diff --git a/src/indications.cc b/src/indications.cc
new file mode 100644
index 0000000..78eb3b2
--- /dev/null
+++ b/src/indications.cc
@@ -0,0 +1,413 @@
+/*
+    Copyright (C) 2018 Open Networking Foundation
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+#include "indications.h"
+#include "server.h"
+#include "utils.h"
+extern "C"
+{
+#include <bcmos_system.h>
+#include <bal_api.h>
+#include <bal_api_end.h>
+}
+
+using grpc::Status;
+
+Queue<openolt::Indication> oltIndQ;
+//Queue<openolt::Indication*> oltIndQ;
+
+bool subscribed = false;
+
+bcmos_errno OmciIndication(bcmbal_obj *obj);
+
+bcmos_errno OltIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    openolt::OltIndication* olt_ind = new openolt::OltIndication;
+    Status status;
+
+    bcmbal_access_terminal_ind *acc_term_ind = (bcmbal_access_terminal_ind *)obj;
+    if (acc_term_ind->data.oper_status == BCMBAL_STATUS_UP) {
+        olt_ind->set_oper_state("up");
+    } else {
+        olt_ind->set_oper_state("down");
+    }
+    ind.set_allocated_olt_ind(olt_ind);
+    std::cout << "olt indication, oper_state:" << ind.olt_ind().oper_state() << std::endl;
+    oltIndQ.push(ind);
+
+    // Enable all PON interfaces.
+    for (int i = 0; i < MAX_SUPPORTED_INTF; i++) {
+        status = EnablePonIf_(i);
+        if (!status.ok()) {
+            // FIXME - raise alarm to report error in enabling PON
+        }
+    }
+
+    /* register for omci indication */
+    {
+        bcmbal_cb_cfg cb_cfg = {};
+        uint16_t ind_subgroup;
+
+        cb_cfg.module = BCMOS_MODULE_ID_NONE;
+        cb_cfg.obj_type = BCMBAL_OBJ_ID_PACKET;
+        ind_subgroup = BCMBAL_IND_SUBGROUP(packet, itu_omci_channel_rx);
+        cb_cfg.p_object_key_info = NULL;
+        cb_cfg.p_subgroup = &ind_subgroup;
+        cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OmciIndication;
+        bcmbal_subscribe_ind(0, &cb_cfg);
+    }
+
+    return BCM_ERR_OK;
+}
+
+bcmos_errno LosIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "LOS indication " << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno IfIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    openolt::IntfIndication* intf_ind = new openolt::IntfIndication;
+
+    std::cout << "intf indication, intf_id:"
+              << ((bcmbal_interface_ind *)obj)->key.intf_id << std::endl;
+
+    intf_ind->set_intf_id(((bcmbal_interface_ind *)obj)->key.intf_id);
+    if (((bcmbal_interface_ind *)obj)->data.oper_status == BCMBAL_STATUS_UP) {
+        intf_ind->set_oper_state("up");
+    } else {
+        intf_ind->set_oper_state("down");
+    }
+    ind.set_allocated_intf_ind(intf_ind);
+
+    oltIndQ.push(ind);
+
+    return BCM_ERR_OK;
+}
+
+bcmos_errno IfOperIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    openolt::IntfOperIndication* intf_oper_ind = new openolt::IntfOperIndication;
+    std::cout << "intf oper state indication, intf_id:"
+              << ((bcmbal_interface_ind *)obj)->key.intf_id
+              << " type:" << ((bcmbal_interface_oper_status_change *)obj)->key.intf_type
+              << " oper_state:" << ((bcmbal_interface_oper_status_change *)obj)->data.new_oper_status
+              << " admin_state:" << ((bcmbal_interface_oper_status_change *)obj)->data.admin_state
+              << std::endl;
+
+    intf_oper_ind->set_intf_id(((bcmbal_interface_oper_status_change *)obj)->key.intf_id);
+
+    if (((bcmbal_interface_oper_status_change *)obj)->key.intf_type == BCMBAL_INTF_TYPE_NNI) {
+        intf_oper_ind->set_type("nni");
+    } else if (((bcmbal_interface_oper_status_change *)obj)->key.intf_type == BCMBAL_INTF_TYPE_PON) {
+        intf_oper_ind->set_type("pon");
+    } else {
+        intf_oper_ind->set_type("unknown");
+    }
+
+    if (((bcmbal_interface_oper_status_change *)obj)->data.new_oper_status == BCMBAL_STATUS_UP) {
+        intf_oper_ind->set_oper_state("up");
+    } else {
+        intf_oper_ind->set_oper_state("down");
+    }
+
+    ind.set_allocated_intf_oper_ind(intf_oper_ind);
+
+    oltIndQ.push(ind);
+    return BCM_ERR_OK;
+}
+
+bcmos_errno OnuAlarmIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "onu alarm indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno OnuDyingGaspIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "onu dying-gasp indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno OnuDiscoveryIndication(bcmbal_cfg *obj) {
+    openolt::Indication ind;
+    openolt::OnuDiscIndication* onu_disc_ind = new openolt::OnuDiscIndication;
