Imported 18.06.1

1 files changed, 417 insertions, 0 deletions

diff --git a/srsepc/src/mme/s1ap_ctx_mngmt_proc.cc b/srsepc/src/mme/s1ap_ctx_mngmt_proc.cc
new file mode 100644
index 0000000..b9d599d
--- /dev/null
+++ b/srsepc/src/mme/s1ap_ctx_mngmt_proc.cc
@@ -0,0 +1,417 @@
+/**
+ *
+ * \section COPYRIGHT
+ *
+ * Copyright 2013-2017 Software Radio Systems Limited
+ *
+ * \section LICENSE
+ *
+ * This file is part of srsLTE.
+ *
+ * srsLTE is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * srsLTE 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 Affero General Public License for more details.
+ *
+ * A copy of the GNU Affero General Public License can be found in
+ * the LICENSE file in the top-level directory of this distribution
+ * and at http://www.gnu.org/licenses/.
+ *
+ */
+
+//#include "srslte/upper/s1ap_common.h"
+#include "srslte/common/bcd_helpers.h"
+#include "srsepc/hdr/mme/s1ap.h"
+#include "srsepc/hdr/mme/s1ap_ctx_mngmt_proc.h"
+#include "srslte/common/liblte_security.h"
+
+
+namespace srsepc{
+
+s1ap_ctx_mngmt_proc*          s1ap_ctx_mngmt_proc::m_instance = NULL;
+pthread_mutex_t s1ap_ctx_mngmt_proc_instance_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+
+s1ap_ctx_mngmt_proc::s1ap_ctx_mngmt_proc()
+{
+}
+
+s1ap_ctx_mngmt_proc::~s1ap_ctx_mngmt_proc()
+{
+}
+
+s1ap_ctx_mngmt_proc*
+s1ap_ctx_mngmt_proc::get_instance(void)
+{
+  pthread_mutex_lock(&s1ap_ctx_mngmt_proc_instance_mutex);
+  if(NULL == m_instance) {
+    m_instance = new s1ap_ctx_mngmt_proc();
+  }
+  pthread_mutex_unlock(&s1ap_ctx_mngmt_proc_instance_mutex);
+  return(m_instance);
+}
+
+void
+s1ap_ctx_mngmt_proc::cleanup(void)
+{
+  pthread_mutex_lock(&s1ap_ctx_mngmt_proc_instance_mutex);
+  if(NULL != m_instance) {
+    delete m_instance;
+    m_instance = NULL;
+  }
+  pthread_mutex_unlock(&s1ap_ctx_mngmt_proc_instance_mutex);
+}
+
+void
+s1ap_ctx_mngmt_proc::init(void)
+{
+  m_s1ap     = s1ap::get_instance();
+  m_mme_gtpc = mme_gtpc::get_instance();
+  m_s1ap_log = m_s1ap->m_s1ap_log;
+  m_s1ap_args = m_s1ap->m_s1ap_args;
+  m_pool = srslte::byte_buffer_pool::get_instance();
+  m_s1ap_nas_transport = s1ap_nas_transport::get_instance();
+}
+
+bool
+s1ap_ctx_mngmt_proc::send_initial_context_setup_request(ue_emm_ctx_t *emm_ctx,
+                                                        ue_ecm_ctx_t *ecm_ctx,
+                                                        erab_ctx_t *erab_ctx)
+{
+
+  int s1mme = m_s1ap->get_s1_mme();
+
+  //Prepare reply PDU
+  LIBLTE_S1AP_S1AP_PDU_STRUCT pdu;
+  bzero(&pdu, sizeof(LIBLTE_S1AP_S1AP_PDU_STRUCT));
+  pdu.choice_type = LIBLTE_S1AP_S1AP_PDU_CHOICE_INITIATINGMESSAGE;
+
+  LIBLTE_S1AP_INITIATINGMESSAGE_STRUCT *init = &pdu.choice.initiatingMessage;
+  init->procedureCode = LIBLTE_S1AP_PROC_ID_INITIALCONTEXTSETUP;
+  init->choice_type   = LIBLTE_S1AP_INITIATINGMESSAGE_CHOICE_INITIALCONTEXTSETUPREQUEST;
+
+  LIBLTE_S1AP_MESSAGE_INITIALCONTEXTSETUPREQUEST_STRUCT *in_ctxt_req = &init->choice.InitialContextSetupRequest;
