Implement PDU session estab through NGAP Initial UE Context Setup

This commit allows the gNB to handle PDU sessions that the core requests
to setup during the NGAP Initial UE Context Setup. Previously, we only
managed them as part of PDU Session Resource Setup Request.

The RRC will, depending on whether a PDU session is in the NGAP Initial
UE Context Setup, either directly trigger the Security Command, or first
do a bearer setup at the CU-UP. Some asserts have been lifted, as now
the PDU sessions might be present before the RRC Connection is fully
established.

Implement the correct forwarding of the bearers in an F1 UE Context
Setup Request message.

This solves bug #672.

openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_direct.c

@@ -69,7 +69,6 @@ static void f1_setup_request_direct(const f1ap_setup_req_t *req)
 static void ue_context_setup_response_direct(const f1ap_ue_context_setup_t *req, const f1ap_ue_context_setup_t *resp)
 {
   DevAssert(req->drbs_to_be_setup_length == resp->drbs_to_be_setup_length);
-  AssertFatal(req->drbs_to_be_setup_length == 0, "not implemented\n");
 
   (void) req; /* we don't need the request -- it is to set up GTP in F1 case */
   MessageDef *msg = itti_alloc_new_message (TASK_MAC_GNB, 0, F1AP_UE_CONTEXT_SETUP_RESP);
@@ -85,6 +84,13 @@ static void ue_context_setup_response_direct(const f1ap_ue_context_setup_t *req,
     for (int i = 0; i < f1ap_msg->srbs_to_be_setup_length; ++i)
       f1ap_msg->srbs_to_be_setup[i] = resp->srbs_to_be_setup[i];
   }
+  if (resp->drbs_to_be_setup_length > 0) {
+    DevAssert(resp->drbs_to_be_setup != NULL);
+    f1ap_msg->drbs_to_be_setup_length = resp->drbs_to_be_setup_length;
+    f1ap_msg->drbs_to_be_setup = calloc(f1ap_msg->drbs_to_be_setup_length, sizeof(*f1ap_msg->drbs_to_be_setup));
+    for (int i = 0; i < f1ap_msg->drbs_to_be_setup_length; ++i)
+      f1ap_msg->drbs_to_be_setup[i] = resp->drbs_to_be_setup[i];
+  }
 
   f1ap_msg->du_to_cu_rrc_information = malloc(sizeof(*resp->du_to_cu_rrc_information));
   AssertFatal(f1ap_msg->du_to_cu_rrc_information != NULL, "out of memory\n");

openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_f1ap.c

@@ -103,7 +103,6 @@ static void f1_setup_request_f1ap(const f1ap_setup_req_t *req)
 static void ue_context_setup_response_f1ap(const f1ap_ue_context_setup_t *req, const f1ap_ue_context_setup_t *resp)
 {
   DevAssert(req->drbs_to_be_setup_length == resp->drbs_to_be_setup_length);
-  AssertFatal(req->drbs_to_be_setup_length == 0, "not implmented\n");
 
   DevAssert(req->srbs_to_be_setup_length == resp->srbs_to_be_setup_length);
   MessageDef *msg = itti_alloc_new_message (TASK_MAC_GNB, 0, F1AP_UE_CONTEXT_SETUP_RESP);
@@ -118,6 +117,13 @@ static void ue_context_setup_response_f1ap(const f1ap_ue_context_setup_t *req, c
     for (int i = 0; i < f1ap_msg->srbs_to_be_setup_length; ++i)
       f1ap_msg->srbs_to_be_setup[i] = resp->srbs_to_be_setup[i];
   }
+  if (resp->drbs_to_be_setup_length > 0) {
+    DevAssert(resp->drbs_to_be_setup != NULL);
+    f1ap_msg->drbs_to_be_setup_length = resp->drbs_to_be_setup_length;
+    f1ap_msg->drbs_to_be_setup = calloc(f1ap_msg->drbs_to_be_setup_length, sizeof(*f1ap_msg->drbs_to_be_setup));
+    for (int i = 0; i < f1ap_msg->drbs_to_be_setup_length; ++i)
+      f1ap_msg->drbs_to_be_setup[i] = resp->drbs_to_be_setup[i];
+  }
 
