Which protocol provides an encapsulation method for sending IP packets over a serial link?

A.
Point-to-Point Protocol (PPP)

B.
Transmission Control Protocol (TCP)

C.
Post Office Protocol (POP)

D.
User Datagram Protocol (UDP)

Explanation:
There are two common protocols used to encapsulate IP packers across a serial link: SLIP (Serial
Line Interface Protocol) and PPP. Slip is rarely used anymore, PPP is commonly used today. SLIP
& PPP runs at the physical layer (Layer 1). This allows PPP (because of the control information
that PPP has that SLIP does not) to also transport non-IP traffic such as IPX and NetBUEI.
Incorrect Answers:
B: TCP is a transport layer protocol (Layer 4). TCP can be passed through a PPP link.
C: POP is used to receive mail from a mail server. POP is an application level protocol (Layer 7),
and can be passed through a PPP connection.
D: UDP is a transport layer protocol (Layer 4). UDP can be passed through a PPP link.