diff --git a/src/mesh/mesh_access.c b/src/mesh/mesh_access.c
index 9343b12bc..77aaf804a 100644
--- a/src/mesh/mesh_access.c
+++ b/src/mesh/mesh_access.c
@@ -119,92 +119,14 @@ uint32_t mesh_access_acknowledged_message_timeout_ms(void){
 #define MESH_ACCESS_OPCODE_INVALID 0xFFFFFFFFu
 #define MESH_ACCESS_OPCODE_NOT_SET 0xFFFFFFFEu
 
-static uint32_t mesh_access_message_ack_opcode(mesh_pdu_t * pdu){
-    switch (pdu->pdu_type){
-        case MESH_PDU_TYPE_TRANSPORT:
-            return ((mesh_transport_pdu_t *)pdu)->ack_opcode;
-        case MESH_PDU_TYPE_SEGMENTED:
-            return ((mesh_segmented_pdu_t *)pdu)->ack_opcode;
-        default:
-            btstack_assert(0);
-            return MESH_ACCESS_OPCODE_INVALID;
-    }
-}
-
-static void mesh_access_message_set_ack_opcode(mesh_pdu_t * pdu, uint32_t ack_opcode){
-    switch (pdu->pdu_type){
-        case MESH_PDU_TYPE_TRANSPORT:
-            ((mesh_transport_pdu_t *)pdu)->ack_opcode = ack_opcode;
-            break;
-        case MESH_PDU_TYPE_SEGMENTED:
-            ((mesh_segmented_pdu_t *)pdu)->ack_opcode = ack_opcode;
-            break;
-        default:
-            btstack_assert(0);
-            break;
-    }
-}
-
-static uint8_t mesh_access_message_retransmit_count(mesh_pdu_t * pdu){
-    switch (pdu->pdu_type){
-        case MESH_PDU_TYPE_TRANSPORT:
-            return ((mesh_transport_pdu_t *)pdu)->retransmit_count;
-        case MESH_PDU_TYPE_SEGMENTED:
-            return ((mesh_segmented_pdu_t *)pdu)->retransmit_count;
-        default:
-            btstack_assert(0);
-            return 0;
-    }
-}
-
-static void mesh_access_message_set_retransmit_count(mesh_pdu_t * pdu, uint8_t retransmit_count){
-    switch (pdu->pdu_type){
-        case MESH_PDU_TYPE_TRANSPORT:
-            ((mesh_transport_pdu_t *)pdu)->retransmit_count = retransmit_count;
-            break;
-        case MESH_PDU_TYPE_SEGMENTED:
-            ((mesh_segmented_pdu_t *)pdu)->retransmit_count = retransmit_count;
-            break;
-        default:
-            btstack_assert(0);
-            break;
-    }
-}
-
-static uint32_t mesh_access_message_retransmit_timeout_ms(mesh_pdu_t * pdu){
-    switch (pdu->pdu_type){
-        case MESH_PDU_TYPE_TRANSPORT:
-            return ((mesh_transport_pdu_t *)pdu)->retransmit_timeout_ms;
-        case MESH_PDU_TYPE_SEGMENTED:
-            return ((mesh_segmented_pdu_t *)pdu)->retransmit_timeout_ms;
-        default:
-            btstack_assert(0);
-            return 0;
-    }
-}
-
-static void mesh_access_message_set_retransmit_timeout_ms(mesh_pdu_t * pdu, uint32_t retransmit_timeout_ms){
-    switch (pdu->pdu_type){
-        case MESH_PDU_TYPE_TRANSPORT:
-            ((mesh_transport_pdu_t *)pdu)->retransmit_timeout_ms = retransmit_timeout_ms;
-            break;
-        case MESH_PDU_TYPE_SEGMENTED:
-            ((mesh_segmented_pdu_t *)pdu)->retransmit_timeout_ms = retransmit_timeout_ms;
-            break;
-        default:
-            btstack_assert(0);
-            break;
-    }
-}
-
 void mesh_access_send_unacknowledged_pdu(mesh_pdu_t * pdu){
-    mesh_access_message_set_ack_opcode(pdu, MESH_ACCESS_OPCODE_INVALID);
+    ((mesh_upper_transport_pdu_t *) pdu)->ack_opcode = MESH_ACCESS_OPCODE_INVALID;
     mesh_upper_transport_send_access_pdu(pdu);
 }
 
 void mesh_access_send_acknowledged_pdu(mesh_pdu_t * pdu, uint8_t retransmissions, uint32_t ack_opcode){
-    mesh_access_message_set_retransmit_count(pdu, retransmissions);
-    mesh_access_message_set_ack_opcode(pdu, ack_opcode);
+    ((mesh_upper_transport_pdu_t *) pdu)->retransmit_count = retransmissions;
+    ((mesh_upper_transport_pdu_t *) pdu)->ack_opcode = ack_opcode;
 