   f1ap_msg->du_to_cu_rrc_information = malloc(sizeof(*resp->du_to_cu_rrc_information));
   AssertFatal(f1ap_msg->du_to_cu_rrc_information != NULL, "out of memory\n");

openair2/RRC/NR/mac_rrc_dl_f1ap.c

@@ -51,8 +51,20 @@ static void ue_context_setup_request_f1ap(sctp_assoc_t assoc_id, const f1ap_ue_c
   f1ap_ue_context_setup_t *f1ap_msg = &F1AP_UE_CONTEXT_SETUP_REQ(msg);
   *f1ap_msg = *req;
   AssertFatal(req->cu_to_du_rrc_information == NULL, "cu_to_du_rrc_information not supported yet\n");
-  AssertFatal(req->drbs_to_be_setup == NULL, "drbs_to_be_setup not supported yet\n");
-  AssertFatal(req->srbs_to_be_setup == NULL, "drbs_to_be_setup not supported yet\n");
+  if (req->drbs_to_be_setup_length > 0) {
+    int n = req->drbs_to_be_setup_length;
+    f1ap_msg->drbs_to_be_setup_length = n;
+    f1ap_msg->drbs_to_be_setup = calloc(n, sizeof(*f1ap_msg->drbs_to_be_setup));
+    AssertFatal(f1ap_msg->drbs_to_be_setup != NULL, "out of memory\n");
+    memcpy(f1ap_msg->drbs_to_be_setup, req->drbs_to_be_setup, n * sizeof(*f1ap_msg->drbs_to_be_setup));
+  }
+  if (req->srbs_to_be_setup_length > 0) {
+    int n = req->srbs_to_be_setup_length;
+    f1ap_msg->srbs_to_be_setup_length = n;
+    f1ap_msg->srbs_to_be_setup = calloc(n, sizeof(*f1ap_msg->srbs_to_be_setup));
+    AssertFatal(f1ap_msg->srbs_to_be_setup != NULL, "out of memory\n");
+    memcpy(f1ap_msg->srbs_to_be_setup, req->srbs_to_be_setup, n * sizeof(*f1ap_msg->srbs_to_be_setup));
+  }
   if (req->rrc_container_length > 0) {
     f1ap_msg->rrc_container = calloc(req->rrc_container_length, sizeof(*f1ap_msg->rrc_container));
     AssertFatal(f1ap_msg->rrc_container != NULL, "out of memory\n");

openair2/RRC/NR/nr_rrc_proto.h

@@ -81,7 +81,9 @@ int parse_CG_ConfigInfo(gNB_RRC_INST *rrc, NR_CG_ConfigInfo_t *CG_ConfigInfo, x2
 void
 rrc_gNB_generate_SecurityModeCommand(
   const protocol_ctxt_t *const ctxt_pP,
-  rrc_gNB_ue_context_t          *const ue_context_pP
+  rrc_gNB_ue_context_t          *const ue_context_pP,
+  int n_drbs,
+  const f1ap_drb_to_be_setup_t *drbs
 );
 
 unsigned int rrc_gNB_get_next_transaction_identifier(module_id_t gnb_mod_idP);

openair2/RRC/NR/rrc_gNB.c

@@ -509,7 +509,6 @@ static void rrc_gNB_generate_defaultRRCReconfiguration(const protocol_ctxt_t *co
 {
   gNB_RRC_INST *rrc = RC.nrrrc[ctxt_pP->module_id];
   gNB_RRC_UE_t *ue_p = &ue_context_pP->ue_context;
-  AssertFatal(ue_p->nb_of_pdusessions == 0, "logic bug: PDU sessions present before RRC Connection established\n");
   uint8_t xid = rrc_gNB_get_next_transaction_identifier(ctxt_pP->module_id);
   ue_p->xids[xid] = RRC_DEFAULT_RECONF;
 
