diff --git a/APP/peripheral.c b/APP/peripheral.c
index 7937cc5..3e85afd 100644
--- a/APP/peripheral.c
+++ b/APP/peripheral.c
@@ -380,6 +380,7 @@ uint16_t Peripheral_ProcessEvent(uint8_t task_id, uint16_t events)
         // Restart timer
         if(periodic_upload_block_flag == false && mtu_flag == 1)
         {
+            logWarning("SBP_PERIODIC_EVT");
             performPeriodicTask();
             tmos_start_task(Peripheral_TaskID, SBP_PERIODIC_EVT, SBP_PERIODIC_EVT_PERIOD);
         }
@@ -491,7 +492,8 @@ static void Peripheral_ProcessTMOSMsg(tmos_event_hdr_t *pMsg)
             {
                 peripheralMTU = pMsgEvent->msg.exchangeMTUReq.clientRxMTU;
                 mtu_flag = 1;
-                logDebug("****mtu exchange: %d****", pMsgEvent->msg.exchangeMTUReq.clientRxMTU);
+                logWarning("****mtu exchange: %d****", pMsgEvent->msg.exchangeMTUReq.clientRxMTU);
+                performPeriodicTask();
             }
             break;
         }
diff --git a/HAL/include/CONFIG.h b/HAL/include/CONFIG.h
index 02bce9f..2394d71 100644
--- a/HAL/include/CONFIG.h
+++ b/HAL/include/CONFIG.h
@@ -126,7 +126,7 @@
 #define BLE_MEMHEAP_SIZE                    (1024*6)
 #endif
 #ifndef BLE_BUFF_MAX_LEN
-#define BLE_BUFF_MAX_LEN                    27
+#define BLE_BUFF_MAX_LEN                    251 // MTU  https://www.cnblogs.com/gscw/p/17896209.html
 #endif
 #ifndef BLE_BUFF_NUM
 #define BLE_BUFF_NUM                        5
diff --git a/bsp/src/bsp_ml307r.c b/bsp/src/bsp_ml307r.c
index 413e6f7..e046c55 100644
--- a/bsp/src/bsp_ml307r.c
+++ b/bsp/src/bsp_ml307r.c
@@ -521,7 +521,7 @@ static int BSP_Module_Connect_CtWing_Handle(at_env_t *e)
     {
         case 0:
             logDebug("create device...\r\n");  
-            e->println(e, "AT+MIPOPEN=0,\"TCP\",\"112.125.89.8\",42286,,1");  // 8.135.10.183,32994
+            e->println(e, "AT+MIPOPEN=0,\"TCP\",\"112.125.89.8\",42519,,1");  // 8.135.10.183,32994
             e->reset_timer(e);
             e->state++;
             break;