diff --git a/xos/synchronizer/event_steps/dhcp_event.py b/xos/synchronizer/event_steps/dhcp_event.py
new file mode 100644
index 0000000..42f0858
--- /dev/null
+++ b/xos/synchronizer/event_steps/dhcp_event.py
@@ -0,0 +1,46 @@
+
+# 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 json
+import time
+import os
+import sys
+from xossynchronizer.event_steps.eventstep import EventStep
+from helpers import TtHelpers
+
+class SubscriberDhcpEventStep(EventStep):
+    topics = ["dhcp.events"]
+    technology = "kafka"
+
+    def __init__(self, *args, **kwargs):
+        super(SubscriberDhcpEventStep, self).__init__(*args, **kwargs)
+
+    def process_event(self, event):
+        value = json.loads(event.value)
+
+        onu_sn = TtHelpers.get_onu_sn(self.model_accessor, self.log, value)
+        si = TtHelpers.get_si_by_sn(self.model_accessor, self.log, onu_sn)
+
+        if not si:
+            self.log.exception("dhcp.events: Cannot find tt-workflow-driver service instance for this event", kafka_event=value)
+            raise Exception("dhcp.events: Cannot find tt-workflow-driver service instance for this event")
+
+        self.log.info("dhcp.events: Got event for subscriber", event_value=value, onu_sn=onu_sn, si=si)
+
+        si.dhcp_state = value["messageType"]
+        si.ip_address = value["ipAddress"]
+        si.mac_address = value["macAddress"]
+
+        si.save_changed_fields(always_update_timestamp=True)
diff --git a/xos/synchronizer/event_steps/onu_event.py b/xos/synchronizer/event_steps/onu_event.py
new file mode 100644
index 0000000..386942f
--- /dev/null
+++ b/xos/synchronizer/event_steps/onu_event.py
@@ -0,0 +1,61 @@
+
+# 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 json
+from xossynchronizer.event_steps.eventstep import EventStep
+
+class ONUEventStep(EventStep):
+    topics = ["onu.events"]
+    technology = "kafka"
+
+    max_onu_retry = 50
+
+    def __init__(self, *args, **kwargs):
+        super(ONUEventStep, self).__init__(*args, **kwargs)
+
+    def get_tt_si(self, event):
+        try:
+            tt_si = self.model_accessor.TtWorkflowDriverServiceInstance.objects.get(serial_number=event["serial_number"])
+            tt_si.no_sync = False;
+            tt_si.uni_port_id = event["uni_port_id"]
+            tt_si.of_dpid = event["of_dpid"]
+            self.log.debug("onu.events: Found existing TtWorkflowDriverServiceInstance", si=tt_si)
+        except IndexError:
+            # create an TtWorkflowDriverServiceInstance, the validation will be triggered in the corresponding sync step
+            tt_si = self.model_accessor.TtWorkflowDriverServiceInstance(
+                serial_number=event["serial_number"],
+                of_dpid=event["of_dpid"],
+                uni_port_id=event["uni_port_id"],
+                owner=self.model_accessor.TtWorkflowDriverService.objects.first() # we assume there is only one TtWorkflowDriverService
+            )
+            self.log.debug("onu.events: Created new TtWorkflowDriverServiceInstance", si=tt_si)
+        return tt_si
+
+    def process_event(self, event):
+        value = json.loads(event.value)
+        self.log.info("onu.events: received event", value=value)
+
+        if value["status"] == "activated":
+            self.log.info("onu.events: activated onu", value=value)
+            tt_si = self.get_tt_si(value)
+            tt_si.onu_state = "ENABLED"
+            tt_si.save_changed_fields(always_update_timestamp=True)
+        elif value["status"] == "disabled":
+            self.log.info("onu.events: disabled onu, not taking any action", value=value)
+            return
+        else:
+            self.log.warn("onu.events: Unknown status value: %s" % value["status"], value=value)
+            return
diff --git a/xos/synchronizer/event_steps/test_dhcp_event.py b/xos/synchronizer/event_steps/test_dhcp_event.py
new file mode 100644
index 0000000..d7934da
--- /dev/null
+++ b/xos/synchronizer/event_steps/test_dhcp_event.py
@@ -0,0 +1,110 @@
