PPPOE vs DHCP

Wed Jan 26 00:34:10 UTC 2011

Hey folks...

I'm meeting with a customer tomorrow (service provider, rural telco) and
we're pitching they move to a PPPOE platform most likely.  But to be fair,
I'm looking to draw up a comparison so they are "well informed" of the
pros/cons.  Has anyone done this?

I came up with the following brief start:

PPPOE vs DHCP

PPPOE Pros

----------

Allows full authentication of customers (requires username/password)

Allows control over customer connections (suspend accounts, create accounts
etc)

Easily assign static IP to customer (no MAC address or CPE information
required)

Assign public subnet to customer with ease (no manual routing required)

IPv4/IPv6 fully supported on Juniper platform as required

Usage tracking (GB transfer) from radius generated data

PPPOE Cons

----------

Requires PPPOE termination router (Juniper ERX for example)

Requires Radius server(s) to assign and track customer IP assignments/usage

Customers require username/password to connect

Customers require PPPOE client software or router to connect

8 bytes MTU overhead

DHCP Pros

---------

Simplistic - plug and play 90% of the time

No MTU overhead, full 1500 MTU frame size

DHCP Cons

---------

No authentication occurs (anyone physically connected can use Internet
generally)

No user tracking without tracking customer CPE MAC addresses

No usage tracking builtin to DHCP (GB transfer)

There are several factors involved here.  The first major thing is that we
believe the customer wants to move towards caps on their customer usage (X
amount of GB per month).  Today, they are doing static IP assignments but
the interesting thing is that the CPE they have control over today (Comtrend
routers with DSL modem builtin).   I know there's not always a good vs bad
here but looking for opinions from folks who may have already done this
comparison for a "boardroom discussion"....

Thanks ;)

Paul