- synchronous serial
- asynchronous serial
Explanation: PPP can operate across any DTE/DCE interface in either asynchronous or synchronous bit serial mode. The high-speed serial interface (HSSI) developed by Cisco Systems and T3 plus Networking is a DTE/DCE interface that provides high speed connectivity. Asynchronous serial interfaces and synchronous serial interfaces are also DTE/DCE interfaces.
More Questions: CCNA 4 Chapter 2 Exam Answers