+    openolt::SerialNumber* serial_number = new openolt::SerialNumber;
+
+    bcmbal_subscriber_terminal_key *key =
+        &(((bcmbal_subscriber_terminal_sub_term_disc*)obj)->key);
+
+    bcmbal_subscriber_terminal_sub_term_disc_data *data =
+        &(((bcmbal_subscriber_terminal_sub_term_disc*)obj)->data);
+
+    bcmbal_serial_number *in_serial_number = &(data->serial_number);
+
+    std::cout << "onu discover indication, intf_id:"
+         << key->intf_id
+         << " serial_number:"
+         << serial_number_to_str(in_serial_number) << std::endl;
+
+    onu_disc_ind->set_intf_id(key->intf_id);
+    serial_number->set_vendor_id(reinterpret_cast<const char *>(in_serial_number->vendor_id), 4);
+    serial_number->set_vendor_specific(reinterpret_cast<const char *>(in_serial_number->vendor_specific), 8);
+    onu_disc_ind->set_allocated_serial_number(serial_number);
+    ind.set_allocated_onu_disc_ind(onu_disc_ind);
+
+    oltIndQ.push(ind);
+
+    return BCM_ERR_OK;
+}
+
+bcmos_errno OnuIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    openolt::OnuIndication* onu_ind = new openolt::OnuIndication;
+    openolt::SerialNumber* serial_number = new openolt::SerialNumber;
+
+    bcmbal_subscriber_terminal_key *key =
+        &(((bcmbal_subscriber_terminal_ind*)obj)->key);
+
+    bcmbal_subscriber_terminal_ind_data *data =
+        &(((bcmbal_subscriber_terminal_ind*)obj)->data);
+
+    bcmbal_serial_number *in_serial_number = &(data->serial_number);
+
+    std::cout << "onu indication, intf_id:"
+         << key->intf_id
+         << " serial_number:"
+         << serial_number_to_str(in_serial_number) << std::endl;
+
+    onu_ind->set_intf_id(key->intf_id);
+    onu_ind->set_onu_id(key->sub_term_id);
+    serial_number->set_vendor_id(reinterpret_cast<const char *>(in_serial_number->vendor_id), 4);
+    serial_number->set_vendor_specific(reinterpret_cast<const char *>(in_serial_number->vendor_specific), 8);
+    onu_ind->set_allocated_serial_number(serial_number);
+    ind.set_allocated_onu_ind(onu_ind);
+
+    oltIndQ.push(ind);
+    return BCM_ERR_OK;
+}
+
+bcmos_errno OnuOperIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "onu oper state indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno OmciIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    openolt::OmciIndication* omci_ind = new openolt::OmciIndication;
+    bcmbal_packet_itu_omci_channel_rx *omci_channel =
+        (bcmbal_packet_itu_omci_channel_rx *)obj;
+
+    std::cout << "omci indication" << std::endl;
+
+    omci_ind->set_intf_id(
+        omci_channel->key.packet_send_dest.u.itu_omci_channel.intf_id);
+    omci_ind->set_onu_id(
+        omci_channel->key.packet_send_dest.u.itu_omci_channel.sub_term_id);
+    omci_ind->set_pkt(omci_channel->data.pkt.val, omci_channel->data.pkt.len);
+
+    ind.set_allocated_omci_ind(omci_ind);
+    oltIndQ.push(ind);
+
+    return BCM_ERR_OK;
+}
+
+bcmos_errno PacketInIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "packet-in indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno FlowOperIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "flow oper state indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno FlowIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "flow indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno TmQIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "traffic mgmt queue indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno TmSchedIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "traffic mgmt sheduler indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+bcmos_errno McastGroupIndication(bcmbal_obj *obj) {
+    openolt::Indication ind;
+    std::cout << "mcast group indication" << std::endl;
+    return BCM_ERR_OK;
+}
+
+Status SubscribeIndication() {
+    bcmbal_cb_cfg cb_cfg = {};
+    uint16_t ind_subgroup;
+
+    if (subscribed) {
+        return Status::OK;
+    }
+
+    cb_cfg.module = BCMOS_MODULE_ID_NONE;
+
+
+    /* OLT device indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_ACCESS_TERMINAL;
+    ind_subgroup = bcmbal_access_terminal_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OltIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Olt indication subscribe failed");
+    }
+
+    /* Interface LOS indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_INTERFACE;