+# 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
+
+test_path=os.path.abspath(os.path.dirname(os.path.realpath(__file__)))
+
+class TestSubscriberAuthEvent(unittest.TestCase):
+
+    def setUp(self):
+
+        self.sys_path_save = sys.path
+
+        # Setting up the config module
+        from xosconfig import Config
+        config = os.path.join(test_path, "../test_config.yaml")
+        Config.clear()
+        Config.init(config, "synchronizer-config-schema.yaml")
+        from multistructlog import create_logger
+        log = create_logger(Config().get('logging'))
+        # END Setting up the config module
+
+        from xossynchronizer.mock_modelaccessor_build import mock_modelaccessor_config
+        mock_modelaccessor_config(test_path, [("tt-workflow-driver", "tt-workflow-driver.xproto"),
+                                              ("olt-service", "volt.xproto"),
+                                              ("rcord", "rcord.xproto")])
+
+        import xossynchronizer.modelaccessor
+        import mock_modelaccessor
+        reload(mock_modelaccessor) # in case nose2 loaded it in a previous test
+        reload(xossynchronizer.modelaccessor)      # in case nose2 loaded it in a previous test
+
+        from xossynchronizer.modelaccessor import model_accessor
+        from dhcp_event import SubscriberDhcpEventStep
+
+        # import all class names to globals
+        for (k, v) in model_accessor.all_model_classes.items():
+            globals()[k] = v
+
+        self.model_accessor = model_accessor
+        self.log = log
+
+        self.event_step = SubscriberDhcpEventStep(model_accessor=self.model_accessor, log=self.log)
+
+        self.event = Mock()
+
+        self.volt = Mock()
+        self.volt.name = "vOLT"
+        self.volt.leaf_model = Mock()
+
+        # self.subscriber = RCORDSubscriber()
+        # self.subscriber.onu_device = "BRCM1234"
+        # self.subscriber.save = Mock()
+
+        self.mac_address = "00:AA:00:00:00:01"
+        self.ip_address = "192.168.3.5"
+
+        self.si = TtWorkflowDriverServiceInstance()
+        self.si.serial_number = "BRCM1234"
+        self.si.save = Mock()
+
+
+    def tearDown(self):
+        sys.path = self.sys_path_save
+
+    def test_dhcp_subscriber(self):
+
+        self.event.value = json.dumps({
+            "deviceId" : "of:0000000000000001",
+            "portNumber" : "1",
+            "macAddress" : self.mac_address,
+            "ipAddress" : self.ip_address,
+            "messageType": "DHCPREQUEST"
+        })
+
+        with patch.object(VOLTService.objects, "get_items") as volt_service_mock, \
+            patch.object(TtWorkflowDriverServiceInstance.objects, "get_items") as si_mock, \
+            patch.object(self.volt, "get_onu_sn_from_openflow") as get_onu_sn:
+
+            self.assertTrue(VOLTService.objects.first() is not None)
+
+            volt_service_mock.return_value = [self.volt]
+            get_onu_sn.return_value = "BRCM1234"
+            si_mock.return_value = [self.si]
+
+            self.event_step.process_event(self.event)
+
+            self.si.save.assert_called()
+            self.assertEqual(self.si.dhcp_state, "DHCPREQUEST")
+            self.assertEqual(self.si.mac_address, self.mac_address)
+            self.assertEqual(self.si.ip_address, self.ip_address)
+
+if __name__ == '__main__':
+    sys.path.append("..") # for import of helpers.py
+    unittest.main()
\ No newline at end of file
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..ea368d5
--- /dev/null
+++ b/xos/synchronizer/event_steps/test_onu_events.py
@@ -0,0 +1,135 @@
+# 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
+
+test_path=os.path.abspath(os.path.dirname(os.path.realpath(__file__)))
+
+class TestSyncOLTDevice(unittest.TestCase):
+
+    def setUp(self):
+
+        self.sys_path_save = sys.path
+
+        # Setting up the config module
+        from xosconfig import Config
+        config = os.path.join(test_path, "../test_config.yaml")
