diff --git a/src/s1ap/handlers/attach_esmreq.c b/src/s1ap/handlers/attach_esmreq.c
new file mode 100644
index 0000000..39f16bb
--- /dev/null
+++ b/src/s1ap/handlers/attach_esmreq.c
@@ -0,0 +1,226 @@
+/*
+ * Copyright (c) 2003-2018, Great Software Laboratory Pvt. Ltd.
+ * Copyright (c) 2017 Intel Corporation
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdint.h>
+
+#include "err_codes.h"
+#include "ipc_api.h"
+#include "main.h"
+#include "msgType.h"
+#include "s1ap.h"
+#include  "log.h"
+#include "snow_3g.h"
+
+/****Globals and externs ***/
+
+/*Making global just to avoid stack passing*/
+static Buffer g_esm_buffer;
+static Buffer g_esm_value_buffer;
+static Buffer g_esm_nas_buffer;
+
+
+/****Global and externs end***/
+extern ipc_handle ipc_S1ap_Hndl;
+/**
+* Get ProtocolIE value for Sec Request sent by mme-app
+*/
+static int
+get_esmreq_protoie_value(struct proto_IE *value, struct esm_req_Q_msg * g_esmReqInfo)
+{
+	value->no_of_IEs = ESM_REQ_NO_OF_IES;
+
+	value->data = (proto_IEs *) malloc(ESM_REQ_NO_OF_IES *
+			sizeof(proto_IEs));
+
+	value->data[0].val.mme_ue_s1ap_id = g_esmReqInfo->ue_idx;
+	value->data[1].val.enb_ue_s1ap_id = g_esmReqInfo->enb_s1ap_ue_id;
+
+	value->data[2].val.nas.header.security_header_type =
+			IntegrityProtectedCiphered;
+
+	value->data[2].val.nas.header.proto_discriminator =
+			EPSMobilityManagementMessages;
+
+	/* placeholder for mac. mac value will be calculated later */
+	uint8_t mac[MAC_SIZE] = {0};
+	memcpy(value->data[2].val.nas.header.mac, mac, MAC_SIZE);
+
+	value->data[2].val.nas.header.seq_no = g_esmReqInfo->dl_seq_no;
+
+	value->data[2].val.nas.header.message_type = ESMInformationRequest;
+
+	/* TODO: Remove hardcoded value */
+	value->data[2].val.nas.header.eps_bearer_identity = 0;
+	value->data[2].val.nas.header.procedure_trans_identity = g_esmReqInfo->pti;
+
+	return SUCCESS;
+}
+
+
+/**
+* Stage specific message processing.
+*/
+static int
+esmreq_processing(struct esm_req_Q_msg * g_esmReqInfo)
+{
+	unsigned char tmpStr[4];
+	struct s1ap_PDU s1apPDU= {0};
+	uint8_t mac_data_pos;
+
+	s1apPDU.procedurecode = id_downlinkNASTransport;
+	s1apPDU.criticality = CRITICALITY_IGNORE;
+
+	get_esmreq_protoie_value(&s1apPDU.value, g_esmReqInfo);
+
+	/* Copy values to g_sec_nas_buffer */
+
+	/* id-NAS-PDU */
+	g_esm_nas_buffer.pos = 0;
+	nasPDU nas = s1apPDU.value.data[2].val.nas;
+
+	unsigned char value = (nas.header.security_header_type << 4 |
+			nas.header.proto_discriminator);
+	buffer_copy(&g_esm_nas_buffer, &value, sizeof(value));
+
+	/* placeholder for mac. mac value will be calculated later */
+	buffer_copy(&g_esm_nas_buffer, &nas.header.mac, MAC_SIZE);
+	mac_data_pos = g_esm_nas_buffer.pos;
+
+	buffer_copy(&g_esm_nas_buffer, &nas.header.seq_no,
+			sizeof(nas.header.seq_no));
+
+	nas.header.proto_discriminator = EPSSessionManagementMessage;
+	value = (nas.header.eps_bearer_identity << 4 |
+				nas.header.proto_discriminator);
+	buffer_copy(&g_esm_nas_buffer, &value, sizeof(value));
+
+	buffer_copy(&g_esm_nas_buffer,
+			&nas.header.procedure_trans_identity,
+			sizeof(nas.header.procedure_trans_identity));
+
