[NTLUG:Discuss] ADSL Configuration Questions

[Johnie Stafford]

>>> On Thu, 24 Feb 2000 11:36:00 -0600, "Dan Carlson" <dmcarlson at prodigy.net> said:

 dc> I am in the process of getting an ADSL line from GTE with DirectLink as the
 dc> ISP.  I have received the hardware package from GTE and the configuration
 dc> info email from DirectLink.  GTE is not scheduled to turn service on until
 dc> 3/9.

I've been using DirectLink for just over a year now. I've only had 2
outages that lasted more than a few mins. And both of those were GTE
problems. They are pretty Linux friendly. I don't think they could
help me with any config problems on my end if I had ever asked them,
but they have no problems at all having Linux on the other end of the
connection. And I think the techs like it because linux gives you more
diagnostic tools when you have troubles, so you can tell them EXACTLY
what's happening from your end. 

Oh, when the GTE guy comes to connect you up. Don't expect them to be
able to answer any questions you might have. When I asked a question
of my installer I got, "I don't know, all I know is I've got to get
three green lights on the modem before I can leave."

 dc> My main question is: How do I configure Linux to use the Fujitsu/Orckit ADSL
 dc> modem as its internet gateway?  This modem is an external box that plugs
 dc> into the phone line and into a 10baseT ethernet connection.

Just configure it like a plain LAN connection. DirectLink has given
you everything you'll need to know to do the config.

 dc> I currently have two ethernet adapters in my server supporting 100baseT and
 dc> 10baseT subnets.  I route between them and I use an automated PPP dialup
 dc> script and IP masquerading to provide internet access to the clients on the
 dc> two subnets.  This all works great.

 dc> Can I put the ADSL modem on the existing 10baseT subnet, or do I need to add
 dc> another 10baseT interface and dedicate it to the modem?  I think I
 dc> understand how to do the latter, but I don't understand how to do the
 dc> former.  Does the interface the modem is connected to need to be dedicated
 dc> to the gateway function, or can it also be on a local subnet?

You can do either. It is possible to have different networks on the
same connection you just have to set up the routing. Although if your
10BaseT net is very heavily loaded, you might want to go with the new
interface and isolated connection.

 dc> Separate question: Is there any protocol running above IP over the ADSL
 dc> link, such as PPP?

It's just standard IP. If you think about it, you are currently
running IP over PPP. This is IP over ADSL, but the modem handles that
protocol, so you don't have to worry about it. As far as your server
is concerned, its just straight IP.

Good luck,

Johnie