单项选择题
A. HDLC B. NCP C. PAP D. LAPD E. LAPB F. None of the above
Which of the following correctly describe characteristi...
多项选择题Which of the following correctly describe characteristics of PPP?（）
A. Encapsulates several different types of routing protocols. B. Supports only IP. C. Can be used over analog circuits. D. Is proprietary to Cisco E. Supports error correction.
What are some common layer 2 encapsulations for a WAN l...
多项选择题What are some common layer 2 encapsulations for a WAN link?（）
A. Ethernet B. PPP C. Token Ring D. HDLC E. Frame Relay F. POTS
Which WAN service utilizes two different encapsulation ...
单项选择题Which WAN service utilizes two different encapsulation types (one for data and one for signaling) on its data link layer?（）
A. ISDN B. Frame Relay C. ATM D. FDDI