+  
+  LIBLTE_S1AP_E_RABTOBESETUPITEMCTXTSUREQ_STRUCT *erab_ctx_req = &in_ctxt_req->E_RABToBeSetupListCtxtSUReq.buffer[0]; //FIXME support more than one erab
+  srslte::byte_buffer_t *reply_buffer = m_pool->allocate(); 
+
+  m_s1ap_log->info("Preparing to send Initial Context Setup request\n");
+
+  //Add MME and eNB S1AP Ids
+  in_ctxt_req->MME_UE_S1AP_ID.MME_UE_S1AP_ID = ecm_ctx->mme_ue_s1ap_id;
+  in_ctxt_req->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID = ecm_ctx->enb_ue_s1ap_id;
+
+  //Set UE-AMBR
+  in_ctxt_req->uEaggregateMaximumBitrate.uEaggregateMaximumBitRateDL.BitRate=1000000000;
+  in_ctxt_req->uEaggregateMaximumBitrate.uEaggregateMaximumBitRateUL.BitRate=1000000000;//FIXME Get UE-AMBR from HSS
+
+  //Setup eRAB context
+  in_ctxt_req->E_RABToBeSetupListCtxtSUReq.len = 1;
+  erab_ctx_req->e_RAB_ID.E_RAB_ID = erab_ctx->erab_id;
+  //Setup E-RAB QoS parameters
+  erab_ctx_req->e_RABlevelQoSParameters.qCI.QCI = erab_ctx->qci;
+  erab_ctx_req->e_RABlevelQoSParameters.allocationRetentionPriority.priorityLevel.PriorityLevel = 15 ;//Lowest
+  erab_ctx_req->e_RABlevelQoSParameters.allocationRetentionPriority.pre_emptionCapability = LIBLTE_S1AP_PRE_EMPTIONCAPABILITY_SHALL_NOT_TRIGGER_PRE_EMPTION;
+  erab_ctx_req->e_RABlevelQoSParameters.allocationRetentionPriority.pre_emptionVulnerability = LIBLTE_S1AP_PRE_EMPTIONVULNERABILITY_PRE_EMPTABLE;
+  erab_ctx_req->e_RABlevelQoSParameters.gbrQosInformation_present=false;
+
+
+  //Set E-RAB S-GW F-TEID
+  //if (cs_resp->eps_bearer_context_created.s1_u_sgw_f_teid_present == false){
+  //  m_s1ap_log->error("Did not receive S1-U TEID in create session response\n");
+  //  return false;
+  //} 
+  erab_ctx_req->transportLayerAddress.n_bits = 32; //IPv4
+  uint32_t sgw_s1u_ip = htonl(erab_ctx->sgw_s1u_fteid.ipv4);
+  //uint32_t sgw_s1u_ip = cs_resp->eps_bearer_context_created.s1_u_sgw_f_teid.ipv4;
+  uint8_t *tmp_ptr =  erab_ctx_req->transportLayerAddress.buffer;
+  liblte_value_2_bits(sgw_s1u_ip, &tmp_ptr, 32);//FIXME consider ipv6
+
+  uint32_t sgw_s1u_teid = erab_ctx->sgw_s1u_fteid.teid; 
+  memcpy(erab_ctx_req->gTP_TEID.buffer, &sgw_s1u_teid, sizeof(uint32_t));
+
+  //Set UE security capabilities and k_enb
+  bzero(in_ctxt_req->UESecurityCapabilities.encryptionAlgorithms.buffer,sizeof(uint8_t)*16); 
+  bzero(in_ctxt_req->UESecurityCapabilities.integrityProtectionAlgorithms.buffer,sizeof(uint8_t)*16); 
+  for(int i = 0; i<3; i++)
+  {
+    if(emm_ctx->security_ctxt.ue_network_cap.eea[i+1] == true)
+    {
+      in_ctxt_req->UESecurityCapabilities.encryptionAlgorithms.buffer[i] = 1;          //EEA supported
+    }
+    else
+    {
+      in_ctxt_req->UESecurityCapabilities.encryptionAlgorithms.buffer[i] = 0;          //EEA not supported
+    }
+    if(emm_ctx->security_ctxt.ue_network_cap.eia[i+1] == true)
+    {
+      in_ctxt_req->UESecurityCapabilities.integrityProtectionAlgorithms.buffer[i] = 1;          //EEA supported
+    }
+    else
+    {
