Point-to-point protocol

In networking, the Point-to-Point Protocol (PPP) is a data link protocol commonly used in establishing a direct connection between two networking nodes. It can provide connection authentication, transmission encryption and compression.

PPP is used over many types of physical networks including serial cable, phone line, cellular telephone, radio links, and fiber optic links.
PPP is also used over Internet access connections (now marketed as "broadband").

Most encapsulated forms of PPP is Point-to-Point Protocol over Ethernet (PPPoE) which used most commonly by Internet Service Providers (ISPs) to establish an Internet service connection with customers.

RFC 2516 describes Point-to-Point Protocol over Ethernet (PPPoE) as a method for transmitting PPP over Ethernet

The PPPoE (Point to Point Protocol over Ethernet) protocol provides extensive user management, network management and accounting benefits to ISPs and network administrators. Currently PPPoE is used mainly by ISPs to control client connections for Ethernet networks. PPPoE is an extension of the standard Point to Point Protocol (PPP). The difference between them is expressed in transport method: PPPoE employs Ethernet instead of serial modem connection.