diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
index 5b99631d73..977bbc0403 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c
@@ -144,6 +144,12 @@ void f1_setup_failure(const f1ap_setup_failure_t *failure)
   exit(1);
 }
 
+void gnb_du_configuration_update_acknowledge(const f1ap_gnb_du_configuration_update_acknowledge_t *ack)
+{
+  (void)ack;
+  LOG_I(MAC, "received gNB-DU configuration update acknowledge\n");
+}
+
 static NR_RLC_BearerConfig_t *get_bearerconfig_from_srb(const f1ap_srb_to_be_setup_t *srb)
 {
   long priority = srb->srb_id; // high priority for SRB
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.h b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.h
index 799285713e..7a284f2d8b 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.h
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.h
@@ -28,6 +28,7 @@
 
 void f1_setup_response(const f1ap_setup_resp_t *resp);
 void f1_setup_failure(const f1ap_setup_failure_t *failure);
+void gnb_du_configuration_update_acknowledge(const f1ap_gnb_du_configuration_update_acknowledge_t *ack);
 NR_CellGroupConfig_t *clone_CellGroupConfig(const NR_CellGroupConfig_t *orig);
 void ue_context_setup_request(const f1ap_ue_context_setup_t *req);
 void ue_context_modification_request(const f1ap_ue_context_modif_req_t *req);
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul.h b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul.h
index 7519691334..0d902a77c6 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul.h
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul.h
@@ -26,6 +26,7 @@
 #include "f1ap_messages_types.h"
 
 typedef void (*f1_setup_request_func_t)(const f1ap_setup_req_t* req);
+typedef void (*gnb_du_configuration_update_t)(const f1ap_gnb_du_configuration_update_t *upd);
 
 typedef void (*ue_context_setup_response_func_t)(const f1ap_ue_context_setup_t* req, const f1ap_ue_context_setup_t *resp);
 typedef void (*ue_context_modification_response_func_t)(const f1ap_ue_context_modif_req_t *req,
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_direct.c b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_direct.c
index d3320c9ac2..9cb6613d87 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_direct.c
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_direct.c
@@ -66,6 +66,52 @@ static void f1_setup_request_direct(const f1ap_setup_req_t *req)
   itti_send_msg_to_task(TASK_RRC_GNB, 0, msg);
 }
 
+static void gnb_du_configuration_update_direct(const f1ap_gnb_du_configuration_update_t *upd)
+{
+  MessageDef *msg = itti_alloc_new_message(TASK_MAC_GNB, 0, F1AP_GNB_DU_CONFIGURATION_UPDATE);
+  msg->ittiMsgHeader.originInstance = -1; // means monolithic
+  f1ap_gnb_du_configuration_update_t *f1ap_msg = &F1AP_GNB_DU_CONFIGURATION_UPDATE(msg);
+  DevAssert(upd->gNB_DU_ID == NULL);
+  f1ap_msg->transaction_id = upd->transaction_id;
+  DevAssert(upd->num_cells_to_add == 0);
+  DevAssert(upd->num_cells_to_delete == 0);
+
+  f1ap_msg->num_cells_to_modify = upd->num_cells_to_modify;
+  for (int n = 0; n < upd->num_cells_to_modify; ++n) {
+    f1ap_msg->cell_to_modify[n].old_nr_cellid = upd->cell_to_modify[n].old_nr_cellid;
+    f1ap_msg->cell_to_modify[n].info = upd->cell_to_modify[n].info; // copy most fields
+    if (upd->cell_to_modify[n].info.tac) {
+      f1ap_msg->cell_to_modify[n].info.tac = malloc(sizeof(*f1ap_msg->cell_to_modify[n].info.tac));
+      AssertFatal(f1ap_msg->cell_to_modify[n].info.tac != NULL, "out of memory\n");
+      *f1ap_msg->cell_to_modify[n].info.tac = *upd->cell_to_modify[n].info.tac;
+    }
+    if (upd->cell_to_modify[n].info.measurement_timing_information)
+      f1ap_msg->cell_to_modify[n].info.measurement_timing_information =
+          strdup(upd->cell_to_modify[n].info.measurement_timing_information);
+
+    if (upd->cell_to_modify[n].sys_info) {
+      f1ap_gnb_du_system_info_t *orig_sys_info = upd->cell_to_modify[n].sys_info;
+      f1ap_gnb_du_system_info_t *copy_sys_info = calloc(1, sizeof(*copy_sys_info));
+      AssertFatal(copy_sys_info != NULL, "out of memory\n");
+      f1ap_msg->cell_to_modify[n].sys_info = copy_sys_info;
+
+      copy_sys_info->mib = calloc(orig_sys_info->mib_length, sizeof(uint8_t));
+      AssertFatal(copy_sys_info->mib != NULL, "out of memory\n");
+      memcpy(copy_sys_info->mib, orig_sys_info->mib, orig_sys_info->mib_length);
+      copy_sys_info->mib_length = orig_sys_info->mib_length;
+
+      if (orig_sys_info->sib1_length > 0) {
+        copy_sys_info->sib1 = calloc(orig_sys_info->sib1_length, sizeof(uint8_t));
+        AssertFatal(copy_sys_info->sib1 != NULL, "out of memory\n");
+        memcpy(copy_sys_info->sib1, orig_sys_info->sib1, orig_sys_info->sib1_length);
+        copy_sys_info->sib1_length = orig_sys_info->sib1_length;
+      }
+    }
+  }
+
+  itti_send_msg_to_task(TASK_RRC_GNB, 0, msg);
+}
+
 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);
@@ -227,6 +273,7 @@ static void initial_ul_rrc_message_transfer_direct(module_id_t module_id, const
 void mac_rrc_ul_direct_init(struct nr_mac_rrc_ul_if_s *mac_rrc)
 {
   mac_rrc->f1_setup_request = f1_setup_request_direct;
+  mac_rrc->gnb_du_configuration_update = gnb_du_configuration_update_direct;
   mac_rrc->ue_context_setup_response = ue_context_setup_response_direct;
   mac_rrc->ue_context_modification_response = ue_context_modification_response_direct;
   mac_rrc->ue_context_modification_required = ue_context_modification_required_direct;
diff --git a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_f1ap.c b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_f1ap.c
index e4fb8b8f0f..6318934328 100644
--- a/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_f1ap.c
+++ b/openair2/LAYER2/NR_MAC_gNB/mac_rrc_ul_f1ap.c
@@ -98,6 +98,11 @@ static void f1_setup_request_f1ap(const f1ap_setup_req_t *req)
   itti_send_msg_to_task(TASK_DU_F1, 0, msg);
 }
 