@@ -551,14 +550,16 @@ static void rrc_gNB_generate_defaultRRCReconfiguration(const protocol_ctxt_t *co
     uint32_t ssb_arfcn = get_ssb_arfcn(cell_info, du->mib, du->sib1);
     measconfig = get_defaultMeasConfig(ssb_arfcn, band, scs);
   }
+  NR_SRB_ToAddModList_t *SRBs = createSRBlist(ue_p, false);
+  NR_DRB_ToAddModList_t *DRBs = createDRBlist(ue_p, false);
 
   uint8_t buffer[RRC_BUF_SIZE] = {0};
   int size = do_RRCReconfiguration(ue_p,
                                    buffer,
                                    RRC_BUF_SIZE,
                                    xid,
-                                   NULL, //*SRB_configList2,
-                                   NULL, //*DRB_configList,
+                                   SRBs,
+                                   DRBs,
                                    NULL,
                                    NULL,
                                    measconfig,
@@ -566,6 +567,8 @@ static void rrc_gNB_generate_defaultRRCReconfiguration(const protocol_ctxt_t *co
                                    ue_p->masterCellGroup);
   AssertFatal(size > 0, "cannot encode RRCReconfiguration in %s()\n", __func__);
   free_defaultMeasConfig(measconfig);
+  freeSRBlist(SRBs);
+  freeDRBlist(DRBs);
 
   if (LOG_DEBUGFLAG(DEBUG_ASN1)) {
     xer_fprint(stdout, &asn_DEF_NR_CellGroupConfig, ue_p->masterCellGroup);
@@ -1759,6 +1762,11 @@ static void rrc_CU_process_ue_context_setup_response(MessageDef *msg_p, instance
   if (LOG_DEBUGFLAG(DEBUG_ASN1))
     xer_fprint(stdout, &asn_DEF_NR_CellGroupConfig, UE->masterCellGroup);
 
+  if (resp->drbs_to_be_setup_length > 0) {
+    AssertFatal(resp->srbs_to_be_setup_length > 0 && resp->srbs_to_be_setup[0].srb_id == 2, "logic bug: we set up DRBs, so need to have both SRB1&SRB2\n");
+    e1_send_bearer_updates(rrc, UE, resp->drbs_to_be_setup_length, resp->drbs_to_be_setup);
+  }
+
   /* at this point, we don't have to do anything: the UE context setup request
    * includes the Security Command, whose response will trigger the following
    * messages (UE capability, to be specific) */
@@ -2006,7 +2014,7 @@ void rrc_gNB_process_e1_bearer_context_setup_resp(e1ap_bearer_setup_resp_t *resp
 
   /* Instruction towards the DU for SRB2 configuration */
   int nb_srb = 0;
-  f1ap_srb_to_be_setup_t srbs[1];
+  f1ap_srb_to_be_setup_t srbs[1] = {0};
   if (UE->Srb[2].Active == 0) {
     activate_srb(UE, 2);
     nb_srb = 1;
@@ -2017,7 +2025,8 @@ void rrc_gNB_process_e1_bearer_context_setup_resp(e1ap_bearer_setup_resp_t *resp
   if (!UE->as_security_active) {
     /* no AS security active, need to send UE context setup req with security
      * command (and the bearers) */
-    AssertFatal(false, "not implemented yet\n");
+    protocol_ctxt_t ctxt = {.rntiMaybeUEid = UE->rrc_ue_id};
+    rrc_gNB_generate_SecurityModeCommand(&ctxt, ue_context_p, nb_drb, drbs);
     return;
   }
 
@@ -2387,7 +2396,9 @@ static void rrc_deliver_ue_ctxt_setup_req(void *deliver_pdu_data, ue_id_t ue_id,
 void
 rrc_gNB_generate_SecurityModeCommand(
   const protocol_ctxt_t *const ctxt_pP,
-  rrc_gNB_ue_context_t  *const ue_context_pP
+  rrc_gNB_ue_context_t  *const ue_context_pP,
+  int n_drbs,
+  const f1ap_drb_to_be_setup_t *drbs
 )
 //-----------------------------------------------------------------------------
 {
@@ -2413,6 +2424,16 @@ rrc_gNB_generate_SecurityModeCommand(
     cu2du.uE_CapabilityRAT_ContainerList_length = ue_p->ue_cap_buffer.len;
   }
 
