2 modem drivers on 1 COM port

[Tim Thornton]

Hello,
We are having problems when we try and put 2 modem drivers
onto 1 COM port.

We need this in two cases: the user may need to attach
different external modems to the COM port (e.g. GSM or
satellitte phone), or he may be using a GSM phone with
GPRS, and because the modem handling for GPRS is different
a different driver needs to be installed. These are laptop
users who cannot add additional COM ports to their
machines.

The user has 2 dial-up networking (DUN) settings, one for
each modem driver. Windows selects the modem driver to use
seemingly at random. If logging is switched on, the log is
also placed in a modem's log file at random. However the
log entry shows which modem driver is being used, and this
is always correct, so we can see when Windows is using the
wrong driver.

Has anyone else experienced this? Anyone got a workaround?

FYI, Windows 98 handles this without any problem, but 2000
said this does not work by design on the MS support pages,
and there is nothing about it in XP. Also, according to
our software engineers, Windows guidelines now stop us
writing our own modem driver to circumvent this problem.

Regards,

Tim Thornton

 

[Jason]

Actually you can add serial ports if you have a USB port. They are readily
available. You can skip this for my CDMA 'phone since the cable is a USB (to
fast serial) to Kyocera. I.E. Adds com port so I can use fast Internet
(twice that of native com port speed). Essentially it has two drivers - one
for any com port between 3 and 7 (depends on which USB socket I plug into
and a 4 port USB hub) and the one for the modem. Since you have serial
cables you would need the USB to serial cable and install that driver then
proceed with the modem installation from there.

 

[Guest]

The existing USB ports are in use. Also we don't like
using USB ports because some of the serial to USB devices
have horrendous latency problems, which means that some
software using serial ports does not operate correctly
(e.g. Iridium satellite phones). Adding a USB hub just
exacerbates the problem. We prefer to use PCMCIA serial
cards as these are much more reliable, but the PCMCIA slot
is already in use.

Also this would not solve the problem of one physical
phone needing 2 different modem installations, to switch
between GSM and GPRS. (For you Americans who haven't
switched to GSM yet, if yuo want to know more look at
www.gsm.org).

Thanks anyway,

Tim

 

[Jason]

I'm not american and Internet over x1 CDMA is faster than GPRS plus there
was other reasons why I changed.