+static void gnb_du_configuration_update_f1ap(const f1ap_gnb_du_configuration_update_t *upd)
+{
+  AssertFatal(false, "%s() not implemented\n", __func__);
+}
+
 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);
@@ -237,6 +242,7 @@ static void initial_ul_rrc_message_transfer_f1ap(module_id_t module_id, const f1
 void mac_rrc_ul_f1ap_init(struct nr_mac_rrc_ul_if_s *mac_rrc)
 {
   mac_rrc->f1_setup_request = f1_setup_request_f1ap;
+  mac_rrc->gnb_du_configuration_update = gnb_du_configuration_update_f1ap;
   mac_rrc->ue_context_setup_response = ue_context_setup_response_f1ap;
   mac_rrc->ue_context_modification_response = ue_context_modification_response_f1ap;
   mac_rrc->ue_context_modification_required = ue_context_modification_required_f1ap;
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
index 02b5f54a56..341f972a76 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
@@ -660,6 +660,7 @@ typedef struct NR_bler_options {
 
 typedef struct nr_mac_rrc_ul_if_s {
   f1_setup_request_func_t f1_setup_request;
+  gnb_du_configuration_update_t gnb_du_configuration_update;
   ue_context_setup_response_func_t ue_context_setup_response;
   ue_context_modification_response_func_t ue_context_modification_response;
   ue_context_modification_required_func_t ue_context_modification_required;
diff --git a/openair2/RRC/NR/mac_rrc_dl_direct.c b/openair2/RRC/NR/mac_rrc_dl_direct.c
index 2373b548eb..4b0afbc0e1 100644
--- a/openair2/RRC/NR/mac_rrc_dl_direct.c
+++ b/openair2/RRC/NR/mac_rrc_dl_direct.c
@@ -39,7 +39,7 @@ static void f1_setup_failure_direct(sctp_assoc_t assoc_id, const f1ap_setup_fail
 static void gnb_du_configuration_update_ack_direct(sctp_assoc_t assoc_id, const f1ap_gnb_du_configuration_update_acknowledge_t *ack)
 {
   AssertFatal(assoc_id == -1, "illegal assoc_id %d\n", assoc_id);
-  AssertFatal(false, "%s() not implemented\n", __func__);
+  gnb_du_configuration_update_acknowledge(ack);
 }
 
 static void ue_context_setup_request_direct(sctp_assoc_t assoc_id, const f1ap_ue_context_setup_t *req)