+  int nb_srb = 0;
+  f1ap_srb_to_be_setup_t srb_buf[1] = {0};
+  f1ap_srb_to_be_setup_t *srbs = 0;
+  if (n_drbs > 0) {
+    nb_srb = 1;
+    srb_buf[0].srb_id = 2;
+    srb_buf[0].lcid = 2;
+    srbs = srb_buf;
+  }
+
   /* the callback will fill the UE context setup request and forward it */
   f1_ue_data_t ue_data = cu_get_f1_ue_data(ue_p->rrc_ue_id);
   RETURN_IF_INVALID_ASSOC_ID(ue_data);
@@ -2424,8 +2445,10 @@ rrc_gNB_generate_SecurityModeCommand(
       .plmn.mnc_digit_length = rrc->configuration.mnc_digit_length[0],
       .nr_cellid = rrc->nr_cellid,
       .servCellId = 0, /* TODO: correct value? */
-      .srbs_to_be_setup = 0, /* no new SRBs */
-      .drbs_to_be_setup = 0, /* no new DRBs */
+      .srbs_to_be_setup_length = nb_srb,
+      .srbs_to_be_setup = srbs,
+      .drbs_to_be_setup_length = n_drbs,
+      .drbs_to_be_setup = (f1ap_drb_to_be_setup_t *) drbs,
       .cu_to_du_rrc_information = cu2du_p,
   };
   deliver_ue_ctxt_setup_data_t data = {.rrc = rrc, .setup_req = &ue_context_setup_req, .assoc_id = ue_data.du_assoc_id };

openair2/RRC/NR/rrc_gNB_NGAP.c

@@ -362,6 +362,111 @@ static int decodePDUSessionResourceSetup(pdusession_t *session)
   return 0;
 }
 
+static void trigger_bearer_setup(gNB_RRC_INST *rrc, gNB_RRC_UE_t *UE, int n, pdusession_t *sessions, uint64_t ueAggMaxBitRateDownlink)
+{
+  e1ap_bearer_setup_req_t bearer_req = {0};
+
+  e1ap_nssai_t cuup_nssai = {0};
+  for (int i = 0; i < n; i++) {
+    rrc_pdu_session_param_t *pduSession = find_pduSession(UE, sessions[i].pdusession_id, true);
+    pdusession_t *session = &pduSession->param;
+    session->pdusession_id = sessions[i].pdusession_id;
+    LOG_I(NR_RRC, "Adding pdusession %d, total nb of sessions %d\n", session->pdusession_id, UE->nb_of_pdusessions);
+    session->pdu_session_type = sessions[i].pdu_session_type;
+    session->nas_pdu = sessions[i].nas_pdu;
+    session->pdusessionTransfer = sessions[i].pdusessionTransfer;
+    session->nssai = sessions[i].nssai;
+    decodePDUSessionResourceSetup(session);
+    bearer_req.gNB_cu_cp_ue_id = UE->rrc_ue_id;
+    bearer_req.cipheringAlgorithm = UE->ciphering_algorithm;
+    bearer_req.integrityProtectionAlgorithm = UE->integrity_algorithm;
+    nr_derive_key(UP_ENC_ALG, UE->ciphering_algorithm, UE->kgnb, (uint8_t *)bearer_req.encryptionKey);
+    nr_derive_key(UP_INT_ALG, UE->integrity_algorithm, UE->kgnb, (uint8_t *)bearer_req.integrityProtectionKey);
+    bearer_req.ueDlAggMaxBitRate = ueAggMaxBitRateDownlink;
+    pdu_session_to_setup_t *pdu = bearer_req.pduSession + bearer_req.numPDUSessions;
+    bearer_req.numPDUSessions++;
+    pdu->sessionId = session->pdusession_id;
+    pdu->nssai = sessions[i].nssai;
+    if (cuup_nssai.sst == 0)
+      cuup_nssai = pdu->nssai; /* for CU-UP selection below */
+
+    pdu->integrityProtectionIndication = rrc->security.do_drb_integrity ? E1AP_IntegrityProtectionIndication_required : E1AP_IntegrityProtectionIndication_not_needed;
+
+    pdu->confidentialityProtectionIndication = rrc->security.do_drb_ciphering ? E1AP_ConfidentialityProtectionIndication_required : E1AP_ConfidentialityProtectionIndication_not_needed;
+    pdu->teId = session->gtp_teid;
+    memcpy(&pdu->tlAddress, session->upf_addr.buffer, 4); // Fixme: dirty IPv4 target
+
+    /* we assume for the moment one DRB per PDU session. Activate the bearer,
+     * and configure in RRC. */
+    int drb_id = get_next_available_drb_id(UE);
+    drb_t *rrc_drb = generateDRB(UE,
+                                 drb_id,
+                                 pduSession,
+                                 rrc->configuration.enable_sdap,
+                                 rrc->security.do_drb_integrity,
+                                 rrc->security.do_drb_ciphering);
+
+    pdu->numDRB2Setup = 1; // One DRB per PDU Session. TODO: Remove hardcoding
+    for (int j=0; j < pdu->numDRB2Setup; j++) {
+      DRB_nGRAN_to_setup_t *drb = pdu->DRBnGRanList + j;
+
+      drb->id = rrc_drb->drb_id;
+
+      struct sdap_config_s *sdap_config = &rrc_drb->cnAssociation.sdap_config;
+      drb->defaultDRB = sdap_config->defaultDRB ? E1AP_DefaultDRB_true : E1AP_DefaultDRB_false;
+      drb->sDAP_Header_UL = sdap_config->sdap_HeaderUL;
+      drb->sDAP_Header_DL = sdap_config->sdap_HeaderDL;
+
+      struct pdcp_config_s *pdcp_config = &rrc_drb->pdcp_config;
+      drb->pDCP_SN_Size_UL = pdcp_config->pdcp_SN_SizeUL;
+      drb->pDCP_SN_Size_DL = pdcp_config->pdcp_SN_SizeDL;
+      drb->discardTimer = pdcp_config->discardTimer;
+      drb->reorderingTimer = pdcp_config->t_Reordering;
+
+      drb->rLC_Mode = rrc->configuration.um_on_default_drb ? E1AP_RLC_Mode_rlc_um_bidirectional : E1AP_RLC_Mode_rlc_am;
+
+      drb->numCellGroups = 1; // assume one cell group associated with a DRB
+
+      for (int k=0; k < drb->numCellGroups; k++) {
+        cell_group_t *cellGroup = drb->cellGroupList + k;
+        cellGroup->id = 0; // MCG
+      }
+
+      drb->numQosFlow2Setup = session->nb_qos;
+      for (int k=0; k < drb->numQosFlow2Setup; k++) {
+        qos_flow_to_setup_t *qos_flow = drb->qosFlows + k;
+        pdusession_level_qos_parameter_t *qos_session = session->qos + k;
+
+        qos_characteristics_t *qos_char = &qos_flow->qos_params.qos_characteristics;
+        qos_flow->qfi = qos_session->qfi;
