diff --git a/docs/static/vOLTService_ER_diagram.png b/docs/static/vOLTService_ER_diagram.png
index 3193d93..5c832d3 100644
--- a/docs/static/vOLTService_ER_diagram.png
+++ b/docs/static/vOLTService_ER_diagram.png
Binary files differ
diff --git a/xos/synchronizer/models/models.py b/xos/synchronizer/models/models.py
index 3dcefae..3cd13f4 100644
--- a/xos/synchronizer/models/models.py
+++ b/xos/synchronizer/models/models.py
@@ -22,6 +22,8 @@
 from models_decl import PONPort_decl
 from models_decl import NNIPort_decl
 from models_decl import ONUDevice_decl
+from models_decl import PONONUPort_decl
+from models_decl import UNIPort_decl
 
 class VOLTService(VOLTService_decl):
     class Meta:
@@ -125,5 +127,13 @@
 
 class ONUDevice(ONUDevice_decl):
     class Meta:
-        proxy = True 
+        proxy = True
+
+class PONONUPort(PONONUPort_decl):
+    class Meta:
+        proxy = True
+
+class UNIPort(UNIPort_decl):
+    class Meta:
+        proxy = True
 
diff --git a/xos/synchronizer/models/volt.xproto b/xos/synchronizer/models/volt.xproto
index 3106210..2824de3 100644
--- a/xos/synchronizer/models/volt.xproto
+++ b/xos/synchronizer/models/volt.xproto
@@ -52,7 +52,8 @@
 }
 
 message PONPort (PortBase){
-    option verbose_name = "PON Port";
+    option verbose_name = "OLT PON Port";
+    option description="OLT Side PON Port";
 
     required manytoone olt_device->OLTDevice:pon_ports = 1 [db_index = True, null = False, blank = False];
     required int32 s_tag = 2 [help_text = "S Tag", null = False, db_index = False, blank = False];
@@ -78,6 +79,17 @@
     optional string connect_status = 8 [help_text = "connect_status", null = True, db_index = False, blank = False, feedback_state = True];
 }
 
+message PONONUPort (PortBase) {
+    option verbose_name = "ONU PON Port";
+    option description="ONU Side PON Port";
+    required manytoone onu_device->ONUDevice:pononu_ports = 1 [db_index = True, null = False, blank = False];
+}
+
+message UNIPort (PortBase) {
+    option verbose_name = "UNI Port";
+    required manytoone onu_device->ONUDevice:uni_ports = 1 [db_index = True, null = False, blank = False];
+}
+
 message VOLTServiceInstance (ServiceInstance){
     option kind = "vOLT";
     option owner_class_name = "VOLTService";
diff --git a/xos/synchronizer/pull_steps/pull_onus.py b/xos/synchronizer/pull_steps/pull_onus.py
index b762297..13a051b 100644
--- a/xos/synchronizer/pull_steps/pull_onus.py
+++ b/xos/synchronizer/pull_steps/pull_onus.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 
 from synchronizers.new_base.pullstep import PullStep
-from synchronizers.new_base.modelaccessor import model_accessor, ONUDevice, VOLTService, OLTDevice, PONPort
+from synchronizers.new_base.modelaccessor import model_accessor, ONUDevice, VOLTService, OLTDevice, PONPort, PONONUPort, UNIPort
 
 from xosconfig import Config
 from multistructlog import create_logger
@@ -57,7 +57,7 @@
             log.debug("received devices", onus=devices)
 
             # TODO
-            # [ ] delete ONUS as ONUDevice.objects.all() - updated OLTs
+            # [ ] delete ONUS as ONUDevice.objects.all() - updated ONUs
 
             if r.status_code != 200:
                 log.info("It was not possible to fetch devices from VOLTHA")
@@ -83,6 +83,8 @@
 
                 if model.enacted < model.updated:
                     log.info("Skipping pull on ONUDevice %s as enacted < updated" % model.serial_number, serial_number=model.serial_number, id=model.id, enacted=model.enacted, updated=model.updated)
+                    # if we are not updating the device we still need to pull ports
+                    self.fetch_onu_ports(model)
                     return
 
             except IndexError:
@@ -109,12 +111,83 @@
 
             model.save()
 
+            self.fetch_onu_ports(model)
+
             updated_onus.append(model)
 
         return updated_onus
 
+    def fetch_onu_ports(self, onu):
+        voltha_url = Helpers.get_voltha_info(self.volt_service)['url']
+        voltha_port = Helpers.get_voltha_info(self.volt_service)['port']
 
+        try:
+            r = requests.get("%s:%s/api/v1/devices/%s/ports" % (voltha_url, voltha_port, onu.device_id))
 
+            if r.status_code != 200:
+                log.info("It was not possible to fetch ports from VOLTHA for ONUDevice %s" % onu.device_id)
 
+            ports = r.json()['items']
+
+            log.debug("received ports", ports=ports, onu=onu.device_id)
+
+            self.create_or_update_ports(ports, onu)
+
+        except ConnectionError, e:
+            log.warn("It was not possible to connect to VOLTHA", reason=e)
+            return
+        except InvalidURL, e:
+            log.warn("VOLTHA url is invalid, is it configured in the VOLTService?", reason=e)
+            return
+        return
+
+    def create_or_update_ports(self, ports, onu):
+        uni_ports = [p for p in ports if "ETHERNET_UNI" in p["type"]]
+        pon_onu_ports = [p for p in ports if "PON_ONU" in p["type"]]
+
+        self.create_or_update_uni_port(uni_ports, onu)
+        self.create_or_update_pon_onu_port(pon_onu_ports, onu)
+
+    def create_or_update_uni_port(self, uni_ports, onu):
+        update_ports = []
+
+        for port in uni_ports:
+            try:
+                model = UNIPort.objects.filter(port_no=port["port_no"], onu_device_id=onu.id)[0]
+                log.debug("UNIPort already exists, updating it", port_no=port["port_no"], onu_device_id=onu.id)
+            except IndexError:
+                model = UNIPort()
+                model.port_no = port["port_no"]
+                model.onu_device_id = onu.id
+                model.name = port["label"]
+                log.debug("UNIPort is new, creating it", port_no=port["port_no"], onu_device_id=onu.id)
+
+            model.admin_state = port["admin_state"]
+            model.oper_status = port["oper_status"]
+            model.save()
+            update_ports.append(model)
+        return update_ports
+
+    def create_or_update_pon_onu_port(self, pon_onu_ports, onu):
+        update_ports = []
+
+        for port in pon_onu_ports:
+            try:
+                model = PONONUPort.objects.filter(port_no=port["port_no"], onu_device_id=onu.id)[0]
+                model.xos_managed = False
+                log.debug("PONONUPort already exists, updating it", port_no=port["port_no"], onu_device_id=onu.id)
+            except IndexError:
+                model = PONONUPort()
+                model.port_no = port["port_no"]
+                model.onu_device_id = onu.id
+                model.name = port["label"]
+                model.xos_managed = False
+                log.debug("PONONUPort is new, creating it", port_no=port["port_no"], onu_device_id=onu.id)
+
+            model.admin_state = port["admin_state"]
+            model.oper_status = port["oper_status"]
+            model.save()
+            update_ports.append(model)
+        return update_ports
 
 
diff --git a/xos/synchronizer/pull_steps/test_pull_onus.py b/xos/synchronizer/pull_steps/test_pull_onus.py
index a2b948b..c888639 100644
--- a/xos/synchronizer/pull_steps/test_pull_onus.py
+++ b/xos/synchronizer/pull_steps/test_pull_onus.py
@@ -109,6 +109,11 @@
             ]
         }
 
+        # TODO add ports
+        self.ports = {
+            "items": []
+        }
+
     def tearDown(self):
         sys.path = self.sys_path_save
 
@@ -122,70 +127,27 @@
         with patch.object(VOLTService.objects, "all") as olt_service_mock, \
                 patch.object(OLTDevice.objects, "get") as mock_olt_device, \
                 patch.object(PONPort.objects, "get") as mock_pon_port, \
-                patch.object(ONUDevice, "save") as mock_save:
+                patch.object(ONUDevice, "save", autospec=True) as mock_save:
             olt_service_mock.return_value = [self.volt_service]
             mock_pon_port.return_value = self.pon_port
             mock_olt_device.return_value = self.olt
 
             m.get("http://voltha_url:1234/api/v1/devices", status_code=200, json=self.devices)
+            m.get("http://voltha_url:1234/api/v1/devices/0001130158f01b2d/ports", status_code=200, json=self.ports)
 
             self.sync_step().pull_records()
 