+	buffer_copy(&g_esm_nas_buffer, &nas.header.message_type,
+			sizeof(nas.header.message_type));
+
+	/* Calculate mac */
+	uint8_t direction = 1;
+	uint8_t bearer = 0;
+
+	calculate_mac(g_esmReqInfo->int_key, nas.header.seq_no, direction,
+			bearer, &g_esm_nas_buffer.buf[mac_data_pos],
+			g_esm_nas_buffer.pos - mac_data_pos,
+			&g_esm_nas_buffer.buf[mac_data_pos - MAC_SIZE]);
+
+	/* Copy values in g_sec_value_buffer */
+	g_esm_value_buffer.pos = 0;
+
+	/* TODO remove hardcoded values */
+	char chProtoIENo[3] = {0,0,3};
+	buffer_copy(&g_esm_value_buffer, chProtoIENo, 3);
+
+	/* id-MME-UE-S1AP-ID */
+	uint16_t protocolIe_Id = id_MME_UE_S1AP_ID;
+	copyU16(tmpStr, protocolIe_Id);
+	buffer_copy(&g_esm_value_buffer, tmpStr,
+					sizeof(protocolIe_Id));
+
+	unsigned char protocolIe_criticality = CRITICALITY_REJECT;
+	buffer_copy(&g_esm_value_buffer, &protocolIe_criticality,
+					sizeof(protocolIe_criticality));
+
+	unsigned char datalen = 2;
+
+	/* TODO need to add proper handling*/
+	unsigned char mme_ue_id[3];
+	datalen = copyU16(mme_ue_id, s1apPDU.value.data[0].val.mme_ue_s1ap_id);
+	buffer_copy(&g_esm_value_buffer, &datalen, sizeof(datalen));
+	buffer_copy(&g_esm_value_buffer, mme_ue_id, datalen);
+
+	/* id-eNB-UE-S1AP-ID */
+	protocolIe_Id = id_eNB_UE_S1AP_ID;
+	copyU16(tmpStr, protocolIe_Id);
+	buffer_copy(&g_esm_value_buffer, tmpStr,
+						sizeof(protocolIe_Id));
+
+	buffer_copy(&g_esm_value_buffer, &protocolIe_criticality,
+					sizeof(protocolIe_criticality));
+
+	/* TODO needs proper handling*/
+	unsigned char enb_ue_id[3];
+	datalen = copyU16(enb_ue_id, s1apPDU.value.data[1].val.enb_ue_s1ap_id);
+	buffer_copy(&g_esm_value_buffer, &datalen, sizeof(datalen));
+	buffer_copy(&g_esm_value_buffer, enb_ue_id, datalen);
+
+
+	/* id-NAS-PDU */
+	protocolIe_Id = id_NAS_PDU;
+	copyU16(tmpStr, protocolIe_Id);
+	buffer_copy(&g_esm_value_buffer, tmpStr,
+			sizeof(protocolIe_Id));
+
+	buffer_copy(&g_esm_value_buffer, &protocolIe_criticality,
+			sizeof(protocolIe_criticality));
+
+
+	datalen = g_esm_nas_buffer.pos + 1;
+	buffer_copy(&g_esm_value_buffer, &datalen,
+			sizeof(datalen));
+
+	buffer_copy(&g_esm_value_buffer, &g_esm_nas_buffer.pos,
+			sizeof(g_esm_nas_buffer.pos));
+
+	buffer_copy(&g_esm_value_buffer, &g_esm_nas_buffer,
+			g_esm_nas_buffer.pos);
+
+	/* Copy values in g_sec_buffer */
+	g_esm_buffer.pos = 0;
+
+	unsigned char initiating_message = 0; /* TODO: Add enum */
+	buffer_copy(&g_esm_buffer, &initiating_message,
+			sizeof(initiating_message));
+
+	buffer_copy(&g_esm_buffer, &s1apPDU.procedurecode,
+			sizeof(s1apPDU.procedurecode));
+
+	buffer_copy(&g_esm_buffer, &s1apPDU.criticality,
+			sizeof(s1apPDU.criticality));
+
+	buffer_copy(&g_esm_buffer, &g_esm_value_buffer.pos,
+			sizeof(g_esm_value_buffer.pos));
+
+	buffer_copy(&g_esm_buffer, &g_esm_value_buffer,
+			g_esm_value_buffer.pos);
+
+	send_sctp_msg(g_esmReqInfo->enb_fd, g_esm_buffer.buf, g_esm_buffer.pos, 1);
+
+	free(s1apPDU.value.data);
+
+	return SUCCESS;
+}
+
+void*
+esmreq_handler(void *data)
+{
+	log_msg(LOG_INFO, "ESM Info Request handler\n");
+	esmreq_processing((struct esm_req_Q_msg *)data);
+
+	return NULL;
+}