+        qos_char->qos_type = qos_session->fiveQI_type;
+        if (qos_char->qos_type == dynamic) {
+          qos_char->dynamic.fiveqi = qos_session->fiveQI;
+          qos_char->dynamic.qos_priority_level = qos_session->qos_priority;
+        } else {
+          qos_char->non_dynamic.fiveqi = qos_session->fiveQI;
+          qos_char->non_dynamic.qos_priority_level = qos_session->qos_priority;
+        }
+
+        ngran_allocation_retention_priority_t *rent_priority = &qos_flow->qos_params.alloc_reten_priority;
+        ngap_allocation_retention_priority_t *rent_priority_in = &qos_session->allocation_retention_priority;
+        rent_priority->priority_level = rent_priority_in->priority_level;
+        rent_priority->preemption_capability = rent_priority_in->pre_emp_capability;
+        rent_priority->preemption_vulnerability = rent_priority_in->pre_emp_vulnerability;
+      }
+    }
+  }
+  int xid = rrc_gNB_get_next_transaction_identifier(0);
+  UE->xids[xid] = RRC_PDUSESSION_ESTABLISH;
+  /* Limitation: we assume one fixed CU-UP per UE. We base the selection on
+   * NSSAI, but the UE might have multiple PDU sessions with differing slices,
+   * in which we might need to select different CU-UPs. In this case, we would
+   * actually need to group the E1 bearer context setup for the different
+   * CU-UPs, and send them to the different CU-UPs. */
+  sctp_assoc_t assoc_id = get_new_cuup_for_ue(rrc, UE, cuup_nssai.sst, cuup_nssai.sd);
+  rrc->cucp_cuup.bearer_context_setup(assoc_id, &bearer_req);
+}
+
 //------------------------------------------------------------------------------
 int rrc_gNB_process_NGAP_INITIAL_CONTEXT_SETUP_REQ(MessageDef *msg_p, instance_t instance)
 //------------------------------------------------------------------------------
@@ -384,40 +489,6 @@ int rrc_gNB_process_NGAP_INITIAL_CONTEXT_SETUP_REQ(MessageDef *msg_p, instance_t
   }
   PROTOCOL_CTXT_SET_BY_INSTANCE(&ctxt, instance, GNB_FLAG_YES, UE->rrc_ue_id, 0, 0);
   UE->amf_ue_ngap_id = req->amf_ue_ngap_id;
-  uint8_t nb_pdusessions_tosetup = req->nb_of_pdusessions;
-  if (nb_pdusessions_tosetup) {
-    AssertFatal(false, "PDU sessions in Initial context setup request not handled by E1 yet\n");
-    /* this code should pass by E1: commenting here for future reference, but
-     * already handled in E1 for the "normal case" of a separate request for
-     * PDU session setup.
-    gtpv1u_gnb_create_tunnel_req_t create_tunnel_req = {0};
-    for (int i = 0; i < nb_pdusessions_tosetup; i++) {
-      UE->nb_of_pdusessions++;
-      if(UE->pduSession[i].status >= PDU_SESSION_STATUS_DONE)
-        continue;
-      UE->pduSession[i].status      = PDU_SESSION_STATUS_NEW;
-      UE->pduSession[i].param = req->pdusession_param[i];
-      create_tunnel_req.num_tunnels++;
-      create_tunnel_req.pdusession_id[i] = req->pdusession_param[i].pdusession_id;
-      create_tunnel_req.outgoing_teid[i] = req->pdusession_param[i].gtp_teid;
-      // To be developped: hardcoded first flow
-      create_tunnel_req.outgoing_qfi[i] = req->pdusession_param[i].qos[0].qfi;
-      create_tunnel_req.dst_addr[i].length = req->pdusession_param[i].upf_addr.length;
-      memcpy(create_tunnel_req.dst_addr[i].buffer, req->pdusession_param[i].upf_addr.buffer, sizeof(create_tunnel_req.dst_addr[i].buffer));
-      LOG_I(NR_RRC, "PDUSESSION SETUP: local index %d teid %u, pdusession id %d \n", i, create_tunnel_req.outgoing_teid[i], create_tunnel_req.pdusession_id[i]);
-    }
-    create_tunnel_req.ue_id = UE->rrc_ue_id;
-    gtpv1u_gnb_create_tunnel_resp_t create_tunnel_resp = {0};
-    int ret = gtpv1u_create_ngu_tunnel(instance, &create_tunnel_req, &create_tunnel_resp, nr_pdcp_data_req_drb, sdap_data_req);
-    if (ret != 0) {
-      LOG_E(NR_RRC, "rrc_gNB_process_NGAP_INITIAL_CONTEXT_SETUP_REQ : gtpv1u_create_ngu_tunnel failed,start to release UE %x\n", UE->rnti);
-      AssertFatal(false, "release timer not implemented\n");
-      return (0);
-    }
-
-    nr_rrc_gNB_process_GTPV1U_CREATE_TUNNEL_RESP(&ctxt, &create_tunnel_resp, 0);
-    */
-  }
 
