diff --git a/Dockerfile.synchronizer b/Dockerfile.synchronizer
index 9de15c9..536e006 100644
--- a/Dockerfile.synchronizer
+++ b/Dockerfile.synchronizer
@@ -16,7 +16,7 @@
 
 # xosproject/att-workflow-driver-synchronizer
 
-FROM xosproject/xos-synchronizer-base:2.1.12
+FROM xosproject/xos-synchronizer-base:2.1.19
 
 COPY xos/synchronizer /opt/xos/synchronizers/att-workflow-driver
 COPY VERSION /opt/xos/synchronizers/att-workflow-driver/
diff --git a/xos/synchronizer/event_steps/auth_event.py b/xos/synchronizer/event_steps/auth_event.py
index 9842406..6786c98 100644
--- a/xos/synchronizer/event_steps/auth_event.py
+++ b/xos/synchronizer/event_steps/auth_event.py
@@ -18,7 +18,8 @@
 import os
 import sys
 from synchronizers.new_base.eventstep import EventStep
-from synchronizers.new_base.modelaccessor import VOLTService, AttWorkflowDriverServiceInstance, model_accessor
+from synchronizers.new_base.modelaccessor import model_accessor
+from helpers import AttHelpers
 
 class SubscriberAuthEventStep(EventStep):
     topics = ["authentication.events"]
@@ -27,31 +28,14 @@
     def __init__(self, *args, **kwargs):
         super(SubscriberAuthEventStep, self).__init__(*args, **kwargs)
 
-    def get_onu_sn(self, event):
-        olt_service = VOLTService.objects.first()
-        onu_sn = olt_service.get_onu_sn_from_openflow(event["deviceId"], event["portNumber"])
-        if not onu_sn or onu_sn is None:
-            self.log.exception("authentication.events: Cannot find onu serial number for this event", kafka_event=event)
-            raise Exception("authentication.events: Cannot find onu serial number for this event")
-
-        return onu_sn
-
-    def get_si_by_sn(self, serial_number):
-        try:
-            return AttWorkflowDriverServiceInstance.objects.get(serial_number=serial_number)
-        except IndexError:
-            self.log.exception("authentication.events: Cannot find hippie-oss service instance for this event", kafka_event=value)
-            raise Exception("authentication.events: Cannot find hippie-oss service instance for this event")
-
     def process_event(self, event):
         value = json.loads(event.value)
 
-        onu_sn = self.get_onu_sn(value)
-        si = self.get_si_by_sn(onu_sn)
+        onu_sn = AttHelpers.get_onu_sn(value)
+        si = AttHelpers.get_si_by_sn(onu_sn)
         if not si:
-            self.log.exception("authentication.events: Cannot find hippie-oss service instance for this event", kafka_event=value)
-            raise Exception("authentication.events: Cannot find hippie-oss service instance for this event")
+            self.log.exception("authentication.events: Cannot find att-workflow-driver service instance for this event", kafka_event=value)
+            raise Exception("authentication.events: Cannot find att-workflow-driver service instance for this event")
 
         si.authentication_state = value["authenticationState"];
-        si.no_sync = True
-        si.save(update_fields=["authentication_state", "no_sync", "updated"], always_update_timestamp=True)
+        si.save(update_fields=["authentication_state", "updated"], always_update_timestamp=True)
diff --git a/xos/synchronizer/event_steps/dhcp_event.py b/xos/synchronizer/event_steps/dhcp_event.py
index b41f803..3d04e96 100644
--- a/xos/synchronizer/event_steps/dhcp_event.py
+++ b/xos/synchronizer/event_steps/dhcp_event.py
@@ -19,6 +19,7 @@
 import sys
 from synchronizers.new_base.eventstep import EventStep
 from synchronizers.new_base.modelaccessor import VOLTService, RCORDSubscriber, model_accessor
+from helpers import AttHelpers
 
 class SubscriberDhcpEventStep(EventStep):
     topics = ["dhcp.events"]
@@ -27,30 +28,31 @@
     def __init__(self, *args, **kwargs):
         super(SubscriberDhcpEventStep, self).__init__(*args, **kwargs)
 
