diff --git a/src/service/service/service_handlers/l3nm_openconfig/ConfigRules.py b/src/service/service/service_handlers/l3nm_openconfig/ConfigRules.py
index 716d0413abc0ed4897c5825f7471946ea7d28aa3..7527932877f47a092a35f286defb3744e05db109 100644
--- a/src/service/service/service_handlers/l3nm_openconfig/ConfigRules.py
+++ b/src/service/service/service_handlers/l3nm_openconfig/ConfigRules.py
@@ -12,10 +12,17 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Dict, List, Tuple
+from typing import Any, Dict, List, Optional, Tuple
 from common.tools.object_factory.ConfigRule import json_config_rule_delete, json_config_rule_set
 from service.service.service_handler_api.AnyTreeTools import TreeNode
 
+def get_value(field_name : str, *containers, default=None) -> Optional[Any]:
+    if len(containers) == 0: raise Exception('No containers specified')
+    for container in containers:
+        if field_name not in container: continue
+        return container[field_name]
+    return default
+
 def setup_config_rules(
     service_uuid : str, connection_uuid : str, device_uuid : str, endpoint_uuid : str, endpoint_name : str,
     service_settings : TreeNode, device_settings : TreeNode, endpoint_settings : TreeNode, endpoint_acls : List [Tuple]
@@ -29,9 +36,11 @@ def setup_config_rules(
     json_device_settings   : Dict = device_settings.value
     json_endpoint_settings : Dict = endpoint_settings.value
 
-    mtu                       = json_settings.get('mtu',                          1450     )  # 1512
+    settings = (json_settings, json_endpoint_settings, json_device_settings)
+
+    mtu                       = get_value('mtu', *settings, default=1450)   # 1512
     #address_families         = json_settings.get('address_families',             []       )  # ['IPV4']
-    bgp_as                    = json_settings.get('bgp_as',                       65000    )  # 65000
+    bgp_as                    = get_value('bgp_as', *settings, default=65000)   # 65000
 
     router_id                 = json_endpoint_settings.get('router_id',           '0.0.0.0')  # '10.95.0.10'
     route_distinguisher       = json_settings.get('route_distinguisher',          '65000:101'    )  # '60001:801'
@@ -199,21 +208,23 @@ def teardown_config_rules(
 ) -> List[Dict]:
 
     if service_settings  is None: return []
-    if device_settings is None: return []
+    if device_settings   is None: return []
     if endpoint_settings is None: return []
 
     json_settings          : Dict = service_settings.value
     json_device_settings   : Dict = device_settings.value
     json_endpoint_settings : Dict = endpoint_settings.value
 
+    settings = (json_settings, json_endpoint_settings, json_device_settings)
+
     service_short_uuid        = service_uuid.split('-')[-1]
     network_instance_name     = '{:s}-NetInst'.format(service_short_uuid)
     #network_interface_desc    = '{:s}-NetIf'.format(service_uuid)
     #network_subinterface_desc = '{:s}-NetSubIf'.format(service_uuid)
 
-    #mtu                 = json_settings.get('mtu',                          1450     )  # 1512
+    #mtu                       = get_value('mtu', *settings, default=1450)   # 1512
     #address_families    = json_settings.get('address_families',             []       )  # ['IPV4']
-    #bgp_as              = json_settings.get('bgp_as',                       65000    )  # 65000
+    #bgp_as                    = get_value('bgp_as', *settings, default=65000)   # 65000
     route_distinguisher = json_settings.get('route_distinguisher',          '0:0'    )  # '60001:801'
     #sub_interface_index = json_endpoint_settings.get('sub_interface_index', 0        )  # 1
     #router_id           = json_endpoint_settings.get('router_id',           '0.0.0.0')  # '10.95.0.10'
diff --git a/src/service/service/service_handlers/l3nm_openconfig/ConfigRules_test_ocnos.py b/src/service/service/service_handlers/l3nm_openconfig/ConfigRules_test_ocnos.py
index 1f2593b0d494ab42c9af250c18642a380b68bbcd..5fa1d0b5b6931902b4ac50847c90bf67738032ba 100644
--- a/src/service/service/service_handlers/l3nm_openconfig/ConfigRules_test_ocnos.py
+++ b/src/service/service/service_handlers/l3nm_openconfig/ConfigRules_test_ocnos.py
@@ -22,12 +22,12 @@ def setup_config_rules(
 ) -> List[Dict]:
 
     if service_settings  is None: return []
+    if device_settings   is None: return []
     if endpoint_settings is None: return []
-    if device_settings is None: return []
 
     json_settings          : Dict = service_settings.value
-    json_endpoint_settings : Dict = endpoint_settings.value
     json_device_settings   : Dict = device_settings.value
+    json_endpoint_settings : Dict = endpoint_settings.value
 
     mtu                       = json_settings.get('mtu',                          1450     )  # 1512
     #address_families         = json_settings.get('address_families',             []       )  # ['IPV4']
@@ -233,12 +233,12 @@ def teardown_config_rules(
 ) -> List[Dict]:
 
     if service_settings  is None: return []
+    if device_settings   is None: return []
     if endpoint_settings is None: return []
-    if device_settings is None: return []
 
     json_settings          : Dict = service_settings.value
-    json_endpoint_settings : Dict = endpoint_settings.value
     json_device_settings   : Dict = device_settings.value
+    json_endpoint_settings : Dict = endpoint_settings.value
 
     service_short_uuid        = service_uuid.split('-')[-1]
     # network_instance_name     = '{:s}-NetInst'.format(service_short_uuid)