diff --git a/python/adapters/openolt/openolt_flow_mgr.py b/python/adapters/openolt/openolt_flow_mgr.py
new file mode 100644
index 0000000..e298db2
--- /dev/null
+++ b/python/adapters/openolt/openolt_flow_mgr.py
@@ -0,0 +1,1062 @@
+#
+# Copyright 2018 the original author or authors.
+#
+# 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 copy
+from twisted.internet import reactor
+import grpc
+from google.protobuf.json_format import MessageToDict
+import hashlib
+from simplejson import dumps
+
+from voltha.protos.openflow_13_pb2 import OFPXMC_OPENFLOW_BASIC, \
+    ofp_flow_stats, OFPMT_OXM, Flows, FlowGroups, OFPXMT_OFB_IN_PORT, \
+    OFPXMT_OFB_VLAN_VID
+from voltha.protos.device_pb2 import Port
+import voltha.core.flow_decomposer as fd
+from voltha.adapters.openolt.protos import openolt_pb2
+from voltha.registry import registry
+
+from common.tech_profile.tech_profile import DEFAULT_TECH_PROFILE_TABLE_ID
+
+# Flow categories
+HSIA_FLOW = "HSIA_FLOW"
+
+EAP_ETH_TYPE = 0x888e
+LLDP_ETH_TYPE = 0x88cc
+
+IGMP_PROTO = 2
+
+# FIXME - see also BRDCM_DEFAULT_VLAN in broadcom_onu.py
+DEFAULT_MGMT_VLAN = 4091
+
+# Openolt Flow
+UPSTREAM = "upstream"
+DOWNSTREAM = "downstream"
+PACKET_TAG_TYPE = "pkt_tag_type"
+UNTAGGED = "untagged"
+SINGLE_TAG = "single_tag"
+DOUBLE_TAG = "double_tag"
+
+# Classifier
+ETH_TYPE = 'eth_type'
+TPID = 'tpid'
+IP_PROTO = 'ip_proto'
+IN_PORT = 'in_port'
+VLAN_VID = 'vlan_vid'
+VLAN_PCP = 'vlan_pcp'
+UDP_DST = 'udp_dst'
+UDP_SRC = 'udp_src'
+IPV4_DST = 'ipv4_dst'
+IPV4_SRC = 'ipv4_src'
+METADATA = 'metadata'
+OUTPUT = 'output'
+# Action
+POP_VLAN = 'pop_vlan'
+PUSH_VLAN = 'push_vlan'
+TRAP_TO_HOST = 'trap_to_host'
+
+
+class OpenOltFlowMgr(object):
+
+    def __init__(self, adapter_agent, log, stub, device_id, logical_device_id,
+                 platform, resource_mgr):
+        self.adapter_agent = adapter_agent
+        self.log = log
+        self.stub = stub
+        self.device_id = device_id
+        self.logical_device_id = logical_device_id
+        self.nni_intf_id = None
+        self.platform = platform
+        self.logical_flows_proxy = registry('core').get_proxy(
+            '/logical_devices/{}/flows'.format(self.logical_device_id))
+        self.flows_proxy = registry('core').get_proxy(
+            '/devices/{}/flows'.format(self.device_id))
+        self.root_proxy = registry('core').get_proxy('/')
+        self.resource_mgr = resource_mgr
+        self.tech_profile = dict()
+        self._populate_tech_profile_per_pon_port()
+        self.retry_add_flow_list = []
+
+    def add_flow(self, flow):
+        self.log.debug('add flow', flow=flow)
+        classifier_info = dict()
+        action_info = dict()
+
+        for field in fd.get_ofb_fields(flow):
+            if field.type == fd.ETH_TYPE:
+                classifier_info[ETH_TYPE] = field.eth_type
+                self.log.debug('field-type-eth-type',
+                               eth_type=classifier_info[ETH_TYPE])
+            elif field.type == fd.IP_PROTO:
+                classifier_info[IP_PROTO] = field.ip_proto
+                self.log.debug('field-type-ip-proto',
+                               ip_proto=classifier_info[IP_PROTO])
+            elif field.type == fd.IN_PORT:
+                classifier_info[IN_PORT] = field.port
+                self.log.debug('field-type-in-port',
+                               in_port=classifier_info[IN_PORT])
+            elif field.type == fd.VLAN_VID:
+                classifier_info[VLAN_VID] = field.vlan_vid & 0xfff
+                self.log.debug('field-type-vlan-vid',
+                               vlan=classifier_info[VLAN_VID])
+            elif field.type == fd.VLAN_PCP:
+                classifier_info[VLAN_PCP] = field.vlan_pcp
+                self.log.debug('field-type-vlan-pcp',
+                               pcp=classifier_info[VLAN_PCP])
+            elif field.type == fd.UDP_DST:
+                classifier_info[UDP_DST] = field.udp_dst
+                self.log.debug('field-type-udp-dst',
+                               udp_dst=classifier_info[UDP_DST])
+            elif field.type == fd.UDP_SRC:
+                classifier_info[UDP_SRC] = field.udp_src
+                self.log.debug('field-type-udp-src',
+                               udp_src=classifier_info[UDP_SRC])
+            elif field.type == fd.IPV4_DST:
+                classifier_info[IPV4_DST] = field.ipv4_dst
+                self.log.debug('field-type-ipv4-dst',
+                               ipv4_dst=classifier_info[IPV4_DST])
+            elif field.type == fd.IPV4_SRC:
+                classifier_info[IPV4_SRC] = field.ipv4_src
+                self.log.debug('field-type-ipv4-src',
+                               ipv4_dst=classifier_info[IPV4_SRC])
+            elif field.type == fd.METADATA:
+                classifier_info[METADATA] = field.table_metadata
+                self.log.debug('field-type-metadata',
+                               metadata=classifier_info[METADATA])
+            else:
+                raise NotImplementedError('field.type={}'.format(
+                    field.type))
+
+        for action in fd.get_actions(flow):
+            if action.type == fd.OUTPUT:
+                action_info[OUTPUT] = action.output.port
+                self.log.debug('action-type-output',
+                               output=action_info[OUTPUT],
+                               in_port=classifier_info[IN_PORT])
+            elif action.type == fd.POP_VLAN:
+                if fd.get_goto_table_id(flow) is None:
+                    self.log.debug('being taken care of by ONU', flow=flow)
+                    return
+                action_info[POP_VLAN] = True
+                self.log.debug('action-type-pop-vlan',
+                               in_port=classifier_info[IN_PORT])
+            elif action.type == fd.PUSH_VLAN:
+                action_info[PUSH_VLAN] = True
+                action_info[TPID] = action.push.ethertype
+                self.log.debug('action-type-push-vlan',
+                               push_tpid=action_info[TPID], in_port=classifier_info[IN_PORT])
+                if action.push.ethertype != 0x8100:
+                    self.log.error('unhandled-tpid',
+                                   ethertype=action.push.ethertype)
+            elif action.type == fd.SET_FIELD:
+                # action_info['action_type'] = 'set_field'
+                _field = action.set_field.field.ofb_field
+                assert (action.set_field.field.oxm_class ==
+                        OFPXMC_OPENFLOW_BASIC)
+                self.log.debug('action-type-set-field',
+                               field=_field, in_port=classifier_info[IN_PORT])
+                if _field.type == fd.VLAN_VID:
+                    self.log.debug('set-field-type-vlan-vid',
+                                   vlan_vid=_field.vlan_vid & 0xfff)
+                    action_info[VLAN_VID] = (_field.vlan_vid & 0xfff)
+                else:
+                    self.log.error('unsupported-action-set-field-type',
+                                   field_type=_field.type)
+            else:
+                self.log.error('unsupported-action-type',
+                               action_type=action.type, in_port=classifier_info[IN_PORT])
+
+        if fd.get_goto_table_id(flow) is not None and POP_VLAN not in action_info:
+            self.log.debug('being taken care of by ONU', flow=flow)
+            return
+
+        if OUTPUT not in action_info and METADATA in classifier_info:
+            # find flow in the next table
+            next_flow = self.find_next_flow(flow)
+            if next_flow is None:
+                return
+            action_info[OUTPUT] = fd.get_out_port(next_flow)
+            for field in fd.get_ofb_fields(next_flow):
+                if field.type == fd.VLAN_VID:
+                    classifier_info[METADATA] = field.vlan_vid & 0xfff
+
+        self.log.debug('flow-ports', classifier_inport=classifier_info[IN_PORT], action_output=action_info[OUTPUT])
+        (port_no, intf_id, onu_id, uni_id) = self.platform.extract_access_from_flow(
+            classifier_info[IN_PORT], action_info[OUTPUT])
+
+        self.divide_and_add_flow(intf_id, onu_id, uni_id, port_no, classifier_info,
+                                 action_info, flow)
+
+    def _is_uni_port(self, port_no):
+        try:
+            port = self.adapter_agent.get_logical_port(self.logical_device_id,
+                                                       'uni-{}'.format(port_no))
+            if port is not None:
+                return (not port.root_port), port.device_id
+            else:
+                return False, None
+        except Exception as e:
+            self.log.error("error-retrieving-port", e=e)
+            return False, None
+
+    def _clear_flow_id_from_rm(self, flow, flow_id, flow_direction):
+        uni_port_no = None
+        child_device_id = None
+        if flow_direction == UPSTREAM:
+            for field in fd.get_ofb_fields(flow):
+                if field.type == fd.IN_PORT:
+                    is_uni, child_device_id = self._is_uni_port(field.port)
+                    if is_uni:
+                        uni_port_no = field.port
+        elif flow_direction == DOWNSTREAM:
+            for field in fd.get_ofb_fields(flow):
+                if field.type == fd.METADATA:
+                    uni_port = field.table_metadata & 0xFFFFFFFF
+                    is_uni, child_device_id = self._is_uni_port(uni_port)
+                    if is_uni:
+                        uni_port_no = field.port
+
+            if uni_port_no is None:
+                for action in fd.get_actions(flow):
+                    if action.type == fd.OUTPUT:
+                        is_uni, child_device_id = \
+                            self._is_uni_port(action.output.port)
+                        if is_uni:
+                            uni_port_no = action.output.port
+
+        if child_device_id:
+            child_device = self.adapter_agent.get_device(child_device_id)
+            pon_intf = child_device.proxy_address.channel_id
+            onu_id = child_device.proxy_address.onu_id
+            uni_id = self.platform.uni_id_from_port_num(uni_port_no) if uni_port_no is not None else None
+            flows = self.resource_mgr.get_flow_id_info(pon_intf, onu_id, uni_id, flow_id)
+            assert (isinstance(flows, list))
+            self.log.debug("retrieved-flows", flows=flows)
+            for idx in range(len(flows)):
+                if flow_direction == flows[idx]['flow_type']:
+                    flows.pop(idx)
+                    self.update_flow_info_to_kv_store(pon_intf, onu_id, uni_id, flow_id, flows)
+                    if len(flows) > 0:
+                        # There are still flows referencing the same flow_id.
+                        # So the flow should not be freed yet.
+                        # For ex: Case of HSIA where same flow is shared
+                        # between DS and US.
+                        return
+
+            self.resource_mgr.free_flow_id_for_uni(pon_intf, onu_id, uni_id, flow_id)
+        else:
+            self.log.error("invalid-info", uni_port_no=uni_port_no,
+                           child_device_id=child_device_id)
+
+    def retry_add_flow(self, flow):
+        self.log.debug("retry-add-flow")
+        if flow.id in self.retry_add_flow_list:
+            self.retry_add_flow_list.remove(flow.id)
+        self.add_flow(flow)
+
+    def remove_flow(self, flow):
+        self.log.debug('trying to remove flows from logical flow :',
+                       logical_flow=flow)
+        device_flows_to_remove = []
+        device_flows = self.flows_proxy.get('/').items
+        for f in device_flows:
+            if f.cookie == flow.id:
+                device_flows_to_remove.append(f)
+
+        for f in device_flows_to_remove:
+            (id, direction) = self.decode_stored_id(f.id)
+            flow_to_remove = openolt_pb2.Flow(flow_id=id, flow_type=direction)
+            try:
+                self.stub.FlowRemove(flow_to_remove)
+            except grpc.RpcError as grpc_e:
+                if grpc_e.code() == grpc.StatusCode.NOT_FOUND:
+                    self.log.debug('This flow does not exist on the switch, '
+                                   'normal after an OLT reboot',
+                                   flow=flow_to_remove)
+                else:
+                    raise grpc_e
+
+            # once we have successfully deleted the flow on the device
+            # release the flow_id on resource pool and also clear any
+            # data associated with the flow_id on KV store.
