From: gvb@telly.on.ca (George VandeBunte)
Newsgroups: comp.dcom.modems
Subject: Re: ZyXEL voice and flow control
Keywords: ZyXEL voice flow control
Date: 6 Jan 93 15:14:18 GMT
Organization: Somewhere just far enough out of Toronto


 
>>ZyXEL modems use XON/XOFF in voice mode. I'd appreciate to
>>see a new ROM revision supporting
 
>>1.) Proper RTS/CTS flowcontrol in voice mode
 
This would be OK, however the current method is not unreasonable
and should not inhibit you from developing your voice application.
 
When one is sending voice, it is prudent to read information from
the DCE (modem) since the modem will be decoding the DTMF buttons pushed.
The information is shielded by <dle>.  Thus a program should look
for <dle> shielded xoff, xon, 0, 1,2,3,4,5,6,7,8,9,#,*,c(t-30 signal),
b(busy),
or <etx>, VCON.  This is one of the nice features of the voice, that
you can be decoding DTMF information both on sending and receiving
voice.   
In summary, the program should already be looking for characters, so
it can also look for xoff, and if your style of programming is to write
modular code to handle this DCE communication, it shouldn't be too
difficult to put in a pause xoff/xon.
 
 
>>2.) Reliable DTMF recognition
 
 I believe the engineers have been listening, because on the version
 I am testing, the DTMF recognition is much faster--The modem recognizes
 the numbers as fast as I can push them (when transmitting also).
 
 We have suggested also recognizing a dial tone.  However one could recognize
 this by examining the received voice since it is a constant monotone.  
 One problem
 with this is that different countries have different dial tones. Perhaps
 a simple software routine (not necessarily in the modