PPP , SLIP , PPPoe

The key difference between PPP and SLIP are the following:-

PPP is replacing SLIP

PPP and SLIP , both are dial up protocol

PPP and SLIP , both can be dial up through serial line , like POTS

PPP can be dial up on POTS and ISDN wire/line

PPP and SLIP are used to dial up from LAN to ISP and later connect to WAN .

PPP is used to connect the starting point of the WAN to the ending point of the WAN

PPP has encryption , compression and authentication features .
But , SLIP do not have above features


PPP provide error checking but SLIP do not provide error checking

PPP can be used in multi protocols like it can send FEW PROTOCOLS on the SAME WIRE. These few protocols are referring to TCP/IP , IPX/SPX , Appletalk . BUT , SLIP only is used on TCP/IP .

PPP
(Point-to-Point Protocol)

The communications protocol used to dial up the Internet over a serial link, such as a POTS or IDSN line.

PPP is replacing the SLIP protocol.

PPP establishes the session between the user's computer and the ISP using the Link Control Protocol (LCP),

PPP handles authentication (PAP, CHAP, etc.), compression and encryption.


PPP can multiplex ( combine ) different protocols over the same circuit ( same wire )

PPP can run on any full-duplex link from POTS to ISDN to high-speed lines (T1, T3, etc.).

It can also be used to replace a network adapter driver, allowing remote users to log on to the network as if they were inhouse.

PPP can hang up and redial on a low-quality call.

Over ISDN, PPP uses one 64 Kbps B channel for transmission.

The Multilink PPP protocol (MP, MPPP or MLPPP) bridges B channels for higher speed.


PPPoE
(Point-to-Point Protocol Over Ethernet)

A method for running the PPP protocol, commonly used for dial-up Internet connections, over Ethernet.

Used by DSL and cable modem providers .

PPPoE supports the protocol layers and authentication widely used in PPP and enables a point-to-point connection to be established in the normally multipoint architecture of Ethernet.

A discovery process in PPPoE determines the Ethernet MAC address of the remote device in order to establish a session.


SLIP
(Serial Line IP)

A communications protocol for dial-up access to TCP/IP networks.

It was commonly used to gain access to the Internet

It also can be used to provide dial-up access between LANs.

SLIP transmits IP packets over any serial link (dial up or private lines).

SLIP has been mostly superseded by the Point-to-Point Protocol (PPP).