在TCP、HDLC等能提供可靠通信服务的通信协议中，需要使用定时器来对数据包的超时重发进行计时。

In reliable protocols such as TCP and HDLC, a timer is required to timing for data package overtime retransmission.

youdao

在TCP、HDLC等能提供可靠通信服务的通信协议中，需要使用定时器来对数据包的超时重发进行计时。

In reliable protocols such as TCP and HDLC, a timer is required to timing for data package overtime retransmission.

youdao