Introduce separate gNB-CU-UP ID in configuration

3GPP has the concept of a gNB-CU-UP ID and a (separate) gNB ID (for gNB,
CU-CP). This commit introduces the gNB-CU-UP as a separate ID that has to be
set in the configuration file when running as a CU-UP. For the
CU/monolithic gNB, it is optional (but needs to be the same as the
gNB-ID if specified).

The CU-UP ID is necessary, as some entities, e.g., the e2 agent, need to
signal both IDs, e.g., to reconcile a CU-CP and (multiple) CU-UP(s)
belonging together.

ci-scripts/conf_files/gnb-cuup.sa.f1.conf

@@ -8,6 +8,7 @@ gNBs =
  {
     ////////// Identification parameters:
     gNB_ID = 0xe00;
+    gNB_CU_UP_ID = 0xe00;
 
 #     cell_type =  "CELL_MACRO_GNB";
 

ci-scripts/conf_files/gnb-cuup.sa.f1.quectel.conf

@@ -8,6 +8,7 @@ gNBs =
  {
     ////////// Identification parameters:
     gNB_ID = 0xe00;
+    gNB_CU_UP_ID = 0xe00;
 
 #     cell_type =  "CELL_MACRO_GNB";
 

executables/nr-cuup.c

@@ -130,7 +130,8 @@ int main(int argc, char **argv)
   AssertFatal(rc >= 0, "Create task for CUUP E1 failed\n");
   nr_pdcp_layer_init(true);
   cu_init_f1_ue_data(); // for CU-UP/CP mapping: we use the same
-  MessageDef *msg = RCconfig_NR_CU_E1(true);
+  E1_t e1type = UPtype;
+  MessageDef *msg = RCconfig_NR_CU_E1(&e1type);
   AssertFatal(msg != NULL, "Send init to task for E1AP UP failed\n");
   itti_send_msg_to_task(TASK_CUUP_E1, 0, msg);
 

executables/nr-softmodem.c

@@ -402,9 +402,9 @@ static int create_gNB_tasks(ngran_node_t node_type, configmodule_interface_t *cf
 
     // If CU
     if (node_type == ngran_gNB_CU || node_type == ngran_gNB) {
-      MessageDef *msg = RCconfig_NR_CU_E1(false);
+      MessageDef *msg = RCconfig_NR_CU_E1(NULL);
       instance_t inst = 0;
-      createE1inst(UPtype, inst, &E1AP_REGISTER_REQ(msg).net_config, NULL);
+      createE1inst(UPtype, inst, E1AP_REGISTER_REQ(msg).gnb_id, &E1AP_REGISTER_REQ(msg).net_config, NULL);
       cuup_init_n3(inst);
       RC.nrrrc[gnb_id_start]->e1_inst = inst; // stupid instance !!!*/
 

openair2/COMMON/e1ap_messages_types.h

@@ -87,6 +87,7 @@ typedef struct e1ap_setup_req_s {
 typedef struct e1ap_register_req_t {
   e1ap_setup_req_t setup_req;
   e1ap_net_config_t net_config;
+  uint32_t gnb_id; // unused in CU-UP, but might be necessary for some functionality, e.g., E2 agent
 } e1ap_register_req_t;
 
 typedef struct e1ap_setup_resp_s {

openair2/E1AP/e1ap.c

@@ -1801,7 +1801,7 @@ void cucp_task_send_sctp_init_req(instance_t instance, char *my_addr) {
 void e1_task_handle_sctp_association_ind(E1_t type, instance_t instance, sctp_new_association_ind_t *sctp_new_ind)
 {
   if (!getCxtE1(instance))
-    createE1inst(type, instance, NULL, NULL);
+    createE1inst(type, instance, 0, NULL, NULL);
   e1ap_upcp_inst_t *inst = getCxtE1(instance);
   inst->sockState = SCTP_STATE_ESTABLISHED;
   if (type == UPtype)
@@ -1897,7 +1897,7 @@ void *E1AP_CUUP_task(void *arg) {
     switch (msgType) {
       case E1AP_REGISTER_REQ: {
         e1ap_register_req_t *reg_req = &E1AP_REGISTER_REQ(msg);
-        createE1inst(UPtype, myInstance, &reg_req->net_config, &reg_req->setup_req);
+        createE1inst(UPtype, myInstance, reg_req->gnb_id, &reg_req->net_config, &reg_req->setup_req);
         e1_task_send_sctp_association_req(TASK_CUUP_E1, myInstance, &reg_req->net_config);
       } break;
 

openair2/E1AP/e1ap_common.c

@@ -37,12 +37,13 @@ e1ap_upcp_inst_t *getCxtE1(instance_t instance)
   return e1ap_inst[instance];
 }
 
-void createE1inst(E1_t type, instance_t instance, e1ap_net_config_t *nc, e1ap_setup_req_t *req)
+void createE1inst(E1_t type, instance_t instance, uint64_t gnb_id, e1ap_net_config_t *nc, e1ap_setup_req_t *req)
 {
   AssertFatal(e1ap_inst[instance] == NULL, "Double call to E1 instance %d\n", (int)instance);
   e1ap_inst[instance] = calloc(1, sizeof(e1ap_upcp_inst_t));
   e1ap_inst[instance]->type = type;
   e1ap_inst[instance]->instance = instance;
+  e1ap_inst[instance]->gnb_id = gnb_id;
   e1ap_inst[instance]->cuup.assoc_id = -1;
   if (nc)
     memcpy(&e1ap_inst[instance]->net_config, nc, sizeof(*nc));

openair2/E1AP/e1ap_common.h

@@ -29,6 +29,7 @@
 
 typedef struct e1ap_upcp_inst_s {
   instance_t instance;
+  uint32_t gnb_id; // associated gNB's ID, unused in E1 but necessary for e.g. E2 agent
   E1_t type;
   enum sctp_state_e sockState;
   struct {
@@ -52,7 +53,7 @@ e1ap_upcp_inst_t *getCxtE1(instance_t instance);
 long E1AP_get_next_transaction_identifier();
 void E1AP_free_transaction_identifier(long id);
 
-void createE1inst(E1_t type, instance_t instance, e1ap_net_config_t *nc, e1ap_setup_req_t *req);
+void createE1inst(E1_t type, instance_t instance, uint64_t gnb_id, e1ap_net_config_t *nc, e1ap_setup_req_t *req);
 
 int e1ap_encode_send(E1_t type, sctp_assoc_t assoc_id, struct E1AP_E1AP_PDU *pdu, uint16_t stream, const char *func);
 

openair2/E1AP/e1ap_setup.c

@@ -68,7 +68,7 @@ static void get_NGU_S1U_addr(char **addr, uint16_t *port)
   return;
 }
 
-MessageDef *RCconfig_NR_CU_E1(bool separate_CUUP_process)
+MessageDef *RCconfig_NR_CU_E1(const E1_t *entity)
 {
   MessageDef *msgConfig = itti_alloc_new_message(TASK_GNB_APP, 0, E1AP_REGISTER_REQ);
   if (!msgConfig)
@@ -82,14 +82,12 @@ MessageDef *RCconfig_NR_CU_E1(bool separate_CUUP_process)
   sprintf(aprefix, "%s.[%i]", GNB_CONFIG_STRING_GNB_LIST, 0);
   int num_gnbs = GNBSParams[GNB_ACTIVE_GNBS_IDX].numelt;
   AssertFatal(num_gnbs == 1, "Support only one gNB per process\n");
+  config_getlist(config_get_if(), &GNBParamList, GNBParams, sizeofArray(GNBParams), NULL);
+  paramdef_t *gnbParms = GNBParamList.paramarray[0];
+  e1ap_setup_req_t *e1Setup = &E1AP_REGISTER_REQ(msgConfig).setup_req;
 
