diff --git a/components/net/lwip/src/core/netif.c b/components/net/lwip/src/core/netif.c
index 48c69bcde9783614d5f06852bcf62d5f72d505a1..df6b6faf38fec706171a422615a3f7509fcd97be 100644
--- a/components/net/lwip/src/core/netif.c
+++ b/components/net/lwip/src/core/netif.c
@@ -471,6 +471,9 @@ void netif_set_status_callback(struct netif *netif, void (* status_callback)(str
  */
 void netif_set_link_up(struct netif *netif )
 {
+  /* not notify link up anymore */
+  if (netif->flags & NETIF_FLAG_LINK_UP) return; 
+  
   netif->flags |= NETIF_FLAG_LINK_UP;
 
 #if LWIP_DHCP
diff --git a/components/net/lwip/src/include/lwip/netifapi.h b/components/net/lwip/src/include/lwip/netifapi.h
index 4145dd740ade0c476663a84042852e766b4fe1f1..a9f63651c642f020354ae581170261f09202397a 100644
--- a/components/net/lwip/src/include/lwip/netifapi.h
+++ b/components/net/lwip/src/include/lwip/netifapi.h
@@ -96,6 +96,9 @@ err_t netifapi_netif_common    ( struct netif *netif,
 #define netifapi_autoip_start(n)      netifapi_netif_common(n, NULL, autoip_start)
 #define netifapi_autoip_stop(n)       netifapi_netif_common(n, NULL, autoip_stop)
 
+#define netifapi_netif_set_link_up(n)      netifapi_netif_common(n, netif_set_link_up, NULL)
+#define netifapi_netif_set_link_down(n)    netifapi_netif_common(n, netif_set_link_down, NULL)
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/components/net/lwip/src/include/netif/ethernetif.h b/components/net/lwip/src/include/netif/ethernetif.h
index 2681de560595fd7c3fb5a54403ac53021ce8bb39..87b38497d8698092898c1125751a748f3fe1449a 100644
--- a/components/net/lwip/src/include/netif/ethernetif.h
+++ b/components/net/lwip/src/include/netif/ethernetif.h
@@ -16,12 +16,17 @@ struct eth_device
 	struct netif *netif;
 	struct rt_semaphore tx_ack;
 
+	rt_uint16_t link_changed;
+	rt_uint16_t link_status;
+
 	/* eth device interface */
 	struct pbuf* (*eth_rx)(rt_device_t dev);
 	rt_err_t (*eth_tx)(rt_device_t dev, struct pbuf* p);
 };
 
+rt_err_t eth_rx_ready(struct eth_device* dev);
 rt_err_t eth_device_ready(struct eth_device* dev);
+rt_err_t eth_device_linkchange(struct eth_device* dev, rt_bool_t up);
 
 rt_err_t eth_device_init(struct eth_device* dev, const char* name);
 
diff --git a/components/net/lwip/src/lwipopts.h b/components/net/lwip/src/lwipopts.h
index c02c6650880e0165e2bf04c7b1e7c3788a72d558..a706d386abf5caf236db2f63eb6cbc954756d04d 100644
--- a/components/net/lwip/src/lwipopts.h
+++ b/components/net/lwip/src/lwipopts.h
@@ -178,13 +178,13 @@
 #define TCP_QUEUE_OOSEQ             1
 
 /* TCP Maximum segment size. */
-#define TCP_MSS                     1024
+#define TCP_MSS                     1460
 
 /* TCP sender buffer space (bytes). */
 #ifdef RT_LWIP_TCP_SND_BUF
 #define TCP_SND_BUF                 RT_LWIP_TCP_SND_BUF
 #else
-#define TCP_SND_BUF                 2048
+#define TCP_SND_BUF                 (TCP_MSS * 2)
 #endif
 
 /* TCP sender buffer space (pbufs). This must be at least = 2 *
@@ -198,9 +198,9 @@
 
 /* TCP receive window. */
 #ifdef RT_LWIP_TCP_WND
-#define TCP_WND                 RT_LWIP_TCP_WND
+#define TCP_WND                 	RT_LWIP_TCP_WND
 #else
-#define TCP_WND                 1500
+#define TCP_WND                 	(TCP_MSS * 2)
 #endif
 
 /* Maximum number of retransmissions of data segments. */
diff --git a/components/net/lwip/src/netif/ethernetif.c b/components/net/lwip/src/netif/ethernetif.c
index 0eab86a36e77265502c9cdb4ca46667add922dd3..76660b04e7b80b226eb7a76d669616b17d87acf2 100644
--- a/components/net/lwip/src/netif/ethernetif.c
+++ b/components/net/lwip/src/netif/ethernetif.c
@@ -188,6 +188,23 @@ void eth_rx_thread_entry(void* parameter)
  		{
 			struct pbuf *p;
 
+			/* check link status */
+			if (device->link_changed)
+			{
+				int status;
+				rt_uint32_t level;
+
+				level = rt_hw_interrupt_disable();
+				status = device->link_status;
+				device->link_changed = 0x00;
+				rt_hw_interrupt_enable(level);
+
+				if (status)
+					netifapi_netif_set_link_up(device->netif);
+				else
+					netifapi_netif_set_link_down(device->netif);
+			}
+
 			/* receive all of buffer */
 			while (1)
 			{
@@ -219,6 +236,24 @@ rt_err_t eth_device_ready(struct eth_device* dev)
 	return eth_rx_ready(dev);
 }
 
+rt_err_t eth_device_linkchange(struct eth_device* dev, rt_bool_t up)
+{
+	rt_uint32_t level;
+	
+	RT_ASSERT(dev != RT_NULL);
+
+	level = rt_hw_interrupt_disable();
+	dev->link_changed = 0x01;
+	if (up == RT_TRUE)
+		dev->link_status = 0x01;
+	else
+		dev->link_status = 0x00;
+	rt_hw_interrupt_enable(level);
+
+	/* post message to ethernet thread */
+	return rt_mb_send(&eth_rx_thread_mb, (rt_uint32_t)dev);
+}
+
 rt_err_t eth_system_device_init()
 {
 	rt_err_t result = RT_EOK;