Both PPPoE (Point-to-Point Protocol over Ethernet) and PPPoA (Point-to-Point Protocol over ATM) are technologies that enable service providers to run their broadband services. However, if looked at closely you’d realize that it makes much more sense to use PPPoE over PPPoA.

Some common advantages

Let’s go over some of the mutual advantages that these two protocols share:

Service selection freedom - Both these protocols can be utilized for offering different services and provide a great deal of service selection freedom to end users.

Troubleshooting - Providers can easily figure out the users who’re on or off the network.

Conservation of IP addresses - Providers are given the ability to limit the IP addresses issued to the specific users, or can even force users to disconnect.

End user authentication - Makes it mandatory for users to authenticate to a particular radius server before being granted network access.

Wholesale business model - Providers are allowed to rent local loops to other providers who can then sell network access to the end users.

Flexible billing options - Allows providers to use different billing options based on data, time, unlimited usage or purchased services.

Scalability - Accounting, authorization and authentication can be done for any number of users on the existing radius server.

PPPoA Negatives

There are some negatives in the PPPoA, which are absent in the PPPoE. However, the only negative that’s present in PPPoE is also there in PPPoA.

Let’s go over the PPPoA negatives as follows:
- Only one session per CPE is allowed in PPPoA. While in case of PPPoE, users are allowed to create multiple sessions on the same line at the same time or can also log into different services.
- PPPoA needs to be configured on CPE only and its software is unavailable on platforms. CPE must either support the PPPoE or the PC must be equipped with an ATM network interface. We all know that ATM network interface cards can be expensive and configuration of both the protocols can be difficult for end users. If the end users are provided the flexibility of configuring CPEs, any incorrect configurations may make troubleshooting very difficult for the providers, thus leading to higher support costs. Many people question why CPE can’t be preconfigured by providers? Doing so can result in higher fulfilment costs. Providers would need to configure every CPE separately and enter the unique client user IDs and passwords for all the users, doing away with the CPE batch processing.

PPPoE Positives

Following are some positives that are present only in PPPoE and not in PPPoA:

Better support – PPPoE software have inbuilt troubleshooting abilities and help files which can present error messages to the end users, along with their probable solutions, thereby preventing the customers from reaching out to the provider for assistance every time. However, in PPPoA, everything needs to be done in CPE, implying that whenever a problem occurs, all that a user would see is lights on the CPE and nothing else!

Better compatibility – In case a provider is already offering some Ethernet-based service to the end users, PPPoE implementation can happen without making any changes to the existing CPE. On the other hand, PPPoA would require an ATM interface.

Better brand visibility – By forcing the end users to log on and log off from the network, the providers make them see their company, logo or brand name. This creates grounds for far better brand visibility.

Better familiarity at the user’s end – Implementation of a client site software provides end users with an environment that is quite similar to the conventional dial-up service. Hence their familiarity is normally much better and the learning curve is also not too steep.

More revenue opportunities – In case of PPPoE, providers can allow users to log into different services, or even create multiple sessions at the same time on the same line. This tremendously increases the scope of revenue opportunities. Children can be given special accounts with only G rated access; there could be a dedicated music or movie servers! Hope you get the drift!

PPPoE Negatives

The only negative present in PPPoE, which is also there in PPPoA is that it’s mandatory for the software to be installed at the client end. However, as explained above, this may actually function as a positive for the providers!

Why PPPoE over PPPoE?

As explained above, there are some shared benefits of both PPPoE and the PPPoA. However, the many negatives of PPPoA far outweigh the only negative present in PPPoE. Hence, PPPoE should be the way to go for both providers and end-users!