   if (num_gnbs > 0) {
-    config_getlist(config_get_if(), &GNBParamList, GNBParams, sizeofArray(GNBParams), NULL);
-    paramdef_t *gnbParms = GNBParamList.paramarray[0];
-    AssertFatal(gnbParms[GNB_GNB_ID_IDX].uptr != NULL, "gNB id %d is not defined in configuration file\n", 0);
-    e1ap_setup_req_t *e1Setup = &E1AP_REGISTER_REQ(msgConfig).setup_req;
     msgConfig->ittiMsgHeader.destinationInstance = 0;
-    e1Setup->gNB_cu_up_id = *(gnbParms[GNB_GNB_ID_IDX].uptr);
     if (*gnbParms[GNB_GNB_NAME_IDX].strptr)
       e1Setup->gNB_cu_up_name = *(gnbParms[GNB_GNB_NAME_IDX].strptr);
 
@@ -132,7 +130,11 @@ MessageDef *RCconfig_NR_CU_E1(bool separate_CUUP_process)
     get_NGU_S1U_addr(&e1ap_nc->localAddressN3, &e1ap_nc->localPortN3);
     e1ap_nc->remotePortN3 = e1ap_nc->localPortN3 ;
 
-    if (separate_CUUP_process) {
+    AssertFatal(config_isparamset(gnbParms, GNB_GNB_ID_IDX), "%s is not defined in configuration file\n", GNB_CONFIG_STRING_GNB_ID);
+    uint32_t gnb_id = *gnbParms[GNB_GNB_ID_IDX].uptr;
+    E1AP_REGISTER_REQ(msgConfig).gnb_id = gnb_id;
+
+    if (entity != NULL) {
       paramlist_def_t GNBE1ParamList = {GNB_CONFIG_STRING_E1_PARAMETERS, NULL, 0};
       paramdef_t GNBE1Params[] = GNBE1PARAMS_DESC;
       config_getlist(config_get_if(), &GNBE1ParamList, GNBE1Params, sizeofArray(GNBE1Params), aprefix);
@@ -141,6 +143,24 @@ MessageDef *RCconfig_NR_CU_E1(bool separate_CUUP_process)
       e1ap_nc->CUCP_e1_ip_address.ipv4 = 1;
       strcpy(e1ap_nc->CUUP_e1_ip_address.ipv4_address, *(e1Parms[GNB_CONFIG_E1_IPV4_ADDRESS_CUUP].strptr));
       e1ap_nc->CUUP_e1_ip_address.ipv4 = 1;
+      if (*entity == CPtype) {
+        // CP needs gNB_ID (although not used, but other parts check it as
+        // well), and gNB-CU-UP ID should NOT be present as it comes through E1!
+        AssertFatal(!config_isparamset(gnbParms, GNB_GNB_CU_UP_ID_IDX), "%s must not be defined in configuration file\n", GNB_CONFIG_STRING_GNB_CU_UP_ID);
+      } else { // UPtype
+        AssertFatal(config_isparamset(gnbParms, GNB_GNB_CU_UP_ID_IDX), "%s is not be defined in configuration file\n", GNB_CONFIG_STRING_GNB_CU_UP_ID);
+        e1Setup->gNB_cu_up_id = *gnbParms[GNB_GNB_CU_UP_ID_IDX].u64ptr;
+      }
+    } else {
+      // integrated CU-CP/UP. We don't care about the gNB-CU-UP ID that much,
+      // but if it's there, check it's the same as gNB ID
+      uint64_t *gnb_cu_up_id = gnbParms[GNB_GNB_CU_UP_ID_IDX].u64ptr;
+      AssertFatal(!config_isparamset(gnbParms, GNB_GNB_CU_UP_ID_IDX) || *gnb_cu_up_id == gnb_id,
+                  "%s is different of %s: they need to match or remove %s from config\n",
+                  GNB_CONFIG_STRING_GNB_CU_UP_ID,
+                  GNB_CONFIG_STRING_GNB_ID,
+                  GNB_CONFIG_STRING_GNB_CU_UP_ID);
+      e1Setup->gNB_cu_up_id = gnb_id;
     }
   }
   return msgConfig;

openair2/GNB_APP/gnb_app.c

@@ -146,7 +146,8 @@ void *gNB_app_task(void *args_p)
     if (node_type == ngran_gNB_CUCP) {
       if (itti_create_task(TASK_CUCP_E1, E1AP_CUCP_task, NULL) < 0)
         AssertFatal(false, "Create task for E1AP CP failed\n");
-      MessageDef *msg = RCconfig_NR_CU_E1(true);
+      E1_t e1type = CPtype;
+      MessageDef *msg = RCconfig_NR_CU_E1(&e1type);
       AssertFatal(msg != NULL, "Send inti to task for E1AP CP failed\n");
       // this sends the E1AP_REGISTER_REQ to CU-CP so it sets up the socket
       // it does NOT use the E1AP part

openair2/GNB_APP/gnb_config.h

@@ -107,7 +107,7 @@ int RCconfig_NR_NG(MessageDef *msg_p, uint32_t i);
 int RCconfig_NR_X2(MessageDef *msg_p, uint32_t i);
 void wait_f1_setup_response(void);
 int gNB_app_handle_f1ap_gnb_cu_configuration_update(f1ap_gnb_cu_configuration_update_t *gnb_cu_cfg_update);
-MessageDef *RCconfig_NR_CU_E1(bool separate_CUUP_process);
+MessageDef *RCconfig_NR_CU_E1(const E1_t *entity);
 ngran_node_t get_node_type(void);
 
 #ifdef E2_AGENT

openair2/GNB_APP/gnb_paramdef.h

@@ -129,11 +129,13 @@ typedef enum {
 #define GNB_CONFIG_STRING_ENABLE_SDAP                   "enable_sdap"
 #define GNB_CONFIG_STRING_DRBS                          "drbs"
 #define GNB_CONFIG_STRING_GNB_DU_ID "gNB_DU_ID"
+#define GNB_CONFIG_STRING_GNB_CU_UP_ID "gNB_CU_UP_ID"
 
 #define GNB_CONFIG_HLP_STRING_ENABLE_SDAP               "enable the SDAP layer\n"
 #define GNB_CONFIG_HLP_FORCE256QAMOFF                   "suppress activation of 256 QAM despite UE support"
 #define GNB_CONFIG_HLP_STRING_DRBS                      "Number of total DRBs to establish, including the mandatory for PDU SEssion (default=1)\n"
 #define GNB_CONFIG_HLP_GNB_DU_ID "defines the gNB-DU ID (only applicable for DU)"
+#define GNB_CONFIG_HLP_GNB_CU_UP_ID "defines the gNB-CU-UP ID (only applicable for CU-UP)"
 
 /*-----------------------------------------------------------------------------------------------------------------------------------------*/
 /*                                            cell configuration parameters                                                                */
@@ -170,6 +172,7 @@ typedef enum {
 {GNB_CONFIG_STRING_ENABLE_SDAP, GNB_CONFIG_HLP_STRING_ENABLE_SDAP, PARAMFLAG_BOOL,.iptr=NULL, .defintval=0,       TYPE_INT,       0},  \
 {GNB_CONFIG_STRING_DRBS, GNB_CONFIG_HLP_STRING_DRBS,     0,            .iptr=NULL,  .defintval=1,                 TYPE_INT,       0},  \
 {GNB_CONFIG_STRING_GNB_DU_ID, GNB_CONFIG_HLP_GNB_DU_ID,   0,          .u64ptr=NULL, .defint64val=1,               TYPE_UINT64,    0},  \
+{GNB_CONFIG_STRING_GNB_CU_UP_ID, GNB_CONFIG_HLP_GNB_CU_UP_ID, 0,      .u64ptr=NULL, .defint64val=1,               TYPE_UINT64,    0},  \
 }
 // clang-format on
 
@@ -203,6 +206,7 @@ typedef enum {
 #define GNB_ENABLE_SDAP_IDX             26
 #define GNB_DRBS                        27
 #define GNB_GNB_DU_ID_IDX 28
+#define GNB_GNB_CU_UP_ID_IDX 29
 
 #define TRACKING_AREA_CODE_OKRANGE {0x0001,0xFFFD}
 #define GNBPARAMS_CHECK {                                         \