Research And Implementation Of Structure Optimize Of Embedded TCP/IP Statck

With the rapid development of information networks, equipment net-based are becoming more and moreimportant. Embedded device can remotes control and resource sharing through Internet easily. In addition, with the increase in the amount of information, the embedded device network response time is becaming more and more harsh for the user's requirement. But, the original 8 bit or 16 bit processor has been difficult to make a breakthrough in this regard, and the standard TCP/IP protocol stack for embedded devices seems to be bloated. Therefore, the optimization of network protocol stack and improving network speeds to adapt to the gradual popularity of 32 bit processors become more and more important.This paper analyzes the key parts of implementation of the protocol stack based on the standard TCP/IP protocol stack. Through the analysis of source codes of protocol stack in the Linux kernel, understanding the relationship of internal protocol layers and the relations of the functions drivening from the bottom layer to the application layer of protocol stack, understanding the theory of the protocol stack works widely and proposing a protocol stack of the optimize program as following:As the result of complicated funcations implementation of the standard TCP/IP protocol stack, this is not practical for embedded environment. This paper proposes a protocol optimization program from the main implementation of the protocol functions, which reduces the code size of protocol stack, and reduces the redundancy of the protocol functions.This paper proposes a memory management strategy base on the memory management mechanism of the standard TCP/IP protocol stack, which is dividing into geographical firstly, and then dividing into sub-block partition, prefetching the memory firstly, and then executes the operation.According to the resource constraints of embedded systems and the needs of web server, this paper proposes a optimization principles about TCP protocol finite statmachine, redesigns the TCP protocol finite state machine, which reduces the connection status of the redundancy and the complexity of the packet flow path, improves the utilization of the connection and system resources.Finnaly, this paper uses ping tool to test the network performance and communication function with the web server machine. Througn and Ethernet network performance comparison to verify TCP/IP protocol stack rebustness and stability, as well as the implementation of efficiency. In the entire implement ation process of whole embedded system, all the programes were written with the ARM language and C language.