diff --git a/setup.cfg b/setup.cfg
index 0f861088..28b44c73 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -71,3 +71,5 @@ networking_sfc.flowclassifier.drivers =
     tricircle_fc = tricircle.network.central_fc_driver:TricircleFcDriver
 networking_sfc.sfc.drivers =
     tricircle_sfc = tricircle.network.central_sfc_driver:TricircleSfcDriver
+networking_trunk.trunk.drivers =
+    tricircle_tk = tricircle.network.central_trunk_driver:TricircleTrunkDriver
diff --git a/tricircle/network/central_trunk_driver.py b/tricircle/network/central_trunk_driver.py
new file mode 100644
index 00000000..0e36b3e9
--- /dev/null
+++ b/tricircle/network/central_trunk_driver.py
@@ -0,0 +1,340 @@
+# Copyright 2017 Huawei Technologies Co., Ltd.
+# All Rights Reserved
+#
+#    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.
+
+
+from oslo_log import log
+
+from neutron.services.trunk import exceptions as trunk_exc
+from neutron.services.trunk import plugin as trunk_plugin
+
+import six
+import tricircle.common.client as t_client
+import tricircle.common.constants as t_constants
+import tricircle.common.context as t_context
+from tricircle.common import xrpcapi
+import tricircle.db.api as db_api
+from tricircle.network import helper
+
+LOG = log.getLogger(__name__)
+
+
+class TricircleTrunkDriver(trunk_plugin.TrunkPlugin):
+
+    def __init__(self):
+        super(TricircleTrunkDriver, self).__init__()
+        self.xjob_handler = xrpcapi.XJobAPI()
+        self.helper = helper.NetworkHelper(self)
+        self.clients = {}
+
+    def is_rpc_enabled(self):
+        return False
+
+    def _get_client(self, region_name):
+        if region_name not in self.clients:
+            self.clients[region_name] = t_client.Client(region_name)
+        return self.clients[region_name]
+
+    @property
+    def registered_drivers(self):
+        return super(TricircleTrunkDriver, self).registered_drivers()
+
+    @property
+    def supported_interfaces(self):
+        """A set of supported interfaces."""
+        return super(TricircleTrunkDriver, self).supported_interfaces()
+
+    @property
+    def supported_agent_types(self):
+        """A set of supported agent types."""
+        return super(TricircleTrunkDriver, self).supported_agent_types()
+
+    def update_trunk(self, context, trunk_id, trunk):
+        # update trunk
+        t_ctx = t_context.get_context_from_neutron_context(context)
+        with context.session.begin():
+            res = super(TricircleTrunkDriver, self).update_trunk(
+                context, trunk_id, trunk)
+            mappings = db_api.get_bottom_mappings_by_top_id(
+                t_ctx, trunk_id, t_constants.RT_TRUNK)
+            if mappings:
+                b_pod = mappings[0][0]
+                self.xjob_handler.sync_trunk(t_ctx, res['project_id'],
+                                             trunk_id, b_pod['pod_id'])
+        return res
+
+    def delete_trunk(self, context, trunk_id):
+        t_ctx = t_context.get_context_from_neutron_context(context)
+        res = super(TricircleTrunkDriver, self).get_trunk(
+            context, trunk_id)
+        with context.session.begin():
+            super(TricircleTrunkDriver, self).delete_trunk(
+                context, trunk_id)
+            mappings = db_api.get_bottom_mappings_by_top_id(
+                t_ctx, trunk_id, t_constants.RT_TRUNK)
+            if mappings:
+                b_pod = mappings[0][0]
+                self.xjob_handler.sync_trunk(t_ctx, res['project_id'],
+                                             trunk_id, b_pod['pod_id'])
+
+    def get_trunk(self, context, trunk_id, fields=None):
+        t_ctx = t_context.get_context_from_neutron_context(context)
+        t_trunk = super(TricircleTrunkDriver, self).get_trunk(
+            context, trunk_id, fields)
+        if not fields or 'status' in fields:
+            mappings = db_api.get_bottom_mappings_by_top_id(
+                t_ctx, trunk_id, t_constants.RT_TRUNK)
+            if mappings:
+                b_pod, b_trunk_id = mappings[0]
+                b_region_name = b_pod['region_name']
+                b_client = self._get_client(region_name=b_region_name)
+                b_trunk = b_client.get_trunks(t_ctx, b_trunk_id)
+                if not b_trunk:
+                    LOG.error('trunk: %(trunk_id)s not found '
+                              'pod name: %(name)s',
+                              {'trunk_id': b_trunk_id, 'name': b_region_name})
+                else:
+                    t_trunk['status'] = b_trunk['status']
+
+        return t_trunk
+
+    def _get_trunks_from_top(self, context, top_bottom_map, filters):
+        top_trunks = super(TricircleTrunkDriver, self).get_trunks(
+            context, filters)
+        return [trunk for trunk in top_trunks if
+                trunk['id'] not in top_bottom_map]
+
