说明：  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。
(This paper describes the design and implementation of lwIP. The protocol implementation and the algorithms and data structures used in the subsystem, such as storage and buffer management systems, are described. Also included are the LWIP API reference manuals and some code examples using LWIP.)