- The X.25 protocol.
- Cisco, Ansi, and Q933a.
- 10, sixth.
- True.
- Backward Explicit Congestion Notification (BECN): Frames in the direction opposite of the frame transmission experienced congestion; Forward Explicit Congestion Notification (FECN): Congestion was experienced in the direction of the frame transmission.
- False.
- NCP, LCP, and HDLC.
- ppp authentication chap.
- The show interface serial [number] command.
- PAP, CHAP.