+        Config.clear()
+        Config.init(config, "synchronizer-config-schema.yaml")
+        # END Setting up the config module
+
+        from xossynchronizer.mock_modelaccessor_build import mock_modelaccessor_config
+        mock_modelaccessor_config(test_path, [("tt-workflow-driver", "tt-workflow-driver.xproto"),
+                                              ("olt-service", "volt.xproto"),
+                                              ("rcord", "rcord.xproto")])
+
+        import xossynchronizer.modelaccessor
+        import mock_modelaccessor
+        reload(mock_modelaccessor) # in case nose2 loaded it in a previous test
+        reload(xossynchronizer.modelaccessor)      # in case nose2 loaded it in a previous test
+
+        from xossynchronizer.modelaccessor import model_accessor
+        from onu_event import ONUEventStep
+
+        # import all class names to globals
+        for (k, v) in model_accessor.all_model_classes.items():
+            globals()[k] = v
+
+        self.model_accessor = model_accessor
+        self.log = Mock()
+
+        self.event_step = ONUEventStep(model_accessor=self.model_accessor, log=self.log)
+
+        self.event = Mock()
+        self.event_dict = {
+            'status': 'activated',
+            'serial_number': 'BRCM1234',
+            'of_dpid': 'of:109299321',
+            'uni_port_id': 16
+        }
+        self.event.value = json.dumps(self.event_dict)
+
+        self.tt = TtWorkflowDriverService(name="tt-workflow-driver")
+
+    def tearDown(self):
+        sys.path = self.sys_path_save
+
+
+    def test_create_instance(self):
+
+        with patch.object(TtWorkflowDriverServiceInstance.objects, "get_items") as tt_si_mock , \
+            patch.object(TtWorkflowDriverService.objects, "get_items") as service_mock, \
+            patch.object(TtWorkflowDriverServiceInstance, "save", autospec=True) as mock_save:
+
+            tt_si_mock.return_value = []
+            service_mock.return_value = [self.tt]
+
+            self.event_step.process_event(self.event)
+
+            tt_si = mock_save.call_args[0][0]
+
+            self.assertEqual(mock_save.call_count, 1)
+
+            self.assertEqual(tt_si.serial_number, self.event_dict['serial_number'])
+            self.assertEqual(tt_si.of_dpid, self.event_dict['of_dpid'])
+            self.assertEqual(tt_si.uni_port_id, self.event_dict['uni_port_id'])
+            self.assertEqual(tt_si.onu_state, "ENABLED")
+
+    def test_reuse_instance(self):
+
+        si = TtWorkflowDriverServiceInstance(
+            serial_number=self.event_dict["serial_number"],
+            of_dpid="foo",
+            uni_port_id="foo"
+        )
+
+        with patch.object(TtWorkflowDriverServiceInstance.objects, "get_items") as tt_si_mock , \
+            patch.object(TtWorkflowDriverServiceInstance, "save", autospec=True) as mock_save:
+
+            tt_si_mock.return_value = [si]
+
+            self.event_step.process_event(self.event)
+
+            tt_si = mock_save.call_args[0][0]
+
+            self.assertEqual(mock_save.call_count, 1)
+
+            self.assertEqual(tt_si.serial_number, self.event_dict['serial_number'])
+            self.assertEqual(tt_si.of_dpid, self.event_dict['of_dpid'])
+            self.assertEqual(tt_si.uni_port_id, self.event_dict['uni_port_id'])
+            self.assertEqual(tt_si.onu_state, "ENABLED")
+
+    def test_disable_onu(self):
+        self.event_dict = {
+            'status': 'disabled',
+            'serial_number': 'BRCM1234',
+            'of_dpid': 'of:109299321',
+            'uni_port_id': 16
+        }
+        self.event.value = json.dumps(self.event_dict)
+
+        with patch.object(TtWorkflowDriverServiceInstance, "save", autospec=True) as mock_save:
+
+            self.event_step.process_event(self.event)
+
+            self.assertEqual(mock_save.call_count, 0)
+            
+
+if __name__ == '__main__':
+    sys.path.append("..")  # for import of helpers.py
+    unittest.main()
\ No newline at end of file