LWIP是TCP/IP协议栈的一种实现。LWIP的主要目的是减少存储器利用量和代码尺寸，使LWIP适合应用于小的、资源有限的处理器如嵌入式系统。为了减少处理器和存储器要求，lwIP可以通过不需任何数据拷贝的API进行裁减。

本文叙述了lwIP的设计与实现。叙述了协议实现及子系统中所使用的算法和数据结构如存储和缓冲管理系统。还包括LWIP API的参考手册和使用LWIP 的一些代码例子。-LwIP is TCP/IP protocol stack as a realization. LwIP main purpose is to reduce the memory utilization and code size, so lwIP suitable for small, resource-limited processor such as embedded systems. In order to reduce the processor and memory requirements, lwIP can copy any data without the process of reducing the API. This paper describes the Design and Implementation of lwIP. Describes the protocol and subsystems used in the algorithms and data structures such as storage and buffer management system. LWIP API also includes a reference manual and use lwIP some code examples.