     mesh_upper_transport_send_access_pdu(pdu);
 }
@@ -221,14 +143,14 @@ static void mesh_access_acknowledged_run(btstack_timer_source_t * ts){
     btstack_linked_list_iterator_init(&ack_it, &mesh_access_acknowledged_messages);
     while (btstack_linked_list_iterator_has_next(&ack_it)){
         mesh_pdu_t * pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&ack_it);
-        uint32_t retransmit_timeout_ms = mesh_access_message_retransmit_timeout_ms(pdu);
+        uint32_t retransmit_timeout_ms = ((mesh_upper_transport_pdu_t *) pdu)->retransmit_timeout_ms;
         if (btstack_time_delta(now, retransmit_timeout_ms) >= 0) {
             // remove from list
             btstack_linked_list_remove(&mesh_access_acknowledged_messages, (btstack_linked_item_t*) pdu);
             // retransmit or report failure
-            uint8_t retransmit_count = mesh_access_message_retransmit_count(pdu);
+            uint8_t retransmit_count = ((mesh_upper_transport_pdu_t *) pdu)->retransmit_count;
             if (retransmit_count){
-                mesh_access_message_set_retransmit_count(pdu, retransmit_count - 1);
+                ((mesh_upper_transport_pdu_t *) pdu)->retransmit_count = retransmit_count - 1;
                 mesh_upper_transport_send_access_pdu(pdu);
             } else {
                 // find correct model and emit error
@@ -242,7 +164,7 @@ static void mesh_access_acknowledged_run(btstack_timer_source_t * ts){
                     while (mesh_model_iterator_has_next(&model_it)){
                         mesh_model_t * model = mesh_model_iterator_next(&model_it);
                         // find opcode in table
-                        uint32_t ack_opcode = mesh_access_message_ack_opcode(pdu);
+                        uint32_t ack_opcode = ((mesh_upper_transport_pdu_t *) pdu)->ack_opcode;
                         const mesh_operation_t * operation = mesh_model_lookup_operation_by_opcode(model, ack_opcode);
                         if (operation == NULL) continue;
                         if (model->model_packet_handler == NULL) continue;
@@ -271,7 +193,7 @@ static void mesh_access_acknowledged_run(btstack_timer_source_t * ts){
     int32_t next_timeout_ms = 0;
     while (btstack_linked_list_iterator_has_next(&ack_it)){
         mesh_pdu_t * pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&ack_it);
-        uint32_t retransmit_timeout_ms = mesh_access_message_retransmit_timeout_ms(pdu);
+        uint32_t retransmit_timeout_ms = ((mesh_upper_transport_pdu_t *) pdu)->retransmit_timeout_ms;
         int32_t timeout_delta_ms = btstack_time_delta(retransmit_timeout_ms, now);
         if (next_timeout_ms == 0 || timeout_delta_ms < next_timeout_ms){
             next_timeout_ms = timeout_delta_ms;
@@ -297,7 +219,7 @@ static void mesh_access_acknowledged_received(uint16_t rx_src, uint32_t opcode){
         mesh_pdu_t * tx_pdu = (mesh_pdu_t *) btstack_linked_list_iterator_next(&ack_it);
         uint16_t tx_dest = mesh_pdu_dst(tx_pdu);
         if (tx_dest != rx_src) continue;
-        if (mesh_access_message_ack_opcode(tx_pdu) != opcode) continue;
+        if (((mesh_upper_transport_pdu_t *) tx_pdu)->ack_opcode != opcode) continue;
         // got expected response from dest, remove from outgoing messages
         mesh_upper_transport_pdu_free(tx_pdu);
         return;
@@ -312,12 +234,16 @@ static void mesh_access_upper_transport_handler(mesh_transport_callback_type_t c
             break;
         case MESH_TRANSPORT_PDU_SENT:
             // unacknowledged -> free
-            if (mesh_access_message_ack_opcode(pdu) == MESH_ACCESS_OPCODE_INVALID){
+        {
+            if (((mesh_upper_transport_pdu_t *) pdu)->ack_opcode == MESH_ACCESS_OPCODE_INVALID){
                 mesh_upper_transport_pdu_free(pdu);
                 break;
             }
+        }
             // setup timeout
-            mesh_access_message_set_retransmit_timeout_ms(pdu, btstack_run_loop_get_time_ms() + mesh_access_acknowledged_message_timeout_ms());
+            uint32_t retransmitTimeoutMs =
+                    btstack_run_loop_get_time_ms() + mesh_access_acknowledged_message_timeout_ms();
+            ((mesh_upper_transport_pdu_t *) pdu)->retransmit_timeout_ms = retransmitTimeoutMs;
             // add to mesh_access_acknowledged_messages
             btstack_linked_list_add(&mesh_access_acknowledged_messages, (btstack_linked_item_t *) pdu);
             // update timer