+    ind_subgroup = bcmbal_interface_auto_id_los;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)LosIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "LOS indication subscribe failed");
+    }
+
+    /* Interface indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_INTERFACE;
+    ind_subgroup = bcmbal_interface_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)IfIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Interface indication subscribe failed");
+    }
+
+    /* Interface operational state change indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_INTERFACE;
+    ind_subgroup = bcmbal_interface_auto_id_oper_status_change;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)IfOperIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Interface operations state change indication subscribe failed");
+    }
+
+    /* onu alarm indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_SUBSCRIBER_TERMINAL;
+    ind_subgroup = bcmbal_subscriber_terminal_auto_id_sub_term_alarm;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OnuAlarmIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "onu alarm indication subscribe failed");
+    }
+
+    /* onu dying-gasp indication  */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_SUBSCRIBER_TERMINAL;
+    ind_subgroup = bcmbal_subscriber_terminal_auto_id_dgi;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OnuDyingGaspIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "onu dying-gasp indication subscribe failed");
+    }
+
+    /* onu discovery indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_SUBSCRIBER_TERMINAL;
+    ind_subgroup = bcmbal_subscriber_terminal_auto_id_sub_term_disc;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OnuDiscoveryIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "onu discovery indication subscribe failed");
+    }
+
+    /* onu indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_SUBSCRIBER_TERMINAL;
+    ind_subgroup = bcmbal_subscriber_terminal_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OnuIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "onu indication subscribe failed");
+    }
+    /* onu operational state change indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_SUBSCRIBER_TERMINAL;
+    ind_subgroup = bcmbal_subscriber_terminal_auto_id_oper_status_change;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)OnuOperIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "onu operational state change indication subscribe failed");
+    }
+
+    /* Packet-in indications */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_PACKET;
+    ind_subgroup = bcmbal_packet_auto_id_bearer_channel_rx;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)PacketInIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Packet-in indication subscribe failed");
+    }
+
+    /* Flow Operational State Change */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_FLOW;
+    ind_subgroup = bcmbal_flow_auto_id_oper_status_change;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)FlowOperIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Flow operational state change indication subscribe failed");
+    }
+    /* Flow Indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_FLOW;
+    ind_subgroup = bcmbal_flow_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)FlowIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Flow indication subscribe failed");
+    }
+
+    /* TM queue indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_TM_QUEUE;
+    ind_subgroup = bcmbal_tm_queue_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)TmQIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Traffic mgmt queue indication subscribe failed");
+    }
+
+    /* TM sched indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_TM_SCHED;
+    ind_subgroup = bcmbal_tm_sched_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)TmSchedIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Traffic mgmt queue indication subscribe failed");
+    }
+
+    /* Multicast group indication */
+    cb_cfg.obj_type = BCMBAL_OBJ_ID_GROUP;
+    ind_subgroup = bcmbal_group_auto_id_ind;
+    cb_cfg.p_subgroup = &ind_subgroup;
+    cb_cfg.ind_cb_hdlr = (f_bcmbal_ind_handler)McastGroupIndication;
+    if (BCM_ERR_OK != bcmbal_subscribe_ind(DEFAULT_ATERM_ID, &cb_cfg)) {
+        return Status(grpc::StatusCode::INTERNAL, "Multicast group indication subscribe failed");
+    }
+
+    subscribed = true;
+
+    return Status::OK;
+}