   /* NAS PDU */
   // this is malloced pointers, we pass it for later free()
@@ -430,7 +501,19 @@ int rrc_gNB_process_NGAP_INITIAL_CONTEXT_SETUP_REQ(MessageDef *msg_p, instance_t
   /* configure only integrity, ciphering comes after receiving SecurityModeComplete */
   nr_rrc_pdcp_config_security(&ctxt, ue_context_p, 0);
 
-  rrc_gNB_generate_SecurityModeCommand(&ctxt, ue_context_p);
+  uint8_t nb_pdusessions_tosetup = req->nb_of_pdusessions;
+  /* if there are PDU sessions to setup, first send them to the CU-UP, then
+   * send the UE Context setup with Security commend. Else go to the security
+   * command directly. */
+  if (nb_pdusessions_tosetup > 0) {
+    trigger_bearer_setup(RC.nrrrc[instance],
+                         UE,
+                         req->nb_of_pdusessions,
+                         req->pdusession_param,
+                         /*req->ueAggMaxBitRateDownlink*/ 0);
+  } else {
+    rrc_gNB_generate_SecurityModeCommand(&ctxt, ue_context_p, 0, NULL);
+  }
 
   return 0;
 }
@@ -762,109 +845,9 @@ void rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ(MessageDef *msg_p, instance_t ins
     return ;
   }
 
