Which Layer 2 protocol encapsulation type supports synchronous and asynchronous circuits and has built-in security mechanisms?
A. HDLC
B. PPP
C. X.25
D. Frame Relay
Answer:B
Which Layer 2 protocol encapsulation type supports synchronous and asynchronous circuits and has built-in security mechanisms?
A. HDLC B. PPP C. X.25 D. Frame Relay