+      in_ctxt_req->UESecurityCapabilities.integrityProtectionAlgorithms.buffer[i] = 0;          //EEA not supported
+    }
+  }
+  //Get K eNB
+  liblte_unpack(emm_ctx->security_ctxt.k_enb, 32, in_ctxt_req->SecurityKey.buffer);
+  m_s1ap_log->info_hex(emm_ctx->security_ctxt.k_enb, 32, "Initial Context Setup Request -- Key eNB (k_enb)\n");
+
+  srslte::byte_buffer_t *nas_buffer = m_pool->allocate();
+  if(emm_ctx->state == EMM_STATE_DEREGISTERED)
+  {
+    //Attach procedure initiated from an attach request
+    m_s1ap_log->console("Adding attach accept to Initial Context Setup Request\n");
+    m_s1ap_log->info("Adding attach accept to Initial Context Setup Request\n");
+    m_s1ap_nas_transport->pack_attach_accept(emm_ctx, ecm_ctx, erab_ctx_req, &erab_ctx->pdn_addr_alloc, nas_buffer); 
+  }
+
+
+  LIBLTE_ERROR_ENUM err = liblte_s1ap_pack_s1ap_pdu(&pdu, (LIBLTE_BYTE_MSG_STRUCT*)reply_buffer);
+  if(err != LIBLTE_SUCCESS)
+  {
+    m_s1ap_log->error("Could not pack Initial Context Setup Request Message\n");
+    return false;
+  }
+
+  //Send Reply to eNB
+  ssize_t n_sent = sctp_send(s1mme,reply_buffer->msg, reply_buffer->N_bytes, &ecm_ctx->enb_sri, 0); 
+  if(n_sent == -1)
+  {
+      m_s1ap_log->error("Failed to send Initial Context Setup Request\n");
+      return false;
+  }
+
+  //Change E-RAB state to Context Setup Requested and save S-GW control F-TEID
+  ecm_ctx->erabs_ctx[erab_ctx_req->e_RAB_ID.E_RAB_ID].state = ERAB_CTX_REQUESTED;
+
+  struct in_addr addr;
+  addr.s_addr = htonl(sgw_s1u_ip);
+  m_s1ap_log->info("Sent Intial Context Setup Request. E-RAB id %d \n",erab_ctx_req->e_RAB_ID.E_RAB_ID);
+  m_s1ap_log->info("Initial Context -- S1-U TEID 0x%x. IP %s \n", sgw_s1u_teid,inet_ntoa(addr));
+  m_s1ap_log->console("Initial Context Setup Request -- eNB UE S1AP Id %d, MME UE S1AP Id %d\n",in_ctxt_req->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID, in_ctxt_req->MME_UE_S1AP_ID.MME_UE_S1AP_ID);
+  m_s1ap_log->console("Initial Context Setup Request -- E-RAB id %d\n",erab_ctx_req->e_RAB_ID.E_RAB_ID);
+  m_s1ap_log->console("Initial Context Setup Request -- S1-U TEID 0x%x. IP %s \n", sgw_s1u_teid,inet_ntoa(addr));
+  m_s1ap_log->console("Initial Context Setup Request -- S1-U TEID 0x%x. IP %s \n", sgw_s1u_teid,inet_ntoa(addr));
+  m_s1ap_log->console("Initial Context Setup Request -- QCI %d \n", erab_ctx_req->e_RABlevelQoSParameters.qCI.QCI);
+
+  m_pool->deallocate(reply_buffer);
+  m_pool->deallocate(nas_buffer);
+  return true;
+}
+
+bool
+s1ap_ctx_mngmt_proc::handle_initial_context_setup_response(LIBLTE_S1AP_MESSAGE_INITIALCONTEXTSETUPRESPONSE_STRUCT *in_ctxt_resp)
+{
+  uint32_t mme_ue_s1ap_id = in_ctxt_resp->MME_UE_S1AP_ID.MME_UE_S1AP_ID;
+  ue_ctx_t *ue_ctx = m_s1ap->find_ue_ctx_from_mme_ue_s1ap_id(mme_ue_s1ap_id);
+  if (ue_ctx == NULL)
+  {
+    m_s1ap_log->error("Could not find UE's context in active UE's map\n");
+    return false;
+  }
+  ue_emm_ctx_t * emm_ctx = &ue_ctx->emm_ctx;
