ISP Suggestions...(was Re: Re:Help With Home Server)

[Matthew M. Gamble]

> On Tue, 2 Sep 2003, Moniz wrote:
> > >There is absolutely nothing about DSL that requires an extra layer of
> > >protocols to make it act like a virtual phone call...
> >
> > Actually, I believe PPPoE was implemented to keep the phone company's
> > hands off the IP layer. Your ISP handles all of the IP and the phone
> > company just provides the pipe.
>
> That doesn't require PPPoE.  When the phone company sets up DSL service on
> your line, they tell their box "anything that comes out of this wire, send
> it to *that* ISP, he knows what to do with it".  Similarly, the ISP has a
> way to send them stuff earmarked to go into your wire.  No IP-level
> involvement by the phone company is required; IP addressing on your wire
> is a matter between you and your ISP.
>
> (The IP addresses on either end of *my* DSL link are non-routable, from
> one of the private-address blocks.  They were picked by my ISP in
> consultation with me, for our mutual convenience; the phone company was
> not involved in the discussion.)
>
>                                                           Henry Spencer
>                                                        henry-lqW1N6Cllo0sV2N9l4h3zg at public.gmane.org
>

Henry,

Just a small correction - PPPoE connects you to the Bell ATM network cloud.
>From there, you can (in theory) connect to *ANY* ISP that supports your
region.  For example, you could be an Echo DSL customer and connect to the
sympatico DSL service (it works, I've tried it) provided you have a valid
login id for sympatico.  PPPoE is used to create the 'on-demand' link from
your modem to the ISP (determined by the realm in your login id) via L2TP
tunnels.  Bells motivation for PPPoE was simple - its easier to configure
than VLAN (see below) and it allows the easy creation of different service
profiles within the same network (all based upon realmed usernames).

In the case of 3Meg VLAN DSL, it's still over the Bell ATM network, but is
done using 802.11q VLAN routing.  In this case, you are correct that you are
tied to a specific ISP, as Bell will route your VLAN id to your ISP.  This
is an actual ethernet connection, and you don't require any special software
or routers to connect.  Due to it's ethernet nature, it also becomes much
easier to assign /30 or /29 netblocks to 3Meg VLAN customers.

I hope this helps clear up some of the confusion about the difference
between PPPoE and VLAN DSL.  There are a few technical points I've left out,
but the basics are all correct.

Regards,

M. Gamble


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