+            self._clear_flow_id_from_rm(f, id, direction)
+            self.log.debug('flow removed from device', flow=f,
+                           flow_key=flow_to_remove)
+
+        if len(device_flows_to_remove) > 0:
+            new_flows = []
+            flows_ids_to_remove = [f.id for f in device_flows_to_remove]
+            for f in device_flows:
+                if f.id not in flows_ids_to_remove:
+                    new_flows.append(f)
+
+            self.flows_proxy.update('/', Flows(items=new_flows))
+            self.log.debug('flows removed from the data store',
+                           flow_ids_removed=flows_ids_to_remove,
+                           number_of_flows_removed=(len(device_flows) - len(
+                               new_flows)), expected_flows_removed=len(
+                    device_flows_to_remove))
+        else:
+            self.log.debug('no device flow to remove for this flow (normal '
+                           'for multi table flows)', flow=flow)
+
+    def _get_ofp_port_name(self, intf_id, onu_id, uni_id):
+        parent_port_no = self.platform.intf_id_to_port_no(intf_id, Port.PON_OLT)
+        child_device = self.adapter_agent.get_child_device(self.device_id,
+                                                           parent_port_no=parent_port_no, onu_id=onu_id)
+        if child_device is None:
+            self.log.error("could-not-find-child-device",
+                           parent_port_no=intf_id, onu_id=onu_id)
+            return (None, None)
+        ports = self.adapter_agent.get_ports(child_device.id, Port.ETHERNET_UNI)
+        logical_port = self.adapter_agent.get_logical_port(
+            self.logical_device_id, ports[uni_id].label)
+        ofp_port_name = (logical_port.ofp_port.name, logical_port.ofp_port.port_no)
+        return ofp_port_name
+
+    def get_tp_path(self, intf_id, ofp_port_name):
+        # FIXME Should get Table id form the flow, as of now hardcoded to
+        # DEFAULT_TECH_PROFILE_TABLE_ID (64)
+        # 'tp_path' contains the suffix part of the tech_profile_instance path.
+        # The prefix to the 'tp_path' should be set to \
+        # TechProfile.KV_STORE_TECH_PROFILE_PATH_PREFIX by the ONU adapter.
+        return self.tech_profile[intf_id]. \
+            get_tp_path(DEFAULT_TECH_PROFILE_TABLE_ID,
+                        ofp_port_name)
+
+    def delete_tech_profile_instance(self, intf_id, onu_id, uni_id):
+        # Remove the TP instance associated with the ONU
+        ofp_port_name = self._get_ofp_port_name(intf_id, onu_id, uni_id)
+        tp_path = self.get_tp_path(intf_id, ofp_port_name)
+        return self.tech_profile[intf_id].delete_tech_profile_instance(tp_path)
+
+    def divide_and_add_flow(self, intf_id, onu_id, uni_id, port_no, classifier,
+                            action, flow):
+
+        self.log.debug('sorting flow', intf_id=intf_id, onu_id=onu_id, uni_id=uni_id, port_no=port_no,
+                       classifier=classifier, action=action)
+
+        alloc_id, gem_ports = self.create_tcont_gemport(intf_id, onu_id, uni_id,
+                                                        flow.table_id)
+        if alloc_id is None or gem_ports is None:
+            self.log.error("alloc-id-gem-ports-unavailable", alloc_id=alloc_id,
+                           gem_ports=gem_ports)
+            return
+
+        self.log.debug('Generated required alloc and gemport ids',
+                       alloc_id=alloc_id, gemports=gem_ports)
+
+        # Flows can't be added specific to gemport unless p-bits are received.
+        # Hence adding flows for all gemports
+        for gemport_id in gem_ports:
+            if IP_PROTO in classifier:
+                if classifier[IP_PROTO] == 17:
+                    self.log.debug('dhcp flow add')
+                    self.add_dhcp_trap(intf_id, onu_id, uni_id, port_no, classifier,
+                                       action, flow, alloc_id, gemport_id)
+                elif classifier[IP_PROTO] == 2:
+                    self.log.warn('igmp flow add ignored, not implemented yet')
+                else:
+                    self.log.warn("Invalid-Classifier-to-handle",
+                                  classifier=classifier,
+                                  action=action)
+            elif ETH_TYPE in classifier:
+                if classifier[ETH_TYPE] == EAP_ETH_TYPE:
+                    self.log.debug('eapol flow add')
+                    self.add_eapol_flow(intf_id, onu_id, uni_id, port_no, flow, alloc_id,
+                                        gemport_id)
+                    vlan_id = self.get_subscriber_vlan(fd.get_in_port(flow))
+                    if vlan_id is not None:
+                        self.add_eapol_flow(
+                            intf_id, onu_id, uni_id, port_no, flow, alloc_id, gemport_id,
+                            vlan_id=vlan_id)
+                    parent_port_no = self.platform.intf_id_to_port_no(intf_id, Port.PON_OLT)
+                    onu_device = self.adapter_agent.get_child_device(self.device_id,
+                                                                     onu_id=onu_id,
+                                                                     parent_port_no=parent_port_no)
+                    (ofp_port_name, ofp_port_no) = self._get_ofp_port_name(intf_id, onu_id, uni_id)
+                    if ofp_port_name is None:
+                        self.log.error("port-name-not-found")
+                        return
+
+                    tp_path = self.get_tp_path(intf_id, ofp_port_name)
+
+                    self.log.debug('Load-tech-profile-request-to-brcm-handler',
+                                   tp_path=tp_path)
+                    msg = {'proxy_address': onu_device.proxy_address, 'uni_id': uni_id,
+                           'event': 'download_tech_profile', 'event_data': tp_path}
+
+                    # Send the event message to the ONU adapter
+                    self.adapter_agent.publish_inter_adapter_message(onu_device.id,
+                                                                     msg)
+
+                if classifier[ETH_TYPE] == LLDP_ETH_TYPE:
+                    self.log.debug('lldp flow add')
+                    nni_intf_id = self.get_nni_intf_id()
+                    self.add_lldp_flow(flow, port_no, nni_intf_id)
+
+            elif PUSH_VLAN in action:
+                self.add_upstream_data_flow(intf_id, onu_id, uni_id, port_no, classifier,
+                                            action, flow, alloc_id, gemport_id)
+            elif POP_VLAN in action:
+                self.add_downstream_data_flow(intf_id, onu_id, uni_id, port_no, classifier,
+                                              action, flow, alloc_id, gemport_id)
+            else:
+                self.log.debug('Invalid-flow-type-to-handle',
+                               classifier=classifier,
+                               action=action, flow=flow)
+
+    def create_tcont_gemport(self, intf_id, onu_id, uni_id, table_id):
+        alloc_id, gem_port_ids = None, None
+        pon_intf_onu_id = (intf_id, onu_id)
+
+        # If we already have allocated alloc_id and gem_ports earlier, render them
+        alloc_id = \
+            self.resource_mgr.get_current_alloc_ids_for_onu(pon_intf_onu_id)
+        gem_port_ids = \
+            self.resource_mgr.get_current_gemport_ids_for_onu(pon_intf_onu_id)
+        if alloc_id is not None and gem_port_ids is not None:
+            return alloc_id, gem_port_ids
+
+        try:
+            (ofp_port_name, ofp_port_no) = self._get_ofp_port_name(intf_id, onu_id, uni_id)
+            if ofp_port_name is None:
+                self.log.error("port-name-not-found")
+                return alloc_id, gem_port_ids
+            # FIXME: If table id is <= 63 using 64 as table id
+            if table_id < DEFAULT_TECH_PROFILE_TABLE_ID:
+                table_id = DEFAULT_TECH_PROFILE_TABLE_ID
+
+            # Check tech profile instance already exists for derived port name
+            tech_profile_instance = self.tech_profile[intf_id]. \
+                get_tech_profile_instance(table_id, ofp_port_name)
+            self.log.debug('Get-tech-profile-instance-status', tech_profile_instance=tech_profile_instance)
+
+            if tech_profile_instance is None:
+                # create tech profile instance
+                tech_profile_instance = self.tech_profile[intf_id]. \
+                    create_tech_profile_instance(table_id, ofp_port_name,
+                                                 intf_id)
+                if tech_profile_instance is None:
+                    raise Exception('Tech-profile-instance-creation-failed')
+            else:
+                self.log.debug(
+                    'Tech-profile-instance-already-exist-for-given port-name',
+                    ofp_port_name=ofp_port_name)
+
+            # upstream scheduler
+            us_scheduler = self.tech_profile[intf_id].get_us_scheduler(
+                tech_profile_instance)
+            # downstream scheduler
+            ds_scheduler = self.tech_profile[intf_id].get_ds_scheduler(
+                tech_profile_instance)
+            # create Tcont
+            tconts = self.tech_profile[intf_id].get_tconts(tech_profile_instance,
+                                                           us_scheduler,
+                                                           ds_scheduler)
+
+            self.stub.CreateTconts(openolt_pb2.Tconts(intf_id=intf_id,
+                                                      onu_id=onu_id,
+                                                      uni_id=uni_id,
+                                                      port_no=ofp_port_no,
+                                                      tconts=tconts))
+
+            # Fetch alloc id and gemports from tech profile instance
+            alloc_id = tech_profile_instance.us_scheduler.alloc_id
+            gem_port_ids = []
+            for i in range(len(
+                    tech_profile_instance.upstream_gem_port_attribute_list)):
+                gem_port_ids.append(
+                    tech_profile_instance.upstream_gem_port_attribute_list[i].
+                    gemport_id)
+        except BaseException as e:
+            self.log.exception(exception=e)
+
+        # Update the allocated alloc_id and gem_port_id for the ONU/UNI to KV store
+        pon_intf_onu_id = (intf_id, onu_id, uni_id)
+        self.resource_mgr.resource_mgrs[intf_id].update_alloc_ids_for_onu(
+            pon_intf_onu_id,
+            list([alloc_id])
+        )
+        self.resource_mgr.resource_mgrs[intf_id].update_gemport_ids_for_onu(
+            pon_intf_onu_id,
+            gem_port_ids
+        )
+
+        self.resource_mgr.update_gemports_ponport_to_onu_map_on_kv_store(
+            gem_port_ids, intf_id, onu_id, uni_id
+        )
+
+        return alloc_id, gem_port_ids
+
+    def add_upstream_data_flow(self, intf_id, onu_id, uni_id, port_no, uplink_classifier,
+                               uplink_action, logical_flow, alloc_id,
+                               gemport_id):
+
+        uplink_classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+
+        self.add_hsia_flow(intf_id, onu_id, uni_id, port_no, uplink_classifier,
+                           uplink_action, UPSTREAM,
+                           logical_flow, alloc_id, gemport_id)
+
+        # Secondary EAP on the subscriber vlan
+        (eap_active, eap_logical_flow) = self.is_eap_enabled(intf_id, onu_id, uni_id)
+        if eap_active:
+            self.add_eapol_flow(intf_id, onu_id, uni_id, port_no, eap_logical_flow, alloc_id,
+                                gemport_id, vlan_id=uplink_classifier[VLAN_VID])
+
+    def add_downstream_data_flow(self, intf_id, onu_id, uni_id, port_no, downlink_classifier,
+                                 downlink_action, flow, alloc_id, gemport_id):
+        downlink_classifier[PACKET_TAG_TYPE] = DOUBLE_TAG
+        # Needed ???? It should be already there
+        downlink_action[POP_VLAN] = True
+        downlink_action[VLAN_VID] = downlink_classifier[VLAN_VID]
+
+        self.add_hsia_flow(intf_id, onu_id, uni_id, port_no, downlink_classifier,
+                           downlink_action, DOWNSTREAM,
+                           flow, alloc_id, gemport_id)
+
+    def add_hsia_flow(self, intf_id, onu_id, uni_id, port_no, classifier, action,
+                      direction, logical_flow, alloc_id, gemport_id):
+
+        flow_store_cookie = self._get_flow_store_cookie(classifier,
+                                                        gemport_id)
+
+        # One of the OLT platform (Broadcom BAL) requires that symmetric
+        # flows require the same flow_id to be used across UL and DL.