+  ue_ecm_ctx_t * ecm_ctx = &ue_ctx->ecm_ctx;
+
+  m_s1ap_log->console("Received Initial Context Setup Response\n");
+  //Setup E-RABs
+  for(uint32_t i=0; i<in_ctxt_resp->E_RABSetupListCtxtSURes.len;i++)
+  {
+    uint8_t erab_id = in_ctxt_resp->E_RABSetupListCtxtSURes.buffer[i].e_RAB_ID.E_RAB_ID;
+    erab_ctx_t *erab_ctx = &ecm_ctx->erabs_ctx[erab_id];
+    if (erab_ctx->state != ERAB_CTX_REQUESTED)
+    {
+      m_s1ap_log->error("E-RAB requested was not previously requested %d\n",erab_id);
+      return false;
+    }
+    //Mark E-RAB with context setup
+    erab_ctx->state = ERAB_CTX_SETUP;
+
+    //Set the GTP information
+    uint8_t *bit_ptr = in_ctxt_resp->E_RABSetupListCtxtSURes.buffer[i].transportLayerAddress.buffer;
+    erab_ctx->enb_fteid.ipv4 = htonl(liblte_bits_2_value(&bit_ptr,32));
+    memcpy(&erab_ctx->enb_fteid.teid, in_ctxt_resp->E_RABSetupListCtxtSURes.buffer[i].gTP_TEID.buffer, 4);
+    erab_ctx->enb_fteid.teid = ntohl(erab_ctx->enb_fteid.teid);
+
+    char enb_addr_str[INET_ADDRSTRLEN+1];
+    const char *err = inet_ntop(AF_INET, &erab_ctx->enb_fteid.ipv4,enb_addr_str,sizeof(enb_addr_str));
+    if(err == NULL)
+    {
+      m_s1ap_log->error("Error converting IP to string\n");
+    }
+
+    m_s1ap_log->info("E-RAB Context Setup. E-RAB id %d\n",erab_ctx->erab_id);
+    m_s1ap_log->info("E-RAB Context -- eNB TEID 0x%x, eNB Address %s\n", erab_ctx->enb_fteid.teid, enb_addr_str);
+    m_s1ap_log->console("E-RAB Context Setup. E-RAB id %d\n",erab_ctx->erab_id);
+    m_s1ap_log->console("E-RAB Context -- eNB TEID 0x%x; eNB GTP-U Address %s\n", erab_ctx->enb_fteid.teid, enb_addr_str);
+
+  }
+  if(emm_ctx->state == EMM_STATE_REGISTERED)
+  {
+    m_s1ap_log->console("Initial Context Setup Response triggered from Service Request.\n");
+    m_s1ap_log->console("Sending Modify Bearer Request.\n");
+    m_mme_gtpc->send_modify_bearer_request(emm_ctx->imsi, &ecm_ctx->erabs_ctx[5]);
+  }
+  return true;
+}
+
+bool
+s1ap_ctx_mngmt_proc::handle_ue_context_release_request(LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASEREQUEST_STRUCT *ue_rel, struct sctp_sndrcvinfo *enb_sri, srslte::byte_buffer_t *reply_buffer, bool *reply_flag)
+{
+
+  LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASEREQUEST_STRUCT ue_rel_req;
+
+  uint32_t mme_ue_s1ap_id = ue_rel->MME_UE_S1AP_ID.MME_UE_S1AP_ID;
+  m_s1ap_log->info("Received UE Context Release Request. MME-UE S1AP Id: %d\n", mme_ue_s1ap_id);
+  m_s1ap_log->console("Received UE Context Release Request. MME-UE S1AP Id %d\n", mme_ue_s1ap_id);
+
+  ue_ctx_t * ue_ctx = m_s1ap->find_ue_ctx_from_mme_ue_s1ap_id(mme_ue_s1ap_id);
+  if(ue_ctx == NULL)
+  {
+    m_s1ap_log->info("No UE context to release found. MME-UE S1AP Id: %d\n", mme_ue_s1ap_id);
+    m_s1ap_log->console("No UE context to release found. MME-UE S1AP Id: %d\n", mme_ue_s1ap_id);
+    return false;
+  }
+  ue_ecm_ctx_t *ecm_ctx = &ue_ctx->ecm_ctx; 
+
+  //Delete user plane context at the SPGW (but keep GTP-C connection).
