PPPoX (''PPP over X'') designates a family of encapsulating
communications protocol
A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any variation of a physical quantity. The protocol defines the rules, syntax, semantics (computer science), sem ...
s implementing
Point-to-Point Protocol
In computer networking, Point-to-Point Protocol (PPP) is a data link layer (layer 2) communication protocol between two routers directly without any host or any other networking in between. It can provide loop detection, authentication, transmissio ...
.
Specific implementations:
*
PPPoE
The Point-to-Point Protocol over Ethernet (PPPoE) is a network protocol for Encapsulation (networking), encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. It appeared in 1999, in the context of the boom of DSL as the solu ...
: PPP over
Ethernet
Ethernet ( ) is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 198 ...
– which can use
802.1q VLANs
*
PPPoA
In computer networking, the Point-to-Point Protocol over ATM (PPPoA) is a layer 2 data-link protocol typically used to connect domestic broadband modems to ISPs via phone lines. It is used mainly with DOCSIS and DSL carriers, by encapsulating ...
: PPP over
ATM
*
PPTP
The Point-to-Point Tunneling Protocol (PPTP) is an obsolete method for implementing virtual private networks. PPTP has many well known security issues.
PPTP uses a TCP control channel and a Generic Routing Encapsulation tunnel to encapsulate P ...
: PPP encapsulated over
GRE with a parallel control connection and some optional encryption
*
L2TP v2 (and its ancestor
L2F): PPP sessions multiplexed within tunnels and transported over
UDP
Tunneling protocols
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