[plug] Hi, Newbie here. Got some questions, please.

[Steve Boak]

Hi Lee

I'll stick to the bits I know, using the NT1 Plus II ISDN modem through USB. 
First a disclaimer - I'm using Debian, with a custom 2.4.22 kernel. On 
Mandrake, some things may be different.

[...]
> How do I get my NT1 Plus II to utilize both lines and have 128K
> DVO.  I am not particularly conversant with Init strings for modems,
> either.

You will need the acm.o (Abstract Control Model) module, hopefully it is 
included with your distro. if not, you will need to either get a version 
matching your kernel somewhere, or recompile your kernel with the 'USB Modem 
(CDC ACM) support' option turned on. This will build the acm.o module. You 
can check if the acm module already exists with 'locate acm.o', and if it is 
loaded with 'lsmod | grep acm' (without the quotes of course).

Of course you will need kernel USB support enabled, but I would expect that to 
be the case anyway these days. Check that it is enabled in the bios too if 
you are reusing an older motherboard.

When you plug in the NT1 the acm.o module should automatically be loaded. It 
will provide access to your NT1 as a standard AT modem through /dev/ttyACM0

Diagnostic messages can be found in /var/log/syslog on Debian, there should be 
a similar file on Mandrake but it may be somewhere else.

Set up your ppp connection with the usual graphical tools under Mandrake, 
using the above /dev/ttyACM0 port for the modem. Then when it is working as a 
single 64k connection, check the optional AT command strings and add the 
following for 128k with Dynamic Voice Override:
AT!T0=0!T4=1

You will have to set your firewall to allow traffic through the NT1, which 
will probably be ppp0. ifconfig will show you. I don't know how to do 
firewalls on Mandrake though.

Things to watch for: 

The NT1 does not have an internal speaker, so it is completely silent. That 
is, you will not hear any dial or modem noises when you connect.

The NT1 handles all negotiation between 64k and 128k - you will not (and 
cannot) get any information from the NT1 about it's speed once it is 
connected. It will always connect at 64k first, then add the second channel a 
second or two later to go to 128k if possible (and if DVO is enabled).

You can check if the DVO setting is working by lifting the phone off the hook 
when you are connected to the net. If all is well, the NT1 leds should swap 
from 128k to 64k, and when you hang up the phone, go back to 128k. The same 
will happen if you get an incoming phone call.

The NT1 connects really fast for a modem - around one second to dial and 
connect, so make sure you do not let it redial all night unless you are on a 
fixed charge ISDN plan (I think you are, with bigpond, but check to make 
sure) as one call per second for a few hours will get expensive! (the same 
can happen if you get the ISP phone number wrong)

Apparently the NT1 is quite susceptible to lightning strike damage if that is 
a concern to you. I don't know if that means it will sacrifice itself to 
protect your computer though :)

More information can be found on the Whirlpool ISDN/DoV forums at:
http://whirlpool.net.au/forum-threads.cfm?f=99

(Re)Building the kernel:
http://www.linuxdocs.org/HOWTOs/Kernel-HOWTO.html
http://www.digitalhermit.com/linux/Kernel-Build-HOWTO.html

Hope this helps

Steve

-- 
"Most men occasionally stumble over the truth, but most pick themselves
up and continue on as if nothing had happened." - Winston Churchill