diff --git a/bsp/lpc176x/rtconfig.h b/bsp/lpc176x/rtconfig.h
index 31b2b1afee77d709ee05f508371cbe1961ba3a61..61b2f82711475acb8f2d55ae6c9e4921338caf9b 100644
--- a/bsp/lpc176x/rtconfig.h
+++ b/bsp/lpc176x/rtconfig.h
@@ -142,7 +142,7 @@
 // <integer name="RT_LWIP_TCP_PCB_NUM" description="Maximal number of simultaneously active TCP connections" default="5" />
 #define RT_LWIP_TCP_PCB_NUM	3
 // <integer name="RT_LWIP_TCP_SND_BUF" description="TCP sender buffer size" default="8192" />
-#define RT_LWIP_TCP_SND_BUF	2048
+#define RT_LWIP_TCP_SND_BUF	(2 * TCP_MSS)
 // <integer name="RT_LWIP_TCP_WND" description="TCP receive window" default="8192" />
 #define RT_LWIP_TCP_WND	2048
 // <bool name="RT_LWIP_SNMP" description="Enable SNMP protocol" default="false" />
diff --git a/components/net/lwip-1.4.1/src/arch/sys_arch.c b/components/net/lwip-1.4.1/src/arch/sys_arch.c
index fc3b9b84479d77799dfb8819e0fd57b476158d0e..958803f1563a3a5acb9f6635fc16d7a0ec0d5523 100644
--- a/components/net/lwip-1.4.1/src/arch/sys_arch.c
+++ b/components/net/lwip-1.4.1/src/arch/sys_arch.c
@@ -139,7 +139,7 @@ int lwip_system_init(void)
     {
         LWIP_ASSERT("Failed to create semaphore", 0);
 
-        return;
+        return -1;
     }
 
     tcpip_init(tcpip_init_done_callback, (void *)&done_sem);
@@ -149,7 +149,7 @@ int lwip_system_init(void)
     {
         rt_sem_detach(&done_sem);
 
-        return;
+        return -1;
     }
     rt_sem_detach(&done_sem);
 
diff --git a/components/net/lwip-1.4.1/src/include/netif/ethernetif.h b/components/net/lwip-1.4.1/src/include/netif/ethernetif.h
index 4aa4525ce2561b2f383ce8c83ff226c287991a2e..53dacf2270b33721ea36a8b06343b5ed9bb3da68 100644
--- a/components/net/lwip-1.4.1/src/include/netif/ethernetif.h
+++ b/components/net/lwip-1.4.1/src/include/netif/ethernetif.h
@@ -30,6 +30,6 @@ rt_err_t eth_device_init(struct eth_device * dev, char *name);
 rt_err_t eth_device_init_with_flag(struct eth_device *dev, char *name, rt_uint8_t flag);
 rt_err_t eth_device_linkchange(struct eth_device* dev, rt_bool_t up);
 
-void eth_system_device_init(void);
+int eth_system_device_init(void);
 
 #endif /* __NETIF_ETHERNETIF_H__ */
diff --git a/components/net/lwip-1.4.1/src/netif/ethernetif.c b/components/net/lwip-1.4.1/src/netif/ethernetif.c
index 4757981fa05678bda05b9baa053daccc173a6e0b..2853fdcd7c538bb9d6a13bbf624cf0b25eca45e0 100644
--- a/components/net/lwip-1.4.1/src/netif/ethernetif.c
+++ b/components/net/lwip-1.4.1/src/netif/ethernetif.c
@@ -350,7 +350,7 @@ static void eth_rx_thread_entry(void* parameter)
     }
 }
 
-void eth_system_device_init()
+int eth_system_device_init(void)
 {
     rt_err_t result = RT_EOK;
 
@@ -382,6 +382,8 @@ void eth_system_device_init()
 
     result = rt_thread_startup(&eth_tx_thread);
     RT_ASSERT(result == RT_EOK);
+	
+	return 0;
 }
 INIT_DEVICE_EXPORT(eth_system_device_init);