Which side of the serial connection specifies the clock rate?

In a serial connection, the clock rate is specified by the Data Communication Equipment (DCE) side of the link. DCE devices are responsible for providing timing information for the data transmission, which is critical for synchronizing the flow of data between devices on the network.

In typical serial connections, one end is a DCE device, which often connects to a DTE (Data Terminal Equipment) device. The DCE device, such as a modem or a CSU/DSU (Channel Service Unit/Data Service Unit), generates the clocking signals required for the communication between the two endpoints. Because the DCE side controls the clock rate, that is where you will configure or set the clock speed for the serial interface.

This distinction is essential in networking, especially when configuring serial interfaces on routers, as the DCE side is what manages the timing and ensures proper data transmission rates. Understanding this relationship between DTE and DCE is fundamental for CCNA candidates, as it directly relates to setting up and maintaining serial connections in various networking environments.