-    def get_onu_sn(self, event):
-        olt_service = VOLTService.objects.first()
-        onu_sn = olt_service.get_onu_sn_from_openflow(event["deviceId"], event["portNumber"])
-        if not onu_sn or onu_sn is None:
-            self.log.exception("dhcp.events: Cannot find onu serial number for this event", kafka_event=event)
-            raise Exception("dhcp.events: Cannot find onu serial number for this event")
-
-        return onu_sn
-
     def process_event(self, event):
         value = json.loads(event.value)
 
-        onu_sn = self.get_onu_sn(value)
+        onu_sn = AttHelpers.get_onu_sn(value)
+        si = AttHelpers.get_si_by_sn(onu_sn)
 
-        subscriber = RCORDSubscriber.objects.get(onu_device=onu_sn)
+        if not si:
+            self.log.exception("dhcp.events: Cannot find att-workflow-driver service instance for this event", kafka_event=value)
+            raise Exception("dhcp.events: Cannot find att-workflow-driver service instance for this event")
 
-        self.log.info("dhcp.events: Got event for subscriber", subscriber=subscriber, event_value=value, onu_sn=onu_sn)
+        self.log.info("dhcp.events: Got event for subscriber", event_value=value, onu_sn=onu_sn, si=si)
 
-        # NOTE it will be better to update the SI and use the model policy to update the subscriber,
-        # if this fails for any reason the event is lost
-        if subscriber.ip_address != value["ipAddress"] or \
-            subscriber.mac_address != value["macAddress"]:
-
-            # FIXME apparently it's always saving
-            subscriber.ip_address = value["ipAddress"]
-            subscriber.mac_address = value["macAddress"]
-            subscriber.save()
+        si.dhcp_state = value["messageType"];
+        si.ip_address = value["ipAddress"];
+        si.mac_address = value["macAddress"];
+        si.save(update_fields=["dhcp_state", "ip_address", "mac_address", "updated"], always_update_timestamp=True)
+        # subscriber = RCORDSubscriber.objects.get(onu_device=onu_sn)
+        #
+        #
+        # # NOTE it will be better to update the SI and use the model policy to update the subscriber,
+        # # if this fails for any reason the event is lost
+        #
+        # if value["messageType"] == "DHCPACK":
+        #
+        #     # FIXME apparently it's always saving
+        #     subscriber.ip_address = value["ipAddress"]
+        #     subscriber.mac_address = value["macAddress"]
+        #     subscriber.save()
diff --git a/xos/synchronizer/event_steps/test_auth_event.py b/xos/synchronizer/event_steps/test_auth_event.py
index 08887dd..e04f70b 100644
--- a/xos/synchronizer/event_steps/test_auth_event.py
+++ b/xos/synchronizer/event_steps/test_auth_event.py
@@ -107,5 +107,5 @@
 
             self.event_step.process_event(self.event)
 
-            self.hippie_si.save.assert_called_with(always_update_timestamp=True, update_fields=['authentication_state', 'no_sync', 'updated'])
+            self.hippie_si.save.assert_called_with(always_update_timestamp=True, update_fields=['authentication_state', 'updated'])
             self.assertEqual(self.hippie_si.authentication_state, 'APPROVED')
diff --git a/xos/synchronizer/event_steps/test_dhcp_event.py b/xos/synchronizer/event_steps/test_dhcp_event.py
index a13b2b3..a31bf3f 100644
--- a/xos/synchronizer/event_steps/test_dhcp_event.py
+++ b/xos/synchronizer/event_steps/test_dhcp_event.py
@@ -81,13 +81,17 @@
         self.volt.name = "vOLT"
         self.volt.leaf_model = Mock()
 