-            # TODO how to asster this?
-            # self.assertEqual(existing_olt.admin_state, "ENABLED")
-            # self.assertEqual(existing_olt.oper_status, "ACTIVE")
-            # self.assertEqual(existing_olt.volt_service_id, "volt_service_id")
-            # self.assertEqual(existing_olt.device_id, "test_id")
-            # self.assertEqual(existing_olt.of_id, "of_id")
-            # self.assertEqual(existing_olt.dp_id, "of:0000000ce2314000")
+            saved_onu = mock_save.call_args[0][0]
 
-            mock_save.assert_called_with()
+            self.assertEqual(saved_onu.admin_state, "ENABLED")
+            self.assertEqual(saved_onu.oper_status, "ACTIVE")
+            self.assertEqual(saved_onu.connect_status, "REACHABLE")
+            self.assertEqual(saved_onu.device_type, "broadcom_onu")
+            self.assertEqual(saved_onu.vendor, "Broadcom")
+            self.assertEqual(saved_onu.device_id, "0001130158f01b2d")
 
-    @requests_mock.Mocker()
-    def _test_pull_existing(self, m):
+            self.assertEqual(mock_save.call_count, 1)
 
-        existing_olt = Mock()
-        existing_olt.enacted = 2
-        existing_olt.updated = 1
-
-        with patch.object(VOLTService.objects, "all") as olt_service_mock, \
-        patch.object(OLTDevice.objects, "filter") as mock_get, \
-        patch.object(existing_olt, "save") as  mock_save:
-            olt_service_mock.return_value = [self.volt_service]
-            mock_get.return_value = [existing_olt]
-
-            m.get("http://voltha_url:1234/api/v1/devices", status_code=200, json=self.devices)
-            m.get("http://voltha_url:1234/api/v1/logical_devices", status_code=200, json=self.logical_devices)
-
-            self.sync_step().pull_records()
-
-            self.assertEqual(existing_olt.admin_state, "ENABLED")
-            self.assertEqual(existing_olt.oper_status, "ACTIVE")
-            self.assertEqual(existing_olt.volt_service_id, "volt_service_id")
-            self.assertEqual(existing_olt.device_id, "test_id")
-            self.assertEqual(existing_olt.of_id, "of_id")
-            self.assertEqual(existing_olt.dp_id, "of:0000000ce2314000")
-
-            mock_save.assert_called()
-
-    @requests_mock.Mocker()
-    def _test_pull_existing_do_not_sync(self, m):
-        existing_olt = Mock()
-        existing_olt.enacted = 1
-        existing_olt.updated = 2
-
-        with patch.object(VOLTService.objects, "all") as olt_service_mock, \
-                patch.object(OLTDevice.objects, "get") as mock_get, \
-                patch.object(existing_olt, "save") as  mock_save:
-            olt_service_mock.return_value = [self.volt_service]
-            mock_get.return_value = existing_olt
-
-            m.get("http://voltha_url:1234/api/v1/devices", status_code=200, json=self.devices)
-            m.get("http://voltha_url:1234/api/v1/logical_devices", status_code=200, json=self.logical_devices)
-
-            self.sync_step().pull_records()
-
-            mock_save.assert_not_called()
 
 if __name__ == "__main__":
     unittest.main()
\ No newline at end of file
diff --git a/xos/synchronizer/steps/sync_volt_service_instance.py b/xos/synchronizer/steps/sync_volt_service_instance.py
index 98a5b92..2598f60 100644
--- a/xos/synchronizer/steps/sync_volt_service_instance.py
+++ b/xos/synchronizer/steps/sync_volt_service_instance.py
@@ -20,7 +20,7 @@
 import requests
 from multistructlog import create_logger
 from requests.auth import HTTPBasicAuth
-from synchronizers.new_base.modelaccessor import VOLTService, VOLTServiceInstance, ServiceInstance, ONUDevice, model_accessor
+from synchronizers.new_base.modelaccessor import VOLTService, VOLTServiceInstance, ServiceInstance, model_accessor
 from synchronizers.new_base.syncstep import SyncStep, DeferredException
 from xosconfig import Config
 