-  UE->rrc_ue_id = msg->gNB_ue_ngap_id;
+  AssertFatal(UE->rrc_ue_id == msg->gNB_ue_ngap_id, "logic bug\n");
   UE->amf_ue_ngap_id = msg->amf_ue_ngap_id;
-  e1ap_bearer_setup_req_t bearer_req = {0};
-
-
-  e1ap_nssai_t cuup_nssai = {0};
-  for (int i = 0; i < msg->nb_pdusessions_tosetup; i++) {
-    rrc_pdu_session_param_t *pduSession = find_pduSession(UE, msg->pdusession_setup_params[i].pdusession_id, true);
-    pdusession_t *session = &pduSession->param;
-    session->pdusession_id = msg->pdusession_setup_params[i].pdusession_id;
-    LOG_I(NR_RRC, "Adding pdusession %d, total nb of sessions %d\n", session->pdusession_id, UE->nb_of_pdusessions);
-    session->pdu_session_type = msg->pdusession_setup_params[i].pdu_session_type;
-    session->nas_pdu = msg->pdusession_setup_params[i].nas_pdu;
-    session->pdusessionTransfer = msg->pdusession_setup_params[i].pdusessionTransfer;
-    session->nssai = msg->pdusession_setup_params[i].nssai;
-    decodePDUSessionResourceSetup(session);
-    bearer_req.gNB_cu_cp_ue_id = msg->gNB_ue_ngap_id;
-    bearer_req.cipheringAlgorithm = UE->ciphering_algorithm;
-    bearer_req.integrityProtectionAlgorithm = UE->integrity_algorithm;
-    nr_derive_key(UP_ENC_ALG, UE->ciphering_algorithm, UE->kgnb, (uint8_t *)bearer_req.encryptionKey);
-    nr_derive_key(UP_INT_ALG, UE->integrity_algorithm, UE->kgnb, (uint8_t *)bearer_req.integrityProtectionKey);
-    bearer_req.ueDlAggMaxBitRate = msg->ueAggMaxBitRateDownlink;
-    pdu_session_to_setup_t *pdu = bearer_req.pduSession + bearer_req.numPDUSessions;
-    bearer_req.numPDUSessions++;
-    pdu->sessionId = session->pdusession_id;
-    pdu->nssai = msg->pdusession_setup_params[i].nssai;
-    if (cuup_nssai.sst == 0)
-      cuup_nssai = pdu->nssai; /* for CU-UP selection below */
-    pdu->integrityProtectionIndication = rrc->security.do_drb_integrity ? E1AP_IntegrityProtectionIndication_required : E1AP_IntegrityProtectionIndication_not_needed;
-
-    pdu->confidentialityProtectionIndication = rrc->security.do_drb_ciphering ? E1AP_ConfidentialityProtectionIndication_required : E1AP_ConfidentialityProtectionIndication_not_needed;
-    pdu->teId = session->gtp_teid;
-    memcpy(&pdu->tlAddress, session->upf_addr.buffer, 4); // Fixme: dirty IPv4 target
-
-    /* we assume for the moment one DRB per PDU session. Activate the bearer,
-     * and configure in RRC. */
-    int drb_id = get_next_available_drb_id(UE);
-    drb_t *rrc_drb = generateDRB(UE,
-                                 drb_id,
-                                 pduSession,
-                                 rrc->configuration.enable_sdap,
-                                 rrc->security.do_drb_integrity,
-                                 rrc->security.do_drb_ciphering);
-
-    pdu->numDRB2Setup = 1; // One DRB per PDU Session. TODO: Remove hardcoding
-    for (int j=0; j < pdu->numDRB2Setup; j++) {
-      DRB_nGRAN_to_setup_t *drb = pdu->DRBnGRanList + j;
-
-      drb->id = rrc_drb->drb_id;
-
-      struct sdap_config_s *sdap_config = &rrc_drb->cnAssociation.sdap_config;
-      drb->defaultDRB = sdap_config->defaultDRB ? E1AP_DefaultDRB_true : E1AP_DefaultDRB_false;
-      drb->sDAP_Header_UL = sdap_config->sdap_HeaderUL;
-      drb->sDAP_Header_DL = sdap_config->sdap_HeaderDL;
-
-      struct pdcp_config_s *pdcp_config = &rrc_drb->pdcp_config;
-      drb->pDCP_SN_Size_UL = pdcp_config->pdcp_SN_SizeUL;
-      drb->pDCP_SN_Size_DL = pdcp_config->pdcp_SN_SizeDL;
-      drb->discardTimer = pdcp_config->discardTimer;
-      drb->reorderingTimer = pdcp_config->t_Reordering;
-
-      drb->rLC_Mode = rrc->configuration.um_on_default_drb ? E1AP_RLC_Mode_rlc_um_bidirectional : E1AP_RLC_Mode_rlc_am;
-
-      drb->numCellGroups = 1; // assume one cell group associated with a DRB
-
-      for (int k=0; k < drb->numCellGroups; k++) {
-        cell_group_t *cellGroup = drb->cellGroupList + k;
-        cellGroup->id = 0; // MCG
-      }
-
-      drb->numQosFlow2Setup = session->nb_qos;
-      for (int k=0; k < drb->numQosFlow2Setup; k++) {
-        qos_flow_to_setup_t *qos_flow = drb->qosFlows + k;
-        pdusession_level_qos_parameter_t *qos_session = session->qos + k;
-
-        qos_characteristics_t *qos_char = &qos_flow->qos_params.qos_characteristics;
-        qos_flow->qfi = qos_session->qfi;
-        qos_char->qos_type = qos_session->fiveQI_type;
-        if (qos_char->qos_type == dynamic) {
-          qos_char->dynamic.fiveqi = qos_session->fiveQI;
-          qos_char->dynamic.qos_priority_level = qos_session->qos_priority;
-        } else {
-          qos_char->non_dynamic.fiveqi = qos_session->fiveQI;
-          qos_char->non_dynamic.qos_priority_level = qos_session->qos_priority;
-        }
-
-        ngran_allocation_retention_priority_t *rent_priority = &qos_flow->qos_params.alloc_reten_priority;
-        ngap_allocation_retention_priority_t *rent_priority_in = &qos_session->allocation_retention_priority;
-        rent_priority->priority_level = rent_priority_in->priority_level;
-        rent_priority->preemption_capability = rent_priority_in->pre_emp_capability;
-        rent_priority->preemption_vulnerability = rent_priority_in->pre_emp_vulnerability;
-      }
-    }
-  }
-  int xid = rrc_gNB_get_next_transaction_identifier(instance);
-  UE->xids[xid] = RRC_PDUSESSION_ESTABLISH;
-  /* Limitation: we assume one fixed CU-UP per UE. We base the selection on
-   * NSSAI, but the UE might have multiple PDU sessions with differing slices,
-   * in which we might need to select different CU-UPs. In this case, we would
-   * actually need to group the E1 bearer context setup for the different
-   * CU-UPs, and send them to the different CU-UPs. */
-  sctp_assoc_t assoc_id = get_new_cuup_for_ue(rrc, UE, cuup_nssai.sst, cuup_nssai.sd);
-  rrc->cucp_cuup.bearer_context_setup(assoc_id, &bearer_req);
+  trigger_bearer_setup(rrc, UE, msg->nb_pdusessions_tosetup, msg->pdusession_setup_params, msg->ueAggMaxBitRateDownlink);
   return;
 }