-        self.subscriber = RCORDSubscriber()
-        self.subscriber.onu_device = "BRCM1234"
-        self.subscriber.save = 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 = AttWorkflowDriverServiceInstance()
+        self.si.serial_number = "BRCM1234"
+        self.si.save = Mock()
+
 
     def tearDown(self):
         sys.path = self.sys_path_save
@@ -98,19 +102,21 @@
             "deviceId" : "of:0000000000000001",
             "portNumber" : "1",
             "macAddress" : self.mac_address,
-            "ipAddress" : self.ip_address
+            "ipAddress" : self.ip_address,
+            "messageType": "DHCPREQUEST"
         })
 
         with patch.object(VOLTService.objects, "get_items") as volt_service_mock, \
-            patch.object(RCORDSubscriber.objects, "get_items") as subscriber_mock, \
+            patch.object(AttWorkflowDriverServiceInstance.objects, "get_items") as si_mock, \
             patch.object(self.volt, "get_onu_sn_from_openflow") as get_onu_sn:
 
             volt_service_mock.return_value = [self.volt]
             get_onu_sn.return_value = "BRCM1234"
-            subscriber_mock.return_value = [self.subscriber]
+            si_mock.return_value = [self.si]
 
             self.event_step.process_event(self.event)
 
-            self.subscriber.save.assert_called()
-            self.assertEqual(self.subscriber.mac_address, self.mac_address)
-            self.assertEqual(self.subscriber.ip_address, self.ip_address)
+            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)
diff --git a/xos/synchronizer/helpers.py b/xos/synchronizer/helpers.py
index 14f0eb4..9fffd7c 100644
--- a/xos/synchronizer/helpers.py
+++ b/xos/synchronizer/helpers.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 from synchronizers.new_base.syncstep import DeferredException
-from synchronizers.new_base.modelaccessor import AttWorkflowDriverWhiteListEntry, ONUDevice, model_accessor
+from synchronizers.new_base.modelaccessor import AttWorkflowDriverWhiteListEntry, AttWorkflowDriverServiceInstance, ONUDevice, VOLTService, model_accessor
 
 from xosconfig import Config
 from multistructlog import create_logger
@@ -52,8 +52,32 @@
             raise DeferredException("ONU device %s is not know to XOS yet" % att_si.serial_number)
 
         if pon_port.port_no != whitelisted.pon_port_id or att_si.of_dpid != whitelisted.device_id:
-            log.warn("ONU disable as location don't match", object=str(att_si), serial_number=att_si.serial_number,
+            log.warn("ONU disable as location don't match",
+                     object=str(att_si),
+                     serial_number=att_si.serial_number,
+                     pon_port=pon_port.port_no,
+                     whitelisted_pon_port=whitelisted.pon_port_id,
+                     device_id=att_si.of_dpid,
+                     whitelisted_device_id=whitelisted.device_id,
                      **att_si.tologdict())
             return [False, "ONU activated in wrong location"]
 
-        return [True, "ONU has been validated"]
\ No newline at end of file
+        return [True, "ONU has been validated"]
+
+    @staticmethod
+    def get_onu_sn(event):
+        olt_service = VOLTService.objects.first()
+        onu_sn = olt_service.get_onu_sn_from_openflow(event["deviceId"], event["portNumber"])
+        if not onu_sn or onu_sn is None:
+            log.exception("Cannot find onu serial number for this event", kafka_event=event)
+            raise Exception("Cannot find onu serial number for this event")
+
+        return onu_sn
+
+    @staticmethod
+    def get_si_by_sn(serial_number):
+        try:
+            return AttWorkflowDriverServiceInstance.objects.get(serial_number=serial_number)
+        except IndexError:
+            log.exception("Cannot find att-workflow-driver service instance for this serial number", serial_number=serial_number)
+            raise Exception("Cannot find att-workflow-driver service instance for this serial number %s", serial_number)
\ No newline at end of file
diff --git a/xos/synchronizer/model_policies/model_policy_att_workflow_driver_serviceinstance.py b/xos/synchronizer/model_policies/model_policy_att_workflow_driver_serviceinstance.py
index 8513d41..32d0eaa 100644
--- a/xos/synchronizer/model_policies/model_policy_att_workflow_driver_serviceinstance.py
+++ b/xos/synchronizer/model_policies/model_policy_att_workflow_driver_serviceinstance.py
@@ -46,7 +46,7 @@
             self.validate_onu_state(si)
         else:
             # just clean the status
-            si.status_message = ""
+            si.status_message = "ONU has been disabled"
 
