If you use DSL to connect to the Internet, you may take advantage of the PPPOE system via an access concentrator. Many service providers handle this type of connection automatically via preprogrammed routers or modems, but some ISPs require you to click an icon to log in to the concentrator when you want to use your connection. In effect, a PPPOE concentrator serves as a sort of dial-up gateway for your Internet connection, albeit one that allows much greater speeds than traditional dial-up modems.
The Point-to-Point Protocol is a data protocol that allows the transfer of information packets between nodes on a network. In Internet connections, PPP serves as the bridge between IP, or Internet Protocol, and individual users' systems. PPPOE is PPP over Ethernet, a method of establishing a PPP connection using an Ethernet connection, such as the one between your computer and your DSL modem. Once established, this type of connection allows you to send and receive packet seamlessly throughout the Internet.
Many ISPs route their PPPOE connections through access concentrators. These devices allow the service providers to grant access to large numbers of users without needing to create a dedicated connection for each one. When you click the icon for the access concentrator, your DSL modem connects to the network, receiving an IP address and going online. Different systems have different methods for maintaining and terminating these connections, cutting off users either after a set period or when their Internet connections fall idle for a time. In most cases, users can click the concentrator icon once again to reconnect to the system.
Most of the advantages of a PPPOE concentrator connection lie on the service provider's side. Using this setup allows an ISP to add users without needing to increase their own network architecture, forcing more individuals to share the same pipelines. If too many people try to connect to the same concentrator, overall performance suffers, so some increase of connection bandwidth in proportion to the user base is necessary to prevent system congestion.
In addition to the hassle of having to re-establish your DSL connection, some PPPOE connections can cause problems with certain network setups. If you encounter difficulties with large file downloads, it may be due to an MTU, or maximum transmission unit, disagreement. This figure details the largest packet size that a given connection can handle and usually defaults to around 1500 on Windows systems. However, PPPOE connections require a slightly lower setting for maximum throughput. Changing the MTU setting in your router's configuration screen to 1454 may improve file transfer issues on a PPPOE connection.