+        # Since HSIA flow is the only symmetric flow currently, we need to
+        # re-use the flow_id across both direction. The 'flow_category'
+        # takes priority over flow_cookie to find any available HSIA_FLOW
+        # id for the ONU.
+        flow_id = self.resource_mgr.get_flow_id(intf_id, onu_id, uni_id,
+                                                flow_store_cookie,
+                                                HSIA_FLOW)
+        if flow_id is None:
+            self.log.error("hsia-flow-unavailable")
+            return
+        flow = openolt_pb2.Flow(
+            access_intf_id=intf_id, onu_id=onu_id, uni_id=uni_id, flow_id=flow_id,
+            flow_type=direction, alloc_id=alloc_id, network_intf_id=self.get_nni_intf_id(),
+            gemport_id=gemport_id,
+            classifier=self.mk_classifier(classifier),
+            action=self.mk_action(action),
+            priority=logical_flow.priority,
+            port_no=port_no,
+            cookie=logical_flow.cookie)
+
+        if self.add_flow_to_device(flow, logical_flow):
+            flow_info = self._get_flow_info_as_json_blob(flow,
+                                                         flow_store_cookie,
+                                                         HSIA_FLOW)
+            self.update_flow_info_to_kv_store(flow.access_intf_id,
+                                              flow.onu_id, flow.uni_id,
+                                              flow.flow_id, flow_info)
+
+    def add_dhcp_trap(self, intf_id, onu_id, uni_id, port_no, classifier, action, logical_flow,
+                      alloc_id, gemport_id):
+
+        self.log.debug('add dhcp upstream trap', classifier=classifier,
+                       intf_id=intf_id, onu_id=onu_id, uni_id=uni_id, action=action)
+
+        action.clear()
+        action[TRAP_TO_HOST] = True
+        classifier[UDP_SRC] = 68
+        classifier[UDP_DST] = 67
+        classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+        classifier.pop(VLAN_VID, None)
+
+        flow_store_cookie = self._get_flow_store_cookie(classifier,
+                                                        gemport_id)
+
+        flow_id = self.resource_mgr.get_flow_id(
+            intf_id, onu_id, uni_id, flow_store_cookie
+        )
+        dhcp_flow = openolt_pb2.Flow(
+            onu_id=onu_id, uni_id=uni_id, flow_id=flow_id, flow_type=UPSTREAM,
+            access_intf_id=intf_id, gemport_id=gemport_id,
+            alloc_id=alloc_id, network_intf_id=self.get_nni_intf_id(),
+            priority=logical_flow.priority,
+            classifier=self.mk_classifier(classifier),
+            action=self.mk_action(action),
+            port_no=port_no,
+            cookie=logical_flow.cookie)
+
+        if self.add_flow_to_device(dhcp_flow, logical_flow):
+            flow_info = self._get_flow_info_as_json_blob(dhcp_flow, flow_store_cookie)
+            self.update_flow_info_to_kv_store(dhcp_flow.access_intf_id,
+                                              dhcp_flow.onu_id,
+                                              dhcp_flow.uni_id,
+                                              dhcp_flow.flow_id,
+                                              flow_info)
+
+    def add_eapol_flow(self, intf_id, onu_id, uni_id, port_no, logical_flow, alloc_id,
+                       gemport_id, vlan_id=DEFAULT_MGMT_VLAN):
+
+        uplink_classifier = dict()
+        uplink_classifier[ETH_TYPE] = EAP_ETH_TYPE
+        uplink_classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+        uplink_classifier[VLAN_VID] = vlan_id
+
+        uplink_action = dict()
+        uplink_action[TRAP_TO_HOST] = True
+
+        flow_store_cookie = self._get_flow_store_cookie(uplink_classifier,
+                                                        gemport_id)
+        # Add Upstream EAPOL Flow.
+        uplink_flow_id = self.resource_mgr.get_flow_id(
+            intf_id, onu_id, uni_id, flow_store_cookie
+        )
+
+        upstream_flow = openolt_pb2.Flow(
+            access_intf_id=intf_id, onu_id=onu_id, uni_id=uni_id, flow_id=uplink_flow_id,
+            flow_type=UPSTREAM, alloc_id=alloc_id, network_intf_id=self.get_nni_intf_id(),
+            gemport_id=gemport_id,
+            classifier=self.mk_classifier(uplink_classifier),
+            action=self.mk_action(uplink_action),
+            priority=logical_flow.priority,
+            port_no=port_no,
+            cookie=logical_flow.cookie)
+
+        logical_flow = copy.deepcopy(logical_flow)
+        logical_flow.match.oxm_fields.extend(fd.mk_oxm_fields([fd.vlan_vid(
+            vlan_id | 0x1000)]))
+        logical_flow.match.type = OFPMT_OXM
+
+        if self.add_flow_to_device(upstream_flow, logical_flow):
+            flow_info = self._get_flow_info_as_json_blob(upstream_flow,
+                                                         flow_store_cookie)
+            self.update_flow_info_to_kv_store(upstream_flow.access_intf_id,
+                                              upstream_flow.onu_id,
+                                              upstream_flow.uni_id,
+                                              upstream_flow.flow_id,
+                                              flow_info)
+
+        if vlan_id == DEFAULT_MGMT_VLAN:
+            # Add Downstream EAPOL Flow, Only for first EAP flow (BAL
+            # requirement)
+            # On one of the platforms (Broadcom BAL), when same DL classifier
+            # vlan was used across multiple ONUs, eapol flow re-adds after
+            # flow delete (cases of onu reboot/disable) fails.
+            # In order to generate unique vlan, a combination of intf_id
+            # onu_id and uni_id is used.
+            # uni_id defaults to 0, so add 1 to it.
