This is a beta course, so its structure, chapters, and examples may continue to change.练习题 This article is being translated. Please check back soon. Previous物理层设备学习物理层设备的功能和特点，包括中继器、集线器等Next数据链路层掌握数据链路层的功能、组帧、差错控制、流量控制、介质访问控制及典型局域网协议。
