diff --git a/xos/synchronizer/models/models.py b/xos/synchronizer/models/models.py
index ed1e062..3dcefae 100644
--- a/xos/synchronizer/models/models.py
+++ b/xos/synchronizer/models/models.py
@@ -46,6 +46,13 @@
     def get_volt_si(self):
         return VOLTServiceInstance.objects.all()
 
+    def save(self, *args, **kwargs):
+
+        if (self.host or self.port) and self.mac_address:
+            raise XOSValidationError("You can't specify both host/port and mac_address for OLTDevice [host=%s, port=%s, mac_address=%s]" % (self.host, self.port, self.mac_address))
+
+        super(OLTDevice, self).save(*args, **kwargs)
+
     def delete(self, *args, **kwargs):
 
         onus = []
diff --git a/xos/synchronizer/models/test_oltdevice_model.py b/xos/synchronizer/models/test_oltdevice_model.py
index 34bf200..5da9583 100644
--- a/xos/synchronizer/models/test_oltdevice_model.py
+++ b/xos/synchronizer/models/test_oltdevice_model.py
@@ -40,13 +40,24 @@
 
         from models import OLTDevice
 
-        print OLTDevice
-
         self.olt_device = OLTDevice()
         self.olt_device.id = None # this is a new model
         self.olt_device.is_new = True
         self.olt_device.device_id = 1234
 
+    def test_create_mac_address(self):
+        from models import OLTDevice
+        olt = OLTDevice()
+
+        olt.host = "1.1.1.1"
+        olt.port = "9101"
+        olt.mac_address = "00:0c:d5:00:05:40"
+
+        with self.assertRaises(Exception) as e:
+            olt.save()
+
+        self.assertEqual(e.exception.message,
+                         "You can't specify both host/port and mac_address for OLTDevice [host=%s, port=%s, mac_address=%s]" % (olt.host, olt.port, olt.mac_address))
 
     def test_delete(self):
         self.olt_device.delete()
diff --git a/xos/synchronizer/models/volt.xproto b/xos/synchronizer/models/volt.xproto
index 39383f4..3106210 100644
--- a/xos/synchronizer/models/volt.xproto
+++ b/xos/synchronizer/models/volt.xproto
@@ -23,8 +23,9 @@
     required manytoone volt_service->VOLTService:volt_devices = 1 [db_index = True, null = False, blank = False];
     optional string name = 2 [help_text = "name of device", max_length = 254, null = True, db_index = False, blank = True, unique = True];
     required string device_type = 3 [help_text = "Device Type", default = "asfvolt16_olt", max_length = 254, null = False, db_index = False, blank = False, tosca_key=True];
-    required string host = 4 [help_text = "Host", max_length = 254, null = False, db_index = False, blank = False, tosca_key=True];
-    required int32 port = 5 [help_text = "Fabric port", null = False, db_index = False, blank = False, tosca_key=True];
+    optional string host = 4 [help_text = "Device IP", max_length = 254, null = True, db_index = False, blank = True];
+    optional int32 port = 5 [help_text = "Device port", null = True, db_index = False, blank = True, tosca_key_one_of=host];
+    optional string mac_address = 6 [help_text = "Device mac address", null = True, db_index = False, blank = True, tosca_key_one_of=host];
 
     optional string device_id = 10 [help_text = "Device ID", null = True, db_index = False, blank = False, feedback_state = True];
     optional string admin_state = 11 [help_text = "admin_state", null = True, db_index = False, blank = False, feedback_state = True];