+            special_vlan_downstream_flow = 4090 - intf_id * onu_id * (uni_id+1)
+            # Assert that we do not generate invalid vlans under no condition
+            assert (special_vlan_downstream_flow >= 2, 'invalid-vlan-generated')
+
+            downlink_classifier = dict()
+            downlink_classifier[PACKET_TAG_TYPE] = SINGLE_TAG
+            downlink_classifier[VLAN_VID] = special_vlan_downstream_flow
+
+            downlink_action = dict()
+            downlink_action[PUSH_VLAN] = True
+            downlink_action[VLAN_VID] = vlan_id
+
+
+            flow_store_cookie = self._get_flow_store_cookie(downlink_classifier,
+                                                            gemport_id)
+
+            downlink_flow_id = self.resource_mgr.get_flow_id(
+                intf_id, onu_id, uni_id, flow_store_cookie
+            )
+
+            downstream_flow = openolt_pb2.Flow(
+                access_intf_id=intf_id, onu_id=onu_id, uni_id=uni_id, flow_id=downlink_flow_id,
+                flow_type=DOWNSTREAM, alloc_id=alloc_id, network_intf_id=self.get_nni_intf_id(),
+                gemport_id=gemport_id,
+                classifier=self.mk_classifier(downlink_classifier),
+                action=self.mk_action(downlink_action),
+                priority=logical_flow.priority,
+                port_no=port_no,
+                cookie=logical_flow.cookie)
+
+            downstream_logical_flow = ofp_flow_stats(
+                id=logical_flow.id, cookie=logical_flow.cookie,
+                table_id=logical_flow.table_id, priority=logical_flow.priority,
+                flags=logical_flow.flags)
+
+            downstream_logical_flow.match.oxm_fields.extend(fd.mk_oxm_fields([
+                fd.in_port(fd.get_out_port(logical_flow)),
+                fd.vlan_vid(special_vlan_downstream_flow | 0x1000)]))
+            downstream_logical_flow.match.type = OFPMT_OXM
+
+            downstream_logical_flow.instructions.extend(
+                fd.mk_instructions_from_actions([fd.output(
+                    self.platform.mk_uni_port_num(intf_id, onu_id, uni_id))]))
+
+            if self.add_flow_to_device(downstream_flow, downstream_logical_flow):
+                flow_info = self._get_flow_info_as_json_blob(downstream_flow,
+                                                             flow_store_cookie)
+                self.update_flow_info_to_kv_store(downstream_flow.access_intf_id,
+                                                  downstream_flow.onu_id,
+                                                  downstream_flow.uni_id,
+                                                  downstream_flow.flow_id,
+                                                  flow_info)
+
+    def repush_all_different_flows(self):
+        # Check if the device is supposed to have flows, if so add them
+        # Recover static flows after a reboot
+        logical_flows = self.logical_flows_proxy.get('/').items
+        devices_flows = self.flows_proxy.get('/').items
+        logical_flows_ids_provisioned = [f.cookie for f in devices_flows]
+        for logical_flow in logical_flows:
+            try:
+                if logical_flow.id not in logical_flows_ids_provisioned:
+                    self.add_flow(logical_flow)
+            except Exception as e:
+                self.log.exception('Problem reading this flow', e=e)
+
+    def reset_flows(self):
+        self.flows_proxy.update('/', Flows())
+
+    """ Add a downstream LLDP trap flow on the NNI interface
+    """
+
+    def add_lldp_flow(self, logical_flow, port_no, network_intf_id=0):
+
+        classifier = dict()
+        classifier[ETH_TYPE] = LLDP_ETH_TYPE
+        classifier[PACKET_TAG_TYPE] = UNTAGGED
+        action = dict()
+        action[TRAP_TO_HOST] = True
+
+        # LLDP flow is installed to trap LLDP packets on the NNI port.
+        # We manage flow_id resource pool on per PON port basis.
+        # Since this situation is tricky, as a hack, we pass the NNI port
+        # index (network_intf_id) as PON port Index for the flow_id resource
+        # pool. Also, there is no ONU Id available for trapping LLDP packets
+        # on NNI port, use onu_id as -1 (invalid)
+        # ****************** CAVEAT *******************
+        # This logic works if the NNI Port Id falls within the same valid
+        # range of PON Port Ids. If this doesn't work for some OLT Vendor
+        # we need to have a re-look at this.
+        # *********************************************
+        onu_id = -1
+        uni_id = -1
+        flow_store_cookie = self._get_flow_store_cookie(classifier)
+        flow_id = self.resource_mgr.get_flow_id(network_intf_id, onu_id, uni_id,
+                                                flow_store_cookie)
+
+        downstream_flow = openolt_pb2.Flow(
+            access_intf_id=-1,  # access_intf_id not required
+            onu_id=onu_id, # onu_id not required
+            uni_id=uni_id, # uni_id not used
+            flow_id=flow_id,
+            flow_type=DOWNSTREAM,
+            network_intf_id=network_intf_id,
+            gemport_id=-1,  # gemport_id not required
+            classifier=self.mk_classifier(classifier),
+            action=self.mk_action(action),
+            priority=logical_flow.priority,
+            port_no=port_no,
+            cookie=logical_flow.cookie)
+
+        self.log.debug('add lldp downstream trap', classifier=classifier,
+                       action=action, flow=downstream_flow, port_no=port_no)
+        if self.add_flow_to_device(downstream_flow, logical_flow):
+            self.update_flow_info_to_kv_store(network_intf_id, onu_id, uni_id,
+                                              flow_id, downstream_flow)
+
+    def mk_classifier(self, classifier_info):
+
+        classifier = openolt_pb2.Classifier()
+
+        if ETH_TYPE in classifier_info:
+            classifier.eth_type = classifier_info[ETH_TYPE]
+        if IP_PROTO in classifier_info:
+            classifier.ip_proto = classifier_info[IP_PROTO]
+        if VLAN_VID in classifier_info:
+            classifier.o_vid = classifier_info[VLAN_VID]
+        if METADATA in classifier_info:
+            classifier.i_vid = classifier_info[METADATA]
+        if VLAN_PCP in classifier_info:
+            classifier.o_pbits = classifier_info[VLAN_PCP]
+        if UDP_SRC in classifier_info:
+            classifier.src_port = classifier_info[UDP_SRC]
+        if UDP_DST in classifier_info:
+            classifier.dst_port = classifier_info[UDP_DST]
+        if IPV4_DST in classifier_info:
+            classifier.dst_ip = classifier_info[IPV4_DST]
+        if IPV4_SRC in classifier_info:
+            classifier.src_ip = classifier_info[IPV4_SRC]
+        if PACKET_TAG_TYPE in classifier_info:
+            if classifier_info[PACKET_TAG_TYPE] == SINGLE_TAG:
+                classifier.pkt_tag_type = SINGLE_TAG
+            elif classifier_info[PACKET_TAG_TYPE] == DOUBLE_TAG:
+                classifier.pkt_tag_type = DOUBLE_TAG
+            elif classifier_info[PACKET_TAG_TYPE] == UNTAGGED:
+                classifier.pkt_tag_type = UNTAGGED
+            else:
+                classifier.pkt_tag_type = 'none'
