diff --git a/test/mesh/mesh_message_test.c b/test/mesh/mesh_message_test.c
index 1488fa9da..ce71f3161 100644
--- a/test/mesh/mesh_message_test.c
+++ b/test/mesh/mesh_message_test.c
@@ -16,6 +16,18 @@ void adv_bearer_register_for_mesh_message(btstack_packet_handler_t packet_handle
 void adv_bearer_request_can_send_now_for_mesh_message(void){}
 void adv_bearer_send_mesh_message(const uint8_t * network_pdu, uint16_t size){}
 
+void CHECK_EQUAL_ARRAY(uint8_t * expected, uint8_t * actual, int size){
+    int i;
+    for (i=0; i<size; i++){
+        if (expected[i] != actual[i]) {
+            printf("offset %u wrong\n", i);
+            printf("expected: "); printf_hexdump(expected, size);
+            printf("actual:   "); printf_hexdump(actual, size);
+        }
+        BYTES_EQUAL(expected[i], actual[i]);
+    }
+}
+
 static int scan_hex_byte(const char * byte_string){
     int upper_nibble = nibble_for_char(*byte_string++);
     if (upper_nibble < 0) return -1;
@@ -62,7 +74,7 @@ static void load_provisioning_data_test_message(void){
     btstack_parse_hex("0953fa93e7caac9638f58820220a398e", 16, provisioning_data.encryption_key);
     btstack_parse_hex("8b84eedec100067d670971dd2aa700cf", 16, provisioning_data.privacy_key);
     mesh_network_key_list_add_from_provisioning_data(&provisioning_data);
-#if 0
+
     uint8_t application_key[16];
     btstack_parse_hex("63964771734fbd76e3b40519d1d94a48", 16, application_key);
     mesh_application_key_set( 0, 0x26, application_key);
@@ -70,14 +82,11 @@ static void load_provisioning_data_test_message(void){
     uint8_t device_key[16];
     btstack_parse_hex("9d6dd0e96eb25dc19a40ed9914f8f03f", 16, device_key);
     mesh_transport_set_device_key(device_key);
-#endif
 }
 
 static mesh_network_pdu_t * received_network_pdu;
 
-#if 0
-static void mesh_lower_transport_received_mesage(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu){
-    printf("mesh_lower_transport_received_mesage, type %u\n", callback_type);
+static void test_lower_transport_callback_handler(mesh_network_callback_type_t callback_type, mesh_network_pdu_t * network_pdu){
     switch (callback_type){
         case MESH_NETWORK_PDU_RECEIVED:
             received_network_pdu = network_pdu; 
@@ -88,7 +97,6 @@ static void mesh_lower_transport_received_mesage(mesh_network_callback_type_t ca
             break;
     }
 }
-#endif
 
 TEST_GROUP(MessageTest){
     void setup(void){
@@ -96,28 +104,43 @@ TEST_GROUP(MessageTest){
         btstack_crypto_init();
         load_provisioning_data_test_message();
         mesh_network_init();
-        mesh_network_set_higher_layer_handler(&mesh_lower_transport_received_mesage);
+        mesh_network_set_higher_layer_handler(&test_lower_transport_callback_handler);
         received_network_pdu = NULL;
     }
 };
 
-static uint8_t transport_pdu_data[32];
+static uint8_t transport_pdu_data[64];
 static uint16_t transport_pdu_len;
+static const char * transport_pdu_string;
+
 static     uint8_t test_network_pdu_len;
 static uint8_t test_network_pdu_data[29];
-static  const char * test_network_pdu_string;
+static const char * test_network_pdu_string;
 
 TEST(MessageTest, Test1){
-    uint8_t test_network_pdu_data[29];
+
+    // Network PDU 1
     test_network_pdu_string = "68eca487516765b5e5bfdacbaf6cb7fb6bff871f035444ce83a670df";
     test_network_pdu_len = strlen(test_network_pdu_string) / 2;
     btstack_parse_hex(test_network_pdu_string, test_network_pdu_len, test_network_pdu_data);
+
     mesh_network_received_message(test_network_pdu_data, test_network_pdu_len);
+
+    // Expected Lower Transport PDU
+    transport_pdu_string = "034b50057e400000010000";
+    transport_pdu_len = strlen(transport_pdu_string) / 2;
+    btstack_parse_hex(transport_pdu_string, transport_pdu_len, transport_pdu_data);
+
     //
     while (received_network_pdu == NULL) {
         mock_process_hci_cmd();
     }
-    // TODO: check
+
+    uint8_t * lower_transport_pdu     = mesh_network_pdu_data(received_network_pdu);
+    uint8_t   lower_transport_pdu_len = mesh_network_pdu_len(received_network_pdu);
+
+    CHECK_EQUAL( transport_pdu_len, lower_transport_pdu_len);
+    CHECK_EQUAL_ARRAY(transport_pdu_data, lower_transport_pdu, transport_pdu_len);
 }
 
 TEST(MessageTest, Test2){