+    def _get_min_search_step(self):
+        # this method is for unit test mock purpose
+        return 100
+
+    def _get_trunks_from_top_with_limit(self, context, top_bottom_map,
+                                        filters, limit, marker):
+
+        ret = []
+        total = 0
+        # set step as two times of number to have better chance to obtain all
+        # trunks we need
+        search_step = limit * 2
+        min_search_step = self._get_min_search_step()
+        if search_step < min_search_step:
+            search_step = min_search_step
+        # None means sort direction is desc
+        sorts = [('id', None)]
+        top_trunks = super(TricircleTrunkDriver, self).get_trunks(
+            context, filters, sorts=sorts, limit=search_step, marker=marker)
+
+        for trunk in top_trunks:
+            total += 1
+            if trunk['id'] not in top_bottom_map:
+                ret.append(trunk)
+            if len(ret) == limit:
+                return ret
+        # NOTE(xiulin) we have traversed all the trunks
+        if total < search_step:
+            return ret
+        else:
+            ret.extend(self._get_trunks_from_top_with_limit(
+                context, top_bottom_map, filters, limit - len(ret),
+                ret[-1]['id']))
+            return ret
+
+    def _get_trunks_from_pod_with_limit(self, context, current_pod,
+                                        bottom_top_map, top_bottom_map,
+                                        filters, limit, marker):
+
+        ret = []
+        t_ctx = t_context.get_context_from_neutron_context(context)
+        q_client = self._get_client(
+            current_pod['region_name']).get_native_client('trunk', t_ctx)
+
+        params = {'limit': 0 if not limit else limit}
+        if marker:
+            b_marker = top_bottom_map[marker]
+            params.update({'marker': b_marker})
+        if filters:
+            if 'id' in filters:
+                map_ids = self._get_map_trunk_ids(filters['id'],
+                                                  top_bottom_map)
+                filters['id'] = map_ids
+            params.update(filters)
+        bottom_trunks = q_client.get(q_client.trunks_path,
+                                     params=params)['trunks']
+        for bottom_trunk in bottom_trunks:
+            top_id = bottom_top_map.get(bottom_trunk['id'])
+            # TODO(xiulin): handle unmapped trunk
+            if top_id:
+                bottom_trunk['id'] = top_id
+                ret.append(bottom_trunk)
+        if len(ret) == limit:
+            return ret
+
+        remainder = limit - len(ret)
+        next_pod = db_api.get_next_bottom_pod(
+            t_ctx, current_pod_id=current_pod['pod_id'])
+        if next_pod:
+            # get from next bottom pod
+            next_ret = self._get_trunks_from_pod_with_limit(
+                context, next_pod, bottom_top_map, top_bottom_map,
+                filters, remainder, None)
+            ret.extend(next_ret)
+            return ret
+
+    def _map_trunks_from_bottom_to_top(self, trunks, bottom_top_map):
+        trunk_list = []
+        for trunk in trunks:
+            # TODO(xiulin): handle unmapped trunk
+            if trunk['id'] not in bottom_top_map:
+                continue
+            trunk['id'] = bottom_top_map[trunk['id']]
+            trunk_list.append(trunk)
+        return trunk_list
+
+    def _get_map_trunk_ids(self, top_ids, top_bottom_map):
+        b_trunk_ids = []
+        for _id in top_ids:
+            if _id in top_bottom_map:
+                b_trunk_ids.append(top_bottom_map[_id])
+            else:
+                b_trunk_ids.append(_id)
+        return b_trunk_ids
+
+    def _transform_trunk_filters(self, filters, top_bottom_map):
+        _filters = []
+        if filters:
+            for key, value in six.iteritems(filters):
+                if key == 'id':
+                    value = self._get_map_trunk_ids(value, top_bottom_map)
+                _filters.append({'key': key,
+                                 'comparator': 'eq',
+                                 'value': value})
+        return _filters
+
+    def get_trunks(self, context, filters=None, fields=None,
+                   sorts=None, limit=None, marker=None, page_reverse=False):
+        ret = []
+        bottom_top_map = {}
+        top_bottom_map = {}
+        t_ctx = t_context.get_context_from_neutron_context(context)
+
+        route_filters = [{'key': 'resource_type',
+                          'comparator': 'eq',
+                          'value': t_constants.RT_TRUNK}]
+        routes = db_api.list_resource_routings(t_ctx, route_filters)
+        for route in routes:
+            bottom_top_map[route['bottom_id']] = route['top_id']
+            top_bottom_map[route['top_id']] = route['bottom_id']
+
+        if limit:
+            if marker:
+                mappings = db_api.get_bottom_mappings_by_top_id(
+                    t_ctx, marker, t_constants.RT_TRUNK)
+                # if mapping exists, we retrieve trunk information
+                # from bottom, otherwise from top
+                if mappings:
+                    pod_id = mappings[0][0]['pod_id']
+                    current_pod = db_api.get_pod(t_ctx, pod_id)
+                    ret = self._get_trunks_from_pod_with_limit(
+                        context, current_pod, bottom_top_map, top_bottom_map,
+                        filters, limit, marker)
+                else:
+                    ret = self._get_trunks_from_top_with_limit(
+                        context, top_bottom_map, filters, limit, marker)
+            else:
+                current_pod = db_api.get_next_bottom_pod(t_ctx)
+                # if current_pod exists, we retrieve trunk information
+                # from bottom, otherwise from top
+                if current_pod:
+                    ret = self._get_trunks_from_pod_with_limit(
+                        context, current_pod, bottom_top_map, top_bottom_map,
+                        filters, limit, None)
+                else:
+                    ret = self._get_trunks_from_top_with_limit(
+                        context, top_bottom_map, filters, limit, None)
+        else:
+            pods = db_api.list_pods(t_ctx)
+            _filters = self._transform_trunk_filters(filters, top_bottom_map)
+            for pod in pods:
+                if not pod['az_name']:
+                    continue
+                client = self._get_client(pod['region_name'])
+                pod_trunks = client.list_trunks(t_ctx, filters=_filters)
+                ret.extend(pod_trunks)
+            ret = self._map_trunks_from_bottom_to_top(ret, bottom_top_map)
+            top_trunks = self._get_trunks_from_top(context,
+                                                   top_bottom_map, filters)
+            ret.extend(top_trunks)
+
+        return [super(TricircleTrunkDriver, self)._fields(trunk, fields)
+                for trunk in ret]
+
+    def get_trunk_subports(self, context, filters=None):
+        ret = None
+        if not filters or len(filters) != 2:
+            return ret
+        device_ids = filters.get('device_id', [])
+        device_owners = filters.get('device_owner', [])
+        if (len(device_owners) != 1
+           or len(device_ids) != 1
+           or device_owners[0] != t_constants.DEVICE_OWNER_SUBPORT):
+            return ret
+        try:
+            super(TricircleTrunkDriver, self).get_trunk(context, device_ids[0])
+        except trunk_exc.TrunkNotFound:
+            return ret
+
+        ret = super(TricircleTrunkDriver, self).get_ports(context, filters)
+        return ret
+
+    def update_subports_device_id(self, context,
+                                  subports, device_id, device_owner):
+        if not subports['sub_ports']:
+            return
+        body = {'port': {
+            'device_id': device_id,
+            'device_owner': device_owner}}
+        for subport in subports['sub_ports']:
+            super(TricircleTrunkDriver, self).update_port(
+                context, subport['port_id'], body)
+
+    def add_subports(self, context, trunk_id, subports):
+        t_ctx = t_context.get_context_from_neutron_context(context)
+        with context.session.begin():
+            self.update_subports_device_id(context, subports, trunk_id,
+                                           t_constants.DEVICE_OWNER_SUBPORT)
+            res = super(TricircleTrunkDriver, self).add_subports(
+                context, trunk_id, subports)
+            mappings = db_api.get_bottom_mappings_by_top_id(
+                t_ctx, trunk_id, t_constants.RT_TRUNK)
+            if mappings:
+                b_pod = mappings[0][0]
+                self.xjob_handler.sync_trunk(
+                    t_ctx, res['project_id'], trunk_id, b_pod['pod_id'])
+
+        return res
+
+    def remove_subports(self, context, trunk_id, subports):
+        t_ctx = t_context.get_context_from_neutron_context(context)
+        with context.session.begin():
+            self.update_subports_device_id(context, subports, '', '')
+            res = super(TricircleTrunkDriver, self).remove_subports(
+                context, trunk_id, subports)
+            mappings = db_api.get_bottom_mappings_by_top_id(
+                t_ctx, trunk_id, t_constants.RT_TRUNK)
+            if mappings:
+                b_pod = mappings[0][0]
+                self.xjob_handler.sync_trunk(
+                    t_ctx, res['project_id'], trunk_id, b_pod['pod_id'])
+
+        return res
diff --git a/tricircle/network/drivers/openvswitch/__init__.py b/tricircle/network/drivers/openvswitch/__init__.py
new file mode 100644
index 00000000..e69de29b