diff --git a/xos/synchronizer/event_steps/test_onu_events.py b/xos/synchronizer/event_steps/test_onu_events.py
new file mode 100644
index 0000000..e1ec0d4
--- /dev/null
+++ b/xos/synchronizer/event_steps/test_onu_events.py
@@ -0,0 +1,134 @@
+# Copyright 2017-present Open Networking Foundation
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+from mock import patch, call, Mock, PropertyMock
+import json
+
+import os, sys
+
+# Hack to load synchronizer framework
+test_path=os.path.abspath(os.path.dirname(os.path.realpath(__file__)))
+xos_dir=os.path.join(test_path, "../../..")
+if not os.path.exists(os.path.join(test_path, "new_base")):
+    xos_dir=os.path.join(test_path, "../../../../../../orchestration/xos/xos")
+    services_dir = os.path.join(xos_dir, "../../xos_services")
+sys.path.append(xos_dir)
+sys.path.append(os.path.join(xos_dir, 'synchronizers', 'new_base'))
+# END Hack to load synchronizer framework
+
+# generate model from xproto
+def get_models_fn(service_name, xproto_name):
+    name = os.path.join(service_name, "xos", xproto_name)
+    if os.path.exists(os.path.join(services_dir, name)):
+        return name
+    else:
+        name = os.path.join(service_name, "xos", "synchronizer", "models", xproto_name)
+        if os.path.exists(os.path.join(services_dir, name)):
+            return name
+    raise Exception("Unable to find service=%s xproto=%s" % (service_name, xproto_name))
+# END generate model from xproto
+
+class TestSyncOLTDevice(unittest.TestCase):
+
+    def setUp(self):
+        global DeferredException
+
+        self.sys_path_save = sys.path
+        sys.path.append(xos_dir)
+        sys.path.append(os.path.join(xos_dir, 'synchronizers', 'new_base'))
+
+        # Setting up the config module
+        from xosconfig import Config
+        config = os.path.join(test_path, "../model_policies/test_config.yaml")
+        Config.clear()
+        Config.init(config, "synchronizer-config-schema.yaml")
+        # END Setting up the config module
+
+        from synchronizers.new_base.mock_modelaccessor_build import build_mock_modelaccessor
+        # build_mock_modelaccessor(xos_dir, services_dir, [get_models_fn("olt-service", "volt.xproto")])
+
+        # FIXME this is to get jenkins to pass the tests, somehow it is running tests in a different order
+        # and apparently it is not overriding the generated model accessor
+        build_mock_modelaccessor(xos_dir, services_dir, [get_models_fn("olt-service", "volt.xproto"),
+                                                         get_models_fn("vsg", "vsg.xproto"),
+                                                         get_models_fn("../profiles/rcord", "rcord.xproto")])
+        import synchronizers.new_base.modelaccessor
+        from onu_event import ONUEventStep, model_accessor
+
+        # import all class names to globals
+        for (k, v) in model_accessor.all_model_classes.items():
+            globals()[k] = v
+
+        self.log = Mock()
+
+        self.event_step = ONUEventStep(self.log)
+
+        self.event = Mock()
+        self.event.value = json.dumps({
+            'status': 'activate',
+            'serial_number': 'BRCM1234',
+            'uni_port_of_id': 'of:00100101',
+            'of_dpid': 'of:109299321'
+        })
+
+        self.onu = Mock()
+        self.onu.serial_number = "BRCM1234"
+        self.onu.pon_port.olt_device.volt_service.id = 1
+
+        self.service = Mock(id=1)
+        self.service.provider_services = []
+
+        self.oss = Mock()
+        self.oss.kind = "OSS"
+        self.oss.leaf_model = Mock()
+
+    def tearDown(self):
+        self.service.provider_services = []
+
+    def test_missing_onu(self):
+        with patch.object(ONUDevice.objects, "get_items") as onu_device_mock:
+            onu_device_mock.side_effect = IndexError("No ONU")
+
+        with self.assertRaises(Exception) as e:
+            self.event_step.process_event(self.event)
+
+        self.assertEqual(e.exception.message, "No ONUDevice with serial_number %s is present in XOS" % self.onu.serial_number)
+
+    def test_do_nothing(self):
+        with patch.object(ONUDevice.objects, "get_items") as onu_device_mock , \
+            patch.object(Service.objects, "get_items") as service_mock, \
+            patch.object(self.log, "info") as logInfo:
+
+            onu_device_mock.return_value = [self.onu]
+            service_mock.return_value = [self.service]
+
+            self.event_step.process_event(self.event)
+
+            logInfo.assert_called_with("Not processing events as no OSS service is present (is it a provider of vOLT?")
+
+    def test_call_oss(self):
+        self.service.provider_services = [self.oss]
+
+        with patch.object(ONUDevice.objects, "get_items") as onu_device_mock , \
+            patch.object(Service.objects, "get_items") as service_mock, \
+            patch.object(self.oss.leaf_model, "validate_onu") as validate_onu:
+
+            onu_device_mock.return_value = [self.onu]
+
+            service_mock.return_value = [self.service]
+
+            self.event_step.process_event(self.event)
+
+            validate_onu.assert_called_with(json.loads(self.event.value))