|PPPoE and You|
|Great for service providers, not so good for the home network|
PPPoE stands for Point-to-Point Protocol over Ethernet. PPPoE has become a favorite technology of broadband Internet service providers, who use it to save time and money. DSL and cable modem subscribers, on the other hand, have reason to be less enthusiastic about PPPoE.
Many home networkers do not even know if their connection to the Internet uses PPPoE. If one's cable or DSL setup requires "logging in" to the Internet, most likely this setup involves PPPoE. Many large ISPs today, like Earthlink, Pacific Bell and Verizon, require customers to connect through PPPoE to their broadband service.
PPPoE is based on an older network protocol called Point-to-Point Protocol (PPP), designed for use with slower serial lines rather than the Ethernet links used by today's broadband modems. The technical specification for PPPoE, Request for Comments (RFC) 2516, describes the details behind a complete implementation of PPPoE. Unfortunately, some ISPs' implementation of PPPoE doesn't conform fully to this specification.
PPPoE utilizes the technique of tunneling. In networking, tunneling involves the embedding of messages in one format within the packets of another format. PPPoE functions similarly to virtual private networking (VPN) tunneling protocols like PPTP (Point-to-Point Tunneling Protocol) that are also derived from PPP, although PPPoE operates at a lower level (the data link or layer two of the OSI model).
Other network protocols related to PPPoE include PPPoA (Point-to-Point Protocol over ATM), PPPoFR (Point-to-Point Protocol over Frame Relay), and many other variations on these (PPPoEoA, PPPoEoE, and so on).