No valid handle from lineGetID(.. "comm/datamodem") after dialing remote. Please Help.

Tech-Archive recommends: Fix windows errors by optimizing your registry

From: Karsten Strobel (strobel_at_ait-augsburg.de)
Date: 02/12/04 

Date: Thu, 12 Feb 2004 12:16:20 +0100

Hi All,

I have a big problem with accessing remote modems and I really hope someout
here can help me.

I have a data modem attached to a Windows NT Server 4.0 SP6a. I want to do a
data call from a client PC (Windows 2000 Prof) using that modem over the
RemoteSP.TSP. All what I am doing seems to work well when I'm using a local
modem, but the remote case gives me headache.

After successfully calling lineMakeCall(), having received the LINE_REPLY
for that call, I receive a LINE_CALLSTATE callback with
dwParam1=LINECALLSTATE_CONNECTED. So far, no problems.

Then, when I lineGetID() with dwSelect=LINECALLSELECT_CALL, hCall=my call
handle and lpszDeviceClass="comm/datamodem", I can access the comm. handle
(hComm) and the device name string from the returned VARSTRING structure.
The hComm handle seems to be a reasonable value (something like 304 or 411
or so), but in fakt it is not valid.

Of course, I cannot really expected to get a hComm handle of the
communication port which I can directely access from the client, since the
hardware is connected to the server and is not local to the client. I was
expecting to get something like a named pipe handle which would allow me to
transparentely communicate over the modem using ReadFileEx/WriteFileEx as I
would do with a local device. However, every such call to
ReadFileEx/WriteFileEx ect. fails with a "invalid handle" error result.

So what kind of a hComm handle does the RemoteSP.TSP give me? How can I use
it or what must I do in order to send or receive data to or from the
connected data modem?

Thanks for your help!!

Best Regards
Karsten

Relevant Pages

  • Re: lineMonitorMedia for detecting modem-fax
    ... "Flopik" schrieb im Newsbeitrag ... > A data modem session on the call. ... > be used as a heuristic to decide that this might be a data modem call. ... * Please post all messages and replies to the newsgroup so all may ...
    (microsoft.public.win32.programmer.tapi)
  • Re: [opensuse] vote for the 10.3s slogan (now were getting OT)
    ... (I honestly don't remember the 300-acoustic coupler device much.) ... My first modem was 300B, but it was connected to the phone jack, so I ... one slightly used 75bd data modem ... has power plug, line cord, 25pin serial port, six globes (showing line on, link on, data transfer, in band, fault condition and power on ...
    (SuSE)
  • Re: Dialin to Fedora Core 3 from Windows
    ... The modem initialization can be in mgetty.config using ... > you're right that it has to be something in the serial port configuration ... for the serial device used by the modem. ... >> when using the Best Data modem. ...
    (comp.os.linux.networking)
  • Re: lineMonitorMedia for detecting modem-fax
    ... A data modem session on the call. ... For an incoming data ... the application can typically make no positive detection. ...
    (microsoft.public.win32.programmer.tapi)
  • Re: lineMonitorMedia for detecting modem-fax
    ... A data modem session on the call. ... For an incoming data ... the application can typically make no positive detection. ...
    (microsoft.public.win32.programmer.tapi)