nelson@wpd.sgi.com (Nelson Bolyard) (07/30/90)
It is possible to defeat call waiting for the duration of an incoming call.
The following method works well, and was explained to me by a representative
of Pacific Bell. To use this method, one must have the 3-way calling
feature in addition to call waiting.
1. Answer the phone. Tell caller to wait for a few seconds.
2. Flash the switch-hook and get a second dial-tone (this is the
step that doesn't work unless you have 3 way calling).
3. Dial *70 (or whatever the call waiting defeat sequence is in
your area) and wait for the confirmation tone (3 quick beeps of
dial-tone sound).
4. Flash the switch-hook again and complete the phone call with your
caller without any further call-waiting interruptions.
Now we come to my problem and question. I want to do this with my Telebit
T-2500 modem on incoming modem calls. In order to dial in to work, I have
to call a call-back unit which then calls me back at home. I can easily
defeat the call-waiting feature for the outgoing call, but so far I have not
been able to defeat call waiting for the incoming call. I have my S10
register set up rather high so that the call-waiting beep doesn't break my
connections, but unfortunately, it usually causes my computer at work to
think it's seen a large burst of random characters, which does nasty things.
I lost some files this way once when the string rm appeared during one of
these bursts. Some pretty gnarly mail got sent this way too 8-(.
I have tried the following, without success:
1. while connected (incoming call) send +++, get OK from modem.
2. send ATX3DT!W*70W!;O1
According to my T2500 reference manual, this means as follows:
AT get modem's attention
X3 don't wait for dial tone before proceeding to dial.
D Dial
T using Tones
! flash
W wait for dial tone
*70 defeat call waiting
W wait for confirmation tone
! flash again
; terminate dialing sequence without waiting for
answer, and remain in command mode.
O1 go into data mode, retrain.
The problem is that the D command "Dial" causes the modem to send back
the message "ERROR". In order to find out what was causing the "ERROR"
string, I tried removing characters from the string until the ERROR went
away. I changed to using X3 before answering the call (which I do
by typing ATA) and then I tried reducing the dial string. I finally got it
down to the point where I just sent ATD and I got ERROR. So I figure that
the modem knows it's got a call going, and just doesn't want to do any
dialing - no way no how. It's gotten too smart for it's own good.
If you know of some magic incantation which will enable my modem to
cooperate and dial during the call, I'd very much appreciate it!
Please reply via email to an address below, and I'll summarize if anything
works!
-------------------------------------------------------------------------------
Nelson Bolyard nelson@wpd.sgi.COM {decwrl,sun}!sgi!whizzer!nelson 415-335-1919
-------------------------------------------------------------------------------