On Wed, 28 Oct 2009 15:33:58 -0700 Walter Keen <[email protected]> wrote:
> Most aDSL modems if set to PPPoE (I think Actiontec's come this way by > default) will send the mac as the pppoe un/pw. > David E. Smith wrote: > > Opinions on this? I'd be interested in hearing the latest real world > experience for both and the direction most folks are going in. > DOCSIS cable networks use DHCP and have for a long time. If you have Ethernet based DSLAMs, they can usually do the a number of tricks (e.g. Option 82 insertion into the DHCP request) that would make a DHCP ADSL deployment no harder (or easier) than a DOCSIS cable network. It seems to me that the fundamental purpose of PPPoE is to be able to uniquely identify the customer for billing/provisioning purposes. Even though you only need to be able to do that at the start of their session, with PPPoE you pay an 8 byte per packet overhead, on _every_ packet sent and received by the customer. Other methods of distinguishing the customer, e.g. Option 82, static DHCP mapped to a customer MAC address, or possibly 802.1x if it were available, have much, much lower overhead. I think PPPoE really only exists to make ADSL look like high speed dial-up, so that ISPs dial up backend systems didn't need to be changed when ADSL was introduced. That was a valid concern in the past, but with existing solutions or models such as the DOCSIS Cable methods, and Ethernet based DSLAMS, I'd suggest avoiding PPPoE if you can. > I can't speak to which would be better on copper specifically, but in > > > general I'd favor DHCP over PPPoE. Either way, most of the back-end stuff > will be similar (you'll need a way to authenticate users, turn them off and > on, et cetera); the differences won't be all that big. Either you're storing > their MACs in a database, or their port assignments and VLAN tags, or their > usernames and passwords. > > With PPPoE, however, the end-user can't just plug in and go - they'll have > to configure their PC, or a DSL modem, or something. That means a phone call > to your tech support, most likely. In many cases, DHCP can lead to > plug-and-play simplicity, which means they don't have to call you, and you > don't have to answer their calls. Everyone wins. :) > > David Smith > MVN.net > > > -- > > > Walter Keen > Network Technician > Rainier Connect > (o) 360-832-4024 > (c) 253-302-0194