+  if (ecm_ctx->state == ECM_STATE_CONNECTED)
+  {
+    //There are active E-RABs, send release access mearers request
+    m_s1ap_log->console("There are active E-RABs, send release access mearers request\n");
+    m_s1ap_log->info("There are active E-RABs, send release access mearers request\n");
+
+    //The handle_release_access_bearers_response function will make sure to mark E-RABS DEACTIVATED
+    //It will release the UEs downstream S1-u and keep the upstream S1-U connection active.
+    m_mme_gtpc->send_release_access_bearers_request(ecm_ctx->imsi);
+
+    //Send release context command to enb, so that it can release it's bearers
+    send_ue_context_release_command(ecm_ctx,reply_buffer);
+  }
+  else
+  {
+    //No ECM Context to release
+    m_s1ap_log->info("UE is not ECM connected. No need to release S1-U. MME UE S1AP Id %d\n", mme_ue_s1ap_id);
+    m_s1ap_log->console("UE is not ECM connected. No need to release S1-U. MME UE S1AP Id %d\n", mme_ue_s1ap_id);
+    //Make sure E-RABS are merked as DEACTIVATED.
+    for(int i=0;i<MAX_ERABS_PER_UE;i++)
+    {
+      ecm_ctx->erabs_ctx[i].state = ERAB_DEACTIVATED;
+    }
+  }
+  
+  //Delete UE context
+  ecm_ctx->state = ECM_STATE_IDLE;
+  ecm_ctx->enb_ue_s1ap_id = 0;
+  ecm_ctx->mme_ue_s1ap_id = 0;
+  m_s1ap_log->info("UE is ECM IDLE.\n");
+  m_s1ap_log->console("UE is ECM IDLE.\n");
+  return true;
+}
+
+bool
+s1ap_ctx_mngmt_proc::send_ue_context_release_command(ue_ecm_ctx_t *ecm_ctx, srslte::byte_buffer_t *reply_buffer)
+{
+
+  int s1mme = m_s1ap->get_s1_mme();
+
+  //Prepare reply PDU
+  LIBLTE_S1AP_S1AP_PDU_STRUCT pdu;
+  bzero(&pdu, sizeof(LIBLTE_S1AP_S1AP_PDU_STRUCT));
+  pdu.choice_type = LIBLTE_S1AP_S1AP_PDU_CHOICE_INITIATINGMESSAGE;
+
+  LIBLTE_S1AP_INITIATINGMESSAGE_STRUCT *init = &pdu.choice.initiatingMessage;
+  init->procedureCode = LIBLTE_S1AP_PROC_ID_UECONTEXTRELEASE;
+  init->choice_type   = LIBLTE_S1AP_INITIATINGMESSAGE_CHOICE_UECONTEXTRELEASECOMMAND;
+
+  LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASECOMMAND_STRUCT *ctx_rel_cmd = &init->choice.UEContextReleaseCommand;
+
+  ctx_rel_cmd->UE_S1AP_IDs.choice_type = LIBLTE_S1AP_UE_S1AP_IDS_CHOICE_UE_S1AP_ID_PAIR;
+  ctx_rel_cmd->UE_S1AP_IDs.choice.uE_S1AP_ID_pair.mME_UE_S1AP_ID.MME_UE_S1AP_ID = ecm_ctx->mme_ue_s1ap_id;
+  ctx_rel_cmd->UE_S1AP_IDs.choice.uE_S1AP_ID_pair.eNB_UE_S1AP_ID.ENB_UE_S1AP_ID = ecm_ctx->enb_ue_s1ap_id;
+
+  ctx_rel_cmd->Cause.choice_type = LIBLTE_S1AP_CAUSE_CHOICE_NAS;
+  ctx_rel_cmd->Cause.choice.nas.ext = false;
+  ctx_rel_cmd->Cause.choice.nas.e =  LIBLTE_S1AP_CAUSENAS_NORMAL_RELEASE;
+
+  LIBLTE_ERROR_ENUM err = liblte_s1ap_pack_s1ap_pdu(&pdu, (LIBLTE_BYTE_MSG_STRUCT*)reply_buffer);
+  if(err != LIBLTE_SUCCESS)
+  {
+    m_s1ap_log->error("Could not pack Initial Context Setup Request Message\n");
+    return false;
+  }
+  //Send Reply to eNB 
+  int n_sent = sctp_send(s1mme,reply_buffer->msg, reply_buffer->N_bytes, &ecm_ctx->enb_sri, 0);
+  if(n_sent == -1)