@@ -41,14 +41,10 @@
 
         c_tag = si.get_westbound_service_instance_properties("c_tag")
 
-        # TODO understand if this can have a better modeling (VOLTHA should know this info for an ONU without manually inserting it in the subscriber)
-        uni_port_id = si.get_westbound_service_instance_properties("uni_port_id")
+        olt_device = o.onu_device.pon_port.olt_device
 
-        onu_device_name = si.get_westbound_service_instance_properties("onu_device")
-
-        onu_device = ONUDevice.objects.get(serial_number=onu_device_name)
-
-        olt_device = onu_device.pon_port.olt_device
+        # NOTE each ONU has only one UNI port!
+        uni_port_id = o.onu_device.uni_ports.first().port_no
 
         if not olt_device.dp_id:
             raise DeferredException("Waiting for OLTDevice %s to be synchronized" % olt_device.name)
diff --git a/xos/synchronizer/steps/test_sync_volt_service_instance.py b/xos/synchronizer/steps/test_sync_volt_service_instance.py
index da77395..6fc377a 100644
--- a/xos/synchronizer/steps/test_sync_volt_service_instance.py
+++ b/xos/synchronizer/steps/test_sync_volt_service_instance.py
@@ -76,12 +76,6 @@
 
         self.sync_step = SyncVOLTServiceInstance
 
-        # create a mock service instance
-        o = Mock()
-        o.id = 1
-        o.owner_id = "volt_service"
-        o.tologdict.return_value = {}
-
         volt_service = Mock()
         volt_service.onos_voltha_url = "onos_voltha_url"
         volt_service.onos_voltha_port = 4321
@@ -91,10 +85,21 @@
         si = Mock()
         si.get_westbound_service_instance_properties = mock_get_westbound_service_instance_properties
 
+        uni_port = Mock()
+        uni_port.port_no = "uni_port_id"
+
         onu_device = Mock()
         onu_device.name = "BRCM1234"
         onu_device.pon_port.olt_device.dp_id = None
         onu_device.pon_port.olt_device.name = "Test OLT Device"
+        onu_device.uni_ports.first.return_value = uni_port
+
+        # create a mock service instance
+        o = Mock()
+        o.id = 1
+        o.owner_id = "volt_service"
+        o.onu_device = onu_device
+        o.tologdict.return_value = {}
 
         self.o = o
         self.si = si
@@ -110,10 +115,8 @@
         self.onu_device.pon_port.olt_device.dp_id = None
 
         with patch.object(ServiceInstance.objects, "get") as service_instance_mock, \
-                patch.object(ONUDevice.objects, "get") as onu_device_mock, \
                 patch.object(VOLTService.objects, "get") as olt_service_mock:
             service_instance_mock.return_value = self.si
-            onu_device_mock.return_value = self.onu_device
             olt_service_mock.return_value = self.volt_service
 
             with self.assertRaises(DeferredException) as e:
@@ -129,10 +132,8 @@
         self.onu_device.pon_port.olt_device.dp_id = "of:dp_id"
 
         with patch.object(ServiceInstance.objects, "get") as service_instance_mock, \
-                patch.object(ONUDevice.objects, "get") as onu_device_mock, \
                 patch.object(VOLTService.objects, "get") as olt_service_mock:
             service_instance_mock.return_value = self.si
-            onu_device_mock.return_value = self.onu_device
             olt_service_mock.return_value = self.volt_service
 
             self.sync_step().sync_record(self.o)
@@ -145,10 +146,8 @@
         self.onu_device.pon_port.olt_device.dp_id = "of:dp_id"
 
         with patch.object(ServiceInstance.objects, "get") as service_instance_mock, \
-                patch.object(ONUDevice.objects, "get") as onu_device_mock, \
                 patch.object(VOLTService.objects, "get") as olt_service_mock:
             service_instance_mock.return_value = self.si
-            onu_device_mock.return_value = self.onu_device
             olt_service_mock.return_value = self.volt_service
 
             with self.assertRaises(Exception) as e: