This paper proposes a zero-copy packet loss recovery mechanism on light weight TCP/IP stack. Meanwhile, a new Persistent Timer especially for multimedia streaming is also described. With these two mechanisms, the multimedia streaming transmission could work more effectively and stably on embedded system, avoiding the network congestion. Besides that, an efficiency and stability test is proposed for this improved light weight TCP stack under various transmission situations. Experimental results show that the optimizated light weight TCP/IP stack could keep working under different network congestion.