[H-GEN] ADSL2+ modems

[Greg Black]

On 2008-08-01, David Seikel wrote:

> I will upgrade to ADSL2+ soon (well, sooner or later).  I'm wondering
> what is the best modem to use.  I just want a basic modem, all the fancy
> stuff (firewall, routing, etc.) will be done by an Ubuntu box (currently
> Edgy Eft, but likely to be upgraded to the latest Ubuntu soon).
> Obviously needs to work well with Ubuntu, though the modems just use
> PPPoE?  PPPoE I already have working with my current Internet
> connection.

My take on this is that they are just throwaway items that can generally
do the basics satisfactorily and that careful shopping around is a waste
of time.

However, having now had experiences with four different ISPs and five
different modems, I have learned one thing: it is common, maybe even
usual, to have "issues" when setting up a new ADSL service (any variety
of ADSL).  And, since such services involve the ISP, the infrastructure
provider (who may be the ISP but often is not), the customer, the
exchange hardware, the modem and the customer's computer (in particular
its operating system), there are a whole lot of places for people to
point the finger at somebody else.  You don't have control over much of
this, but in my experience if you use a modem that is on the ISP's
"supported" list (preferably supplied by the ISP), you avoid a lot of
the troubles in getting things working as it's easier for them to do
remote diagnosis on something they are familiar with.

Once things are working, you need to change the default password, turn
off remote management access, and put it into bridging mode so that your
internal computer can manage the PPPoE, NAT and, if you like that
poison, any firewalling.  I also turn off the DHCP server that they all
seem to have.

In general, once your service works, I think it's best to let the modem
handle the bits going over the wire and to do everything else yourself.
Just having an open source OS in the modem is no guarantee that it will
behave as you'd like.

I've done this when the OS on the inside of the modem has been FreeBSD,
OpenBSD, Ubuntu, OS-X and Solaris.  All have managed just fine.  I won't
bother to list the modems, as many of them are now obsolete and they all
seem essentially equivalent,

Greg