         # handling the subscriber status
         subscriber = self.get_subscriber(si.serial_number)
@@ -101,12 +101,18 @@
             subscriber.status = "auth-failed"
             si.status_message += " - Authentication denied"
 
-        if cur_status == subscriber.status:
+        # NOTE we save the subscriber only if:
+        # - the status has changed
+        # - we get a DHCPACK event
+        if cur_status != subscriber.status or si.dhcp_state == "DHCPACK":
+            self.logger.debug("MODEL_POLICY: updating subscriber", onu_device=subscriber.onu_device, authentication_state=si.authentication_state, subscriber_status=subscriber.status)
+            if si.ip_address and si.mac_address:
+                subscriber.ip_address = si.ip_address
+                subscriber.mac_address = si.mac_address
+            subscriber.save(always_update_timestamp=True)
+        else:
             self.logger.debug("MODEL_POLICY: subscriber status has not changed", onu_device=subscriber.onu_device,
                               authentication_state=si.authentication_state, subscriber_status=subscriber.status)
-        else:
-            self.logger.debug("MODEL_POLICY: updating subscriber", onu_device=subscriber.onu_device, authentication_state=si.authentication_state, subscriber_status=subscriber.status)
-            subscriber.save(always_update_timestamp=True)
 
     def handle_delete(self, si):
         pass
diff --git a/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py b/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
index 8e15202..afa4183 100644
--- a/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
+++ b/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
@@ -240,6 +240,22 @@
             self.policy.update_subscriber(sub, self.si)
             sub_save.assert_not_called()
 
+    def test_update_subscriber_dhcp(self):
+        sub = RCORDSubscriber(
+            onu_device="BRCM1234"
+        )
+
+        self.si.dhcp_state = "DHCPACK"
+        self.si.ip_address = "1234"
+        self.si.mac_address = "4321"
+
+        with patch.object(sub, "save") as sub_save:
+            self.policy.update_subscriber(sub, self.si)
+            sub_save.assert_called()
+            self.assertEqual(sub.mac_address, self.si.mac_address)
+            self.assertEqual(sub.ip_address, self.si.ip_address)
+
+
 
     def test_handle_update_subscriber(self):
         self.si.onu_state = "DISABLED"
@@ -249,7 +265,6 @@
         )
 
         with patch.object(self.policy, "get_subscriber") as get_subscriber, \
-            patch.object(self.policy, "update_onu") as update_onu, \
             patch.object(self.policy, "update_subscriber") as update_subscriber:
 
             get_subscriber.return_value = None
diff --git a/xos/synchronizer/models/att-workflow-driver.xproto b/xos/synchronizer/models/att-workflow-driver.xproto
index 7216dff..233eb00 100644
--- a/xos/synchronizer/models/att-workflow-driver.xproto
+++ b/xos/synchronizer/models/att-workflow-driver.xproto
@@ -16,6 +16,9 @@
     required int32 uni_port_id = 5 [db_index = False];
     required string onu_state = 6 [max_length = 254, db_index = False, default = "AWAITING", choices = "(('AWAITING', 'Awaiting'), ('ENABLED', 'Enabled'), ('DISABLED', 'Disabled'))"];
     optional string status_message = 7 [max_length = 254, db_index = False, default = ""];
+    optional string dhcp_state = 8 [max_length = 254, db_index = False, default = "AWAITING", choices = "(('AWAITING', 'Awaiting'), ('DHCPDISCOVER', 'DHCPDISCOVER'), ('DHCPACK', 'DHCPACK'), ('DHCPREQUEST', 'DHCPREQUEST'))"];
+    optional string ip_address = 9 [max_length = 20, db_index = False];
+    optional string mac_address = 10 [max_length = 20, db_index = False];
 }
 
 message AttWorkflowDriverWhiteListEntry (XOSBase) {