> For the complete documentation index, see [llms.txt](https://book.bsdcn.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://book.bsdcn.org/4.3-bsd-unix-cao-zuo-xi-tong-she-ji-yu-shi-xian/di-yi-bu-fen-gai-lan/2.12.-wang-luo-shi-xian.md).

# 2.12 网络实现

4.2BSD 实现的第一个协议套件是 DARPA 的传输控制协议/网际协议（TCP/IP）。CSRG 选择 TCP/IP 作为纳入套接字 IPC 框架的第一个网络，是因为 BBN（Bolt, Beranek and Newman）一个受 DARPA 资助的项目提供了公开可用的基于 4.1BSD 的实现。这是一个影响深远的选择：4.2BSD 的实现正是这一协议套件得到极其广泛使用的主要原因。后来对 TCP/IP 实现的性能和功能改进也得到了广泛采纳。TCP/IP 实现在第 12 章详细描述。

4.3BSD 的发布增加了施乐网络系统（XNS）协议套件，部分建立在马里兰大学和康奈尔大学的工作之上。这套协议用于连接那些无法用 TCP/IP 通信的孤立机器。

ISO 协议套件将是下一个加入 4.3BSD 未来版本的网络实现，因为它在美国国内外都日益引人注目。


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