Re: [OT] Terrific - was: [tlug] email programs

[Tod McQuillin <devin@example.com>]

On Tue, 27 May 2003, John Limouze wrote:

> I have an  external ISDN TA that the people at NTT and
> SuSE support (my distro) tell me won't work because there are no
> drivers.

This is the standard answer you will get from large companies.  It may in
fact be true, but it so often isn't that I would ignore it straight off.

> But elsewhere (on SuSE's site for instance), I have read that no
> drivers are necessary for external TAs, just the correct init strings,
> which I took from the .inf files for windows.

In general this is 100% true.  In fact, often you don't need any
special init strings at all -- you can just treat the device as a generic
modem with a Hayes AT command set.  A lot of the hayes AT commands have to
do with things specific to modems, like error correction mode, tone vs.
pulse dial, blind dialing, etc.  Flow control is still important, but many
TAs default to the correct settings.

> No success though; with wvdial and kppp it stalls out waiting for an OK
> response to the initial AT command.

This could be because the TA is not in the right mode to allow access from
the serial port, or because the port speed is wrong, or maybe the TA is
not doing full duplex echoing so your dialer doesn't see any response.  Or
you could have a bad cable, the TA could be broken, kppp could be
broken (or misconfigured), etc.

> Kinternet tells me it's connected to an IP address that I later
> saw listed as an example in one of the Kinternet config files.

I've never used Kinternet so I can't comment on whether that's useful
information or not -- sorry.

What you need to do is start ruling out potential sources of the problem.

Start with big categories that can rule out one or more entire lines of
inquiry.  For example, if the same hardware works on the same machine with
windows, then you know everthing at least works at the hardware level and
can avoid doing things like swapping out cables.

Try talking to the TA using a communications program like tip, cu or
kermit (I particularly recommend kermit; it is a joy to use compared to
tip or cu which require editing config files which can only be understood
by careful reading of the man pages.  Of course you will also need to read
docs for kermit, but it's pretty straightforward and there is built-in
help.)

Look at the manual for your TA (or search the web for a manual).  There
should be a section describing the AT commands it accepts.  If it is at
all vaguely hayes compatible then ATE1 should enable echoing and
ATDT####-#### should initiate a call.  Type at the modem in your
communications program and see if you get a response.  If you don't, try a
different cable or a different port speed.  (you should use 8 data bits, 1
stop bit, no parity)

If you can talk to the TA, figure out how to initiate a call with it.
Read the documentation for your dialer and make sure it's set up to use
that method.

It could also be a problem with Kinternet or kppp.  Read the docs for your
pppd and chat programs and try using a ppp HOWTO to set it up without
kppp.  This will involve reading docs and editing config files, but hey,
that's what unix is about.  It won't be the last time you have to do it.

I used pppd (and 'chat' as a dialer) on linux with an NTT TA for more than
a year and I never had a problem with it (except my phone bills).
-- 
Tod McQuillin