+  {
+    m_s1ap_log->error("Failed to send Initial Context Setup Request\n");
+    return false;
+  }
+
+
+  return true;
+}
+
+bool
+s1ap_ctx_mngmt_proc::handle_ue_context_release_complete(LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASECOMPLETE_STRUCT *rel_comp)
+{
+  /*
+    typedef struct{
+    bool                                                         ext;
+    LIBLTE_S1AP_MME_UE_S1AP_ID_STRUCT                            MME_UE_S1AP_ID;
+    LIBLTE_S1AP_ENB_UE_S1AP_ID_STRUCT                            eNB_UE_S1AP_ID;
+    LIBLTE_S1AP_CRITICALITYDIAGNOSTICS_STRUCT                    CriticalityDiagnostics;
+    bool                                                         CriticalityDiagnostics_present;
+    LIBLTE_S1AP_USERLOCATIONINFORMATION_STRUCT                   UserLocationInformation;
+    bool                                                         UserLocationInformation_present;
+    }LIBLTE_S1AP_MESSAGE_UECONTEXTRELEASECOMPLETE_STRUCT;
+   */
+
+  uint32_t mme_ue_s1ap_id = rel_comp->MME_UE_S1AP_ID.MME_UE_S1AP_ID;
+  m_s1ap_log->info("Received UE Context Release Complete. MME-UE S1AP Id: %d\n", mme_ue_s1ap_id);
+  m_s1ap_log->console("Received UE Context Release Complete. MME-UE S1AP Id %d\n", mme_ue_s1ap_id);
+
+  ue_ctx_t * ue_ctx = m_s1ap->find_ue_ctx_from_mme_ue_s1ap_id(mme_ue_s1ap_id);
+  if(ue_ctx == NULL)
+  {
+    m_s1ap_log->info("No UE context to release found. MME-UE S1AP Id: %d\n", mme_ue_s1ap_id);
+    m_s1ap_log->console("No UE context to release found. MME-UE S1AP Id: %d\n", mme_ue_s1ap_id);
+    return false;
+  }
+  ue_ecm_ctx_t *ecm_ctx = &ue_ctx->ecm_ctx; 
+
+  //Delete user plane context at the SPGW (but keep GTP-C connection).
+  if (ecm_ctx->state == ECM_STATE_CONNECTED)
+  {
+    //There are active E-RABs, send release access mearers request
+    m_s1ap_log->console("There are active E-RABs, send release access mearers request");
+    m_s1ap_log->info("There are active E-RABs, send release access mearers request");
+    m_mme_gtpc->send_release_access_bearers_request(ecm_ctx->imsi);
+    //The handle_releease_access_bearers_response function will make sure to mark E-RABS DEACTIVATED
+    //It will release the UEs downstream S1-u and keep the upstream S1-U connection active.
+  }
+  else
+  {
+    //No ECM Context to release
+    m_s1ap_log->info("UE is not ECM connected. No need to release S1-U. MME UE S1AP Id %d\n", mme_ue_s1ap_id);
+    m_s1ap_log->console("UE is not ECM connected. No need to release S1-U. MME UE S1AP Id %d\n", mme_ue_s1ap_id);
+    //Make sure E-RABS are merked as DEACTIVATED.
+    for(int i=0;i<MAX_ERABS_PER_UE;i++)
+    {
+      ecm_ctx->erabs_ctx[i].state = ERAB_DEACTIVATED;
+    }
+  }
+
+  //Delete UE context
+  m_s1ap->release_ue_ecm_ctx(ue_ctx->ecm_ctx.mme_ue_s1ap_id);
+  m_s1ap_log->info("UE Context Release Completed.\n");
+  m_s1ap_log->console("UE Context Release Completed.\n");
+  return true;
+}
+
+
+} //namespace srsepc