What is the difference between PPPoE and PPPoA?
Point to Point Protocol over Ethernet (PPPoE) and Point to Point Protocol over ATM (PPPoA) are both technologies that offer a provider the opportunity to roll out broadband services. This document will show why PPPoE should be chosen over PPPoA.

Advantages of a PPP based broadband service

Both PPPoE and PPPoA offer many of the same advantages; to begin we'll exam the mutual advantages they share.

• End user authentication to the network, forces the end user to authenticate to a radius server before being allowed access to the network
• Billing options, gives the provider the ability to offer different billing options, by time, by data, unlimited or by services purchased
• IP address conservation, a provider can limit the number of IPs a specific user can receive or can force a user off the connection at will
• Wholesale business model, a provider can choose to rent the “local loop” to another provider who can intern sell access to a user
• Trouble shooting, a provider can easily tell what users are on or off on a per user basis
• Scalable, all authentication, authorization, and accounting can be handled for every user using existing Radius server
• Invisible to end user, both can be integrated in the Customer Premise Equipment CPE making the connection process invisible to the end user – though we do recommend they stay off the CPE but it is easily done and PPPoA is traditionally only on the CPE
• Service Selection, both can be used to offer multiple services and service selection

Negatives of PPPoA

PPPoA has negatives that are not present in PPPoE, but PPPoE has no negative features that are not also present in PPPoA, we'll exam the negatives of PPPoA here.

• Only a single session per CPE can be established. In PPPoE we offer the ability to log in to multiple services or create multiple sessions all at the same time over the same line
• CPE setup and access, in general PPPoA must be configured on the CPE itself, PPPoA software is not available on platforms. Either the CPE must support PPPoE or an ATM network interface must be installed in the PC. ATM network interface cards are expensive and both can be difficult for an end user to configure. Once an end user has the ability to configure the CPE it opens up the problem for incorrect configurations making trouble shooting by the provider very difficult resulting in increased support costs
What if the CPE was pre configured by the provider? This leads to increased fulfillment costs. The provider would then have to configure each CPE separately to enter the customer’s userid and password and loses the ability to batch process the CPE

Positives only found in PPPoE

PPPoE has positive features that can not be found in PPPoA, we'll look at those now.

• Brand management, by having the customer use software to log on and off they force the user to see the providers brand, logo or company name. Word of mouth is the strongest form of advertising
• Increased revenue opportunities, with PPPoE we can offer the ability to log in to multiple services or create multiple sessions all at the same time over the same line. What do we mean by multiple services? How about a special account for a child that gives them G rated access only? How about a dedicated movie or music server?
• Ease of support, PPPoE software has troubleshooting and help files built in to the application. If an error occurs the error message can be present to the end user with a possible resolution preventing the customer from ever having to call the provider for help. In PPPoA everything is done in the CPE meaning when a problem occurs the only notification is lights on the CPE which tell a user nothing
• End User Familiarity, client side software present users with the familiar look and feel of dial-up which if purchasing a broadband service means they are almost 100% familiar with the dial-up look and fee reducing their learning curve to use the new service
• Works in existing environment, if a provider already offers an Ethernet based service PPPoE can be implements without changing the existing CPE, as mentioned above PPPoA needs an ATM interface

Negatives found in PPPoE

The only negative that is ever raised only found in PPPoE is that you must have software installed on the client side. As shown above this is actually a positive that needs to be reinforced to a provider.

Key reasons why PPPoE should be used over PPPoA

Above we've shown the shared advantages of both, the major disadvantages of PPPoE and the Major advantages of PPPoE. The items that need to be remembered are the advantages that PPPoE offers to a provider that PPPoA does not: Brand Management, Revenue Generating Options and Decreased Call Center Support.