+
+        return classifier
+
+    def mk_action(self, action_info):
+        action = openolt_pb2.Action()
+
+        if POP_VLAN in action_info:
+            action.o_vid = action_info[VLAN_VID]
+            action.cmd.remove_outer_tag = True
+        elif PUSH_VLAN in action_info:
+            action.o_vid = action_info[VLAN_VID]
+            action.cmd.add_outer_tag = True
+        elif TRAP_TO_HOST in action_info:
+            action.cmd.trap_to_host = True
+        else:
+            self.log.info('Invalid-action-field', action_info=action_info)
+            return
+        return action
+
+    def is_eap_enabled(self, intf_id, onu_id, uni_id):
+        flows = self.logical_flows_proxy.get('/').items
+
+        for flow in flows:
+            eap_flow = False
+            eap_intf_id = None
+            eap_onu_id = None
+            eap_uni_id = None
+            for field in fd.get_ofb_fields(flow):
+                if field.type == fd.ETH_TYPE:
+                    if field.eth_type == EAP_ETH_TYPE:
+                        eap_flow = True
+                if field.type == fd.IN_PORT:
+                    eap_intf_id = self.platform.intf_id_from_uni_port_num(
+                        field.port)
+                    eap_onu_id = self.platform.onu_id_from_port_num(field.port)
+                    eap_uni_id = self.platform.uni_id_from_port_num(field.port)
+
+            if eap_flow:
+                self.log.debug('eap flow detected', onu_id=onu_id, uni_id=uni_id,
+                               intf_id=intf_id, eap_intf_id=eap_intf_id,
+                               eap_onu_id=eap_onu_id,
+                               eap_uni_id=eap_uni_id)
+            if eap_flow and intf_id == eap_intf_id and onu_id == eap_onu_id and uni_id == eap_uni_id:
+                return True, flow
+
+        return False, None
+
+    def get_subscriber_vlan(self, port):
+        self.log.debug('looking from subscriber flow for port', port=port)
+
+        flows = self.logical_flows_proxy.get('/').items
+        for flow in flows:
+            in_port = fd.get_in_port(flow)
+            out_port = fd.get_out_port(flow)
+            if in_port == port and out_port is not None and \
+                    self.platform.intf_id_to_port_type_name(out_port) \
+                    == Port.ETHERNET_NNI:
+                fields = fd.get_ofb_fields(flow)
+                self.log.debug('subscriber flow found', fields=fields)
+                for field in fields:
+                    if field.type == OFPXMT_OFB_VLAN_VID:
+                        self.log.debug('subscriber vlan found',
+                                       vlan_id=field.vlan_vid)
+                        return field.vlan_vid & 0x0fff
+        self.log.debug('No subscriber flow found', port=port)
+        return None
+
+    def add_flow_to_device(self, flow, logical_flow):
+        self.log.debug('pushing flow to device', flow=flow)
+        try:
+            self.stub.FlowAdd(flow)
+        except grpc.RpcError as grpc_e:
+            if grpc_e.code() == grpc.StatusCode.ALREADY_EXISTS:
+                self.log.warn('flow already exists', e=grpc_e, flow=flow)
+            else:
+                self.log.error('failed to add flow',
+                               logical_flow=logical_flow, flow=flow,
+                               grpc_error=grpc_e)
+            return False
+        else:
+            self.register_flow(logical_flow, flow)
+            return True
+
+    def update_flow_info_to_kv_store(self, intf_id, onu_id, uni_id, flow_id, flow):
+        self.resource_mgr.update_flow_id_info_for_uni(intf_id, onu_id, uni_id,
+                                                      flow_id, flow)
+
+    def register_flow(self, logical_flow, device_flow):
+        self.log.debug('registering flow in device',
+                       logical_flow=logical_flow, device_flow=device_flow)
+        stored_flow = copy.deepcopy(logical_flow)
+        stored_flow.id = self.generate_stored_id(device_flow.flow_id,
+                                                 device_flow.flow_type)
+        self.log.debug('generated device flow id', id=stored_flow.id,
+                       flow_id=device_flow.flow_id,
+                       direction=device_flow.flow_type)
+        stored_flow.cookie = logical_flow.id
+        flows = self.flows_proxy.get('/')
+        flows.items.extend([stored_flow])
+        self.flows_proxy.update('/', flows)
+
+    def find_next_flow(self, flow):
+        table_id = fd.get_goto_table_id(flow)
+        metadata = 0
+        # Prior to ONOS 1.13.5, Metadata contained the UNI output port number. In
+        # 1.13.5 and later, the lower 32-bits is the output port number and the
+        # upper 32-bits is the inner-vid we are looking for. Use just the lower 32
+        # bits.  Allows this code to work with pre- and post-1.13.5 ONOS OltPipeline
+
+        for field in fd.get_ofb_fields(flow):
+            if field.type == fd.METADATA:
+                metadata = field.table_metadata & 0xFFFFFFFF
+        if table_id is None:
+            return None
+        flows = self.logical_flows_proxy.get('/').items
+        next_flows = []
+        for f in flows:
+            if f.table_id == table_id:
+                # FIXME
+                if fd.get_in_port(f) == fd.get_in_port(flow) and \
+                        fd.get_out_port(f) == metadata:
+                    next_flows.append(f)
+
+        if len(next_flows) == 0:
+            self.log.warning('no next flow found, it may be a timing issue',
+                             flow=flow, number_of_flows=len(flows))
+            if flow.id in self.retry_add_flow_list:
+                self.log.debug('flow is already in retry list', flow_id=flow.id)
+            else:
+                self.retry_add_flow_list.append(flow.id)
+                reactor.callLater(5, self.retry_add_flow, flow)
+            return None
+
+        next_flows.sort(key=lambda f: f.priority, reverse=True)
+
+        return next_flows[0]
+
+    def update_children_flows(self, device_rules_map):
+
+        for device_id, (flows, groups) in device_rules_map.iteritems():
+            if device_id != self.device_id:
+                self.root_proxy.update('/devices/{}/flows'.format(device_id),
+                                       Flows(items=flows.values()))
+                self.root_proxy.update('/devices/{}/flow_groups'.format(
+                    device_id), FlowGroups(items=groups.values()))
+
+    def clear_flows_and_scheduler_for_logical_port(self, child_device, logical_port):
+        ofp_port_name = logical_port.ofp_port.name
+        port_no = logical_port.ofp_port.port_no
+        pon_port = child_device.proxy_address.channel_id
+        onu_id = child_device.proxy_address.onu_id
+        uni_id = self.platform.uni_id_from_port_num(logical_port)
+
+        # TODO: The DEFAULT_TECH_PROFILE_ID is assumed. Right way to do,
+        # is probably to maintain a list of Tech-profile table IDs associated
+        # with the UNI logical_port. This way, when the logical port is deleted,
+        # all the associated tech-profile configuration with the UNI logical_port
+        # can be cleared.
+        tech_profile_instance = self.tech_profile[pon_port]. \
+            get_tech_profile_instance(
+            DEFAULT_TECH_PROFILE_TABLE_ID,
+            ofp_port_name)
+        flow_ids = self.resource_mgr.get_current_flow_ids_for_uni(pon_port, onu_id, uni_id)
+        self.log.debug("outstanding-flows-to-be-cleared", flow_ids=flow_ids)
+        for flow_id in flow_ids:
+            flow_infos = self.resource_mgr.get_flow_id_info(pon_port, onu_id, uni_id, flow_id)
+            for flow_info in flow_infos:
+                direction = flow_info['flow_type']
+                flow_to_remove = openolt_pb2.Flow(flow_id=flow_id,
+                                                  flow_type=direction)
+                try:
+                    self.stub.FlowRemove(flow_to_remove)
+                except grpc.RpcError as grpc_e:
+                    if grpc_e.code() == grpc.StatusCode.NOT_FOUND:
+                        self.log.debug('This flow does not exist on the switch, '
+                                       'normal after an OLT reboot',
+                                       flow=flow_to_remove)
+                    else:
+                        raise grpc_e
+
+                self.resource_mgr.free_flow_id_for_uni(pon_port, onu_id, uni_id, flow_id)
+
+        try:
+            tconts = self.tech_profile[pon_port].get_tconts(tech_profile_instance)
+            self.stub.RemoveTconts(openolt_pb2.Tconts(intf_id=pon_port,
+                                                      onu_id=onu_id,
+                                                      uni_id=uni_id,
+                                                      port_no=port_no,
+                                                      tconts=tconts))
+        except grpc.RpcError as grpc_e:
+            self.log.error('error-removing-tcont-scheduler-queues',
+                           err=grpc_e)
+
+    def generate_stored_id(self, flow_id, direction):
+        if direction == UPSTREAM:
+            self.log.debug('upstream flow, shifting id')
+            return 0x1 << 15 | flow_id
+        elif direction == DOWNSTREAM:
+            self.log.debug('downstream flow, not shifting id')
+            return flow_id
+        else:
+            self.log.warn('Unrecognized direction', direction=direction)
+            return flow_id
+
+    def decode_stored_id(self, id):
+        if id >> 15 == 0x1:
+            return id & 0x7fff, UPSTREAM
+        else:
+            return id, DOWNSTREAM
+
+    def _populate_tech_profile_per_pon_port(self):
+        for arange in self.resource_mgr.device_info.ranges:
+            for intf_id in arange.intf_ids:
+                self.tech_profile[intf_id] = \
+                    self.resource_mgr.resource_mgrs[intf_id].tech_profile
+
+        # Make sure we have as many tech_profiles as there are pon ports on
+        # the device
+        assert len(self.tech_profile) == self.resource_mgr.device_info.pon_ports
+
+    def _get_flow_info_as_json_blob(self, flow, flow_store_cookie,
+                                    flow_category=None):
+        json_blob = MessageToDict(message=flow,
+                                  preserving_proto_field_name=True)
+        self.log.debug("flow-info", json_blob=json_blob)
+        json_blob['flow_store_cookie'] = flow_store_cookie
+        if flow_category is not None:
+            json_blob['flow_category'] = flow_category
+        flow_info = self.resource_mgr.get_flow_id_info(flow.access_intf_id,
+                                                       flow.onu_id, flow.uni_id, flow.flow_id)
+
+        if flow_info is None:
+            flow_info = list()
+            flow_info.append(json_blob)
+        else:
+            assert (isinstance(flow_info, list))
+            flow_info.append(json_blob)
+
+        return flow_info
+
+    @staticmethod
+    def _get_flow_store_cookie(classifier, gem_port=None):
+        assert isinstance(classifier, dict)
+        # We need unique flows per gem_port
+        if gem_port is not None:
+            to_hash = dumps(classifier, sort_keys=True) + str(gem_port)
+        else:
+            to_hash = dumps(classifier, sort_keys=True)
+        return hashlib.md5(to_hash).hexdigest()[:12]
+
+    def get_nni_intf_id(self):
+        if self.nni_intf_id is not None:
+            return self.nni_intf_id
+
+        port_list = self.adapter_agent.get_ports(self.device_id, Port.ETHERNET_NNI)
+        logical_port = self.adapter_agent.get_logical_port(self.logical_device_id,
+                                                           port_list[0].label)
+        self.nni_intf_id = self.platform.intf_id_from_nni_port_num(logical_port.ofp_port.port_no)
+        self.log.debug("nni-intf-d ", nni_intf_id=self.nni_intf_id)
+        return self.nni_intf_id