4be617eb9..c08379b3c 100755
--- a/tests/scripts/thread-cert/test_service.py
+++ b/tests/scripts/thread-cert/test_service.py
@@ -96,7 +96,7 @@ class Test_Service(thread_cert.TestCase):
 
         self.nodes[ROUTER1].start()
         self.nodes[ROUTER2].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER1].get_state(), 'router')
         self.assertEqual(self.nodes[ROUTER2].get_state(), 'router')
 
diff --git a/tests/scripts/thread-cert/test_srp_auto_start_mode.py b/tests/scripts/thread-cert/test_srp_auto_start_mode.py
index 9fc4c09b5..298a74ee6 100755
--- a/tests/scripts/thread-cert/test_srp_auto_start_mode.py
+++ b/tests/scripts/thread-cert/test_srp_auto_start_mode.py
@@ -89,7 +89,7 @@ class SrpAutoStartMode(thread_cert.TestCase):
         server1.start()
         server2.start()
         server3.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(server1.get_state(), 'router')
         self.assertEqual(server2.get_state(), 'router')
         self.assertEqual(server3.get_state(), 'router')
diff --git a/tests/scripts/thread-cert/test_srp_client_change_lease.py b/tests/scripts/thread-cert/test_srp_client_change_lease.py
index 2a360bb27..532194a3d 100755
--- a/tests/scripts/thread-cert/test_srp_client_change_lease.py
+++ b/tests/scripts/thread-cert/test_srp_client_change_lease.py
@@ -29,7 +29,9 @@
 
 import unittest
 
+import config
 import thread_cert
+
 # Test description:
 #   This test verifies the SRP client lease changing works as expected.
 #
@@ -87,7 +89,7 @@ class SrpClientChangeLeaseTime(thread_cert.TestCase):
 
         client.srp_server_set_enabled(False)
         client.start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
 
         #
diff --git a/tests/scripts/thread-cert/test_srp_client_remove_host.py b/tests/scripts/thread-cert/test_srp_client_remove_host.py
index 78f158df5..6de96c183 100755
--- a/tests/scripts/thread-cert/test_srp_client_remove_host.py
+++ b/tests/scripts/thread-cert/test_srp_client_remove_host.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -75,7 +76,7 @@ class SrpRemoveHost(thread_cert.TestCase):
         self.assertEqual(server.get_state(), 'leader')
 
         client.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
 
         server.srp_server_set_enabled(True)
diff --git a/tests/scripts/thread-cert/test_srp_client_save_server_info.py b/tests/scripts/thread-cert/test_srp_client_save_server_info.py
index 2f3bf2f57..df95f4ec1 100755
--- a/tests/scripts/thread-cert/test_srp_client_save_server_info.py
+++ b/tests/scripts/thread-cert/test_srp_client_save_server_info.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
diff --git a/tests/scripts/thread-cert/test_srp_lease.py b/tests/scripts/thread-cert/test_srp_lease.py
index b2252e662..a1a4abe7b 100755
--- a/tests/scripts/thread-cert/test_srp_lease.py
+++ b/tests/scripts/thread-cert/test_srp_lease.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -84,7 +85,7 @@ class SrpRegisterSingleService(thread_cert.TestCase):
 
         client.srp_server_set_enabled(False)
         client.start()
-        self.simulator.go(10)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
 
         #
diff --git a/tests/scripts/thread-cert/test_srp_name_conflicts.py b/tests/scripts/thread-cert/test_srp_name_conflicts.py
index b7fc1241b..daf37b27f 100755
--- a/tests/scripts/thread-cert/test_srp_name_conflicts.py
+++ b/tests/scripts/thread-cert/test_srp_name_conflicts.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -88,12 +89,12 @@ class SrpNameConflicts(thread_cert.TestCase):
 
         client_1.srp_server_set_enabled(False)
         client_1.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client_1.get_state(), 'router')
 
         client_2.srp_server_set_enabled(False)
         client_2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client_2.get_state(), 'router')
 
         #
diff --git a/tests/scripts/thread-cert/test_srp_register_500_services.py b/tests/scripts/thread-cert/test_srp_register_500_services.py
index 8e41196d4..8b639c999 100644
--- a/tests/scripts/thread-cert/test_srp_register_500_services.py
+++ b/tests/scripts/thread-cert/test_srp_register_500_services.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 
 # Test description:
@@ -118,7 +119,7 @@ class SrpRegister500Services(thread_cert.TestCase):
         for router in routers():
             router.srp_server_set_enabled(False)
             router.start()
-            self.simulator.go(3)
+            self.simulator.go(config.ROUTER_STARTUP_DELAY)
 
         for router in routers():
             self.assertEqual(router.get_state(), 'router')
diff --git a/tests/scripts/thread-cert/test_srp_register_single_service.py b/tests/scripts/thread-cert/test_srp_register_single_service.py
index 55f757e52..32f57b513 100755
--- a/tests/scripts/thread-cert/test_srp_register_single_service.py
+++ b/tests/scripts/thread-cert/test_srp_register_single_service.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -81,7 +82,7 @@ class SrpRegisterSingleService(thread_cert.TestCase):
 
         client.srp_server_set_enabled(False)
         client.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
 
         #
diff --git a/tests/scripts/thread-cert/test_srp_server_anycast_mode.py b/tests/scripts/thread-cert/test_srp_server_anycast_mode.py
index 0a9031da8..7313004b3 100755
--- a/tests/scripts/thread-cert/test_srp_server_anycast_mode.py
+++ b/tests/scripts/thread-cert/test_srp_server_anycast_mode.py
@@ -99,7 +99,7 @@ class TestSrpServerAnycastMode(thread_cert.TestCase):
 
         client.start()
         browser.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
         self.assertEqual(browser.get_state(), 'router')
 
diff --git a/tests/scripts/thread-cert/test_srp_server_reboot_port.py b/tests/scripts/thread-cert/test_srp_server_reboot_port.py
index 9a63a2137..41dc355e7 100755
--- a/tests/scripts/thread-cert/test_srp_server_reboot_port.py
+++ b/tests/scripts/thread-cert/test_srp_server_reboot_port.py
@@ -32,6 +32,7 @@ import logging
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -79,7 +80,7 @@ class SrpServerRebootPort(thread_cert.TestCase):
 
         server.srp_server_set_enabled(True)
         server.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(server.get_state(), 'router')
 
         #
diff --git a/tests/scripts/thread-cert/test_srp_sub_type.py b/tests/scripts/thread-cert/test_srp_sub_type.py
index 817ff40c8..0561876d2 100755
--- a/tests/scripts/thread-cert/test_srp_sub_type.py
+++ b/tests/scripts/thread-cert/test_srp_sub_type.py
@@ -31,6 +31,7 @@ import ipaddress
 import unittest
 
 import command
+import config
 import thread_cert
 
 # Test description:
@@ -74,7 +75,7 @@ class SrpSubType(thread_cert.TestCase):
         self.assertEqual(server.get_state(), 'leader')
 
         client.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(client.get_state(), 'router')
 
         server.srp_server_set_enabled(True)
diff --git a/tests/scripts/thread-cert/test_zero_len_external_route.py b/tests/scripts/thread-cert/test_zero_len_external_route.py
index b5f0af99e..a69665bea 100755
--- a/tests/scripts/thread-cert/test_zero_len_external_route.py
+++ b/tests/scripts/thread-cert/test_zero_len_external_route.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 
 # Test description:
@@ -80,7 +81,7 @@ class ZeroLengthExternalRoute(thread_cert.TestCase):
 
         router1.start()
         router2.start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(router1.get_state(), 'router')
         self.assertEqual(router2.get_state(), 'router')
 
diff --git a/tests/scripts/thread-cert/v1_2_LowPower_5_3_01_SSEDAttachment.py b/tests/scripts/thread-cert/v1_2_LowPower_5_3_01_SSEDAttachment.py
index 16ff1420c..7a6c89388 100755
--- a/tests/scripts/thread-cert/v1_2_LowPower_5_3_01_SSEDAttachment.py
+++ b/tests/scripts/thread-cert/v1_2_LowPower_5_3_01_SSEDAttachment.py
@@ -34,6 +34,7 @@ from mac802154 import MacHeader
 from pktverify import consts
 from pktverify.packet_verifier import PacketVerifier
 
+import config
 import thread_cert
 
 LEADER = 1
@@ -71,7 +72,7 @@ class LowPower_5_3_01_SSEDAttachment(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER].get_state(), 'router')
 
         self.nodes[SSED_1].set_csl_period(consts.CSL_DEFAULT_PERIOD)
diff --git a/tests/scripts/thread-cert/v1_2_LowPower_6_1_07_PreferringARouterOverAReed.py b/tests/scripts/thread-cert/v1_2_LowPower_6_1_07_PreferringARouterOverAReed.py
index af84374ac..ca468e425 100755
--- a/tests/scripts/thread-cert/v1_2_LowPower_6_1_07_PreferringARouterOverAReed.py
+++ b/tests/scripts/thread-cert/v1_2_LowPower_6_1_07_PreferringARouterOverAReed.py
@@ -34,6 +34,7 @@ from mle import TlvType
 from pktverify import consts
 from pktverify.packet_verifier import PacketVerifier
 
+import config
 import thread_cert
 
 LEADER = 1
@@ -78,7 +79,7 @@ class LowPower_6_1_07_PreferringARouterOverAReed_Base(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER_1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER_1].get_state(), 'router')
 
         self.nodes[REED_1].start()
diff --git a/tests/scripts/thread-cert/v1_2_LowPower_7_1_01_SingleProbeLinkMetricsWithEnhancedAcks.py b/tests/scripts/thread-cert/v1_2_LowPower_7_1_01_SingleProbeLinkMetricsWithEnhancedAcks.py
index 2b18214b8..5d7f88cb8 100755
--- a/tests/scripts/thread-cert/v1_2_LowPower_7_1_01_SingleProbeLinkMetricsWithEnhancedAcks.py
+++ b/tests/scripts/thread-cert/v1_2_LowPower_7_1_01_SingleProbeLinkMetricsWithEnhancedAcks.py
@@ -32,6 +32,7 @@ import unittest
 from config import ADDRESS_TYPE
 from pktverify import consts
 
+import config
 import thread_cert
 
 LEADER = 1
diff --git a/tests/scripts/thread-cert/v1_2_LowPower_7_2_01_ForwardTrackingSeries.py b/tests/scripts/thread-cert/v1_2_LowPower_7_2_01_ForwardTrackingSeries.py
index 477a030eb..daee92ed6 100755
--- a/tests/scripts/thread-cert/v1_2_LowPower_7_2_01_ForwardTrackingSeries.py
+++ b/tests/scripts/thread-cert/v1_2_LowPower_7_2_01_ForwardTrackingSeries.py
@@ -35,6 +35,7 @@ from pktverify import consts
 from pktverify.null_field import nullField
 from pktverify.packet_verifier import PacketVerifier
 
+import config
 import thread_cert
 
 LEADER = 1
diff --git a/tests/scripts/thread-cert/v1_2_LowPower_test_forward_tracking_series.py b/tests/scripts/thread-cert/v1_2_LowPower_test_forward_tracking_series.py
index ffa7e3fcd..e51f1adf6 100755
--- a/tests/scripts/thread-cert/v1_2_LowPower_test_forward_tracking_series.py
+++ b/tests/scripts/thread-cert/v1_2_LowPower_test_forward_tracking_series.py
@@ -35,6 +35,7 @@ from pktverify import consts
 from pktverify.null_field import nullField
 from pktverify.packet_verifier import PacketVerifier
 
+import config
 import thread_cert
 
 LEADER = 1
diff --git a/tests/scripts/thread-cert/v1_2_router_5_1_1.py b/tests/scripts/thread-cert/v1_2_router_5_1_1.py
index 1520b391d..39e0c357e 100755
--- a/tests/scripts/thread-cert/v1_2_router_5_1_1.py
+++ b/tests/scripts/thread-cert/v1_2_router_5_1_1.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import thread_cert
 import mle
 import network_layer
@@ -56,7 +57,7 @@ class Router_5_1_01(thread_cert.TestCase):
         self.assertEqual(self.nodes[LEADER].get_state(), 'leader')
 
         self.nodes[ROUTER_1].start()
-        self.simulator.go(7)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER_1].get_state(), 'router')
 
         leader_messages = self.simulator.get_messages_sent_by(LEADER)
diff --git a/tests/scripts/thread-cert/v1_2_test_csl_transmission.py b/tests/scripts/thread-cert/v1_2_test_csl_transmission.py
index c7e1ad10b..4022852dc 100755
--- a/tests/scripts/thread-cert/v1_2_test_csl_transmission.py
+++ b/tests/scripts/thread-cert/v1_2_test_csl_transmission.py
@@ -29,6 +29,7 @@
 
 import unittest
 
+import config
 import mle
 import thread_cert
 from pktverify import consts
diff --git a/tests/scripts/thread-cert/v1_2_test_enhanced_frame_pending.py b/tests/scripts/thread-cert/v1_2_test_enhanced_frame_pending.py
index 92eb180e1..a3093ee58 100755
--- a/tests/scripts/thread-cert/v1_2_test_enhanced_frame_pending.py
+++ b/tests/scripts/thread-cert/v1_2_test_enhanced_frame_pending.py
@@ -46,6 +46,7 @@ import unittest
 import pexpect
 
 import thread_cert
+import config
 import common
 
 LEADER = 1
diff --git a/tests/scripts/thread-cert/v1_2_test_enhanced_keep_alive.py b/tests/scripts/thread-cert/v1_2_test_enhanced_keep_alive.py
index 80270d275..04d55d252 100755
--- a/tests/scripts/thread-cert/v1_2_test_enhanced_keep_alive.py
+++ b/tests/scripts/thread-cert/v1_2_test_enhanced_keep_alive.py
@@ -30,6 +30,7 @@
 import unittest
 
 import thread_cert
+import config
 import mle
 
 LEADER = 1
diff --git a/tests/scripts/thread-cert/v1_2_test_parent_selection.py b/tests/scripts/thread-cert/v1_2_test_parent_selection.py
index 154d400fb..432f984ba 100755
--- a/tests/scripts/thread-cert/v1_2_test_parent_selection.py
+++ b/tests/scripts/thread-cert/v1_2_test_parent_selection.py
@@ -30,6 +30,7 @@
 import unittest
 
 import thread_cert
+import config
 import mle
 
 LEADER_1_2 = 1
@@ -111,7 +112,7 @@ class TestParentSelection(thread_cert.TestCase):
 
         self.nodes[ROUTER_1_1].set_router_selection_jitter(1)
         self.nodes[ROUTER_1_1].start()
-        self.simulator.go(5)
+        self.simulator.go(config.ROUTER_STARTUP_DELAY)
         self.assertEqual(self.nodes[ROUTER_1_1].get_state(), 'router')
 
         # Mesh Impacting Criteria - Highest Two-way link quality