Point-to-Point Protocol over Ethernet
The Point-to-Point Protocol over Ethernet (PPPoE) is a network protocol for encapsulating Point-to-Point Protocol (PPP) frames inside Ethernet frames. It appeared in 1999, in the context of the boom of DSL as the solution for tunneling packets over the DSL connection to the ISP's IP network, and from there to the rest of the Internet. A 2005 networking book noted that "Most DSL providers use PPPoE, which provides authentication, encryption, and compression." Typical use of PPPoE involves leveraging the PPP facilities for authenticating the user with a username and password, predominately via the PAP protocol and less often via CHAP.

On the customer-premises equipment, PPPoE may be implemented either in a unified residential gateway device that handles both DSL modem and IP routing functions or in the case of a simple DSL modem (without routing support), PPPoE may be handled behind it on a separate Ethernet-only router or even directly on a user's computer. (Support for PPPoE is present in most operating systems, ranging from Windows XP, Linux to Mac OS X.) More recently, some GPON-based (instead of DSL-based) residential gateways also use PPPoE, although the status of PPPoE in the GPON standards is marginal.

PPPoE was developed by UUNET, Redback Networks (now Ericsson) and RouterWare (now Wind River Systems) and is available as an informational RFC 2516.

In the world of DSL, PPPoE was commonly understood to be running on top of ATM (or DSL) as the underlying transport, although no such limitation exists in the PPPoE protocol itself. Other usage scenarios are sometimes distinguished by tacking as a suffix another underlying transport. For example, PPPoEoE, when the transport is Ethernet itself, as in the case of Metro Ethernet networks. (In this notation, the original use of PPPoE would be labeled PPPoEoA, although it should not be confused with PPPoA, which is a different encapsulation protocol.)

PPPoE has been described in some books as a "layer 2.5" protocol, in some rudimentary sense similar to MPLS because it can be used to distinguish different IP flows sharing an Ethernet infrastructure, although the lack of PPPoE switches making routing decisions based on PPPoE headers limits applicability in that respect.
Q132364
network protocol
Concept
Q1172449
encapsulating
UNK
Q215179
Point-to-Point Protocol
MEDIA
Q79984
Ethernet
Concept
Q104534
DSL
Concept
Q957589
tunneling
Concept
Q214111
packet
Concept
Q11371
ISP
ORG
Q8795
IP
MEDIA
Q75
Internet
Concept
Q212108
authentication
Concept
Q141090
encryption
Concept
Q2493
compression
Concept
Q959710
PAP
Concept
Q1060131
CHAP
MEDIA
Q1146262
customer-premises equipment
UNK
Q1755130
residential gateway
Concept
Q5607
modem
Concept
Q5973191
IP routing
UNK
Q1155692
DSL modem
Concept
Q11248
Windows XP
Concept
Q388
Linux
MISC
Q14116
Mac OS X
MISC
Q3644353
GPON
UNK
Q933565
UUNET
ORG
Q498804
Redback Networks
ORG
Q1746945
Wind River Systems
ORG
Q206047
ATM
Concept
Q3050434
Metro Ethernet
UNK
Q617804
PPPoA
MEDIA
Q93312
layer 2.5
MEDIA
Q677023
MPLS
MEDIA
Q866392
Point-to-Point Protocol over Ethernet
Concept
1999-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1999
DATE
2005-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2005
DATE
2516-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
2516
DATE
+2.5^^http://www.w3.org/2001/XMLSchema#decimal
2.5
NUMBER
based on
based on
used by
subclass of