Let me start out by saying I am not a proponent of client software and personally avoid using it if possible. In some cases it is a consideration though. Consider the following. You have a large (Regional/National) cable/wireless/DSL deployment and resell the last mile to ISP customers. There are two potential business models for this network. (according to your marketing department) One would be to partner with your ISP customers where they resell your services targeting the residential market. DHCP will work fine in this configuration where you provide the internet transit and maintain control over the customer. The other would be to Wholesale the last mile connection to the ISP customer. In this scenario you need to hand off the end user traffic to your ISP customers. DHCP alone is not a viable option in this model. How do you get the end user traffic to the ISP and back in a pure IP environment? Policy routing, GRE, MPLS, force your ISP customer to interconnect at every location, etc.? At this point ATM and PPPoE become considerations each with its own advantages. If the service offering is business class ATM may be preferred (required by your customer) for COS/QOS. From a configuration management standpoint PPPoE has advantages especially in a residential environment as you do not need to reconfigure the PVC when the end user changes providors. In a wireless environment this becomes even more of a consideration as most of the current hardware is limited in ATM or L3 functionality... Most network designs/business models are more complex than this but I did not feel like typing that much:) I do not intend to argue one technology over another, just to point out that there are reasons PPPoE exists and is in use..... A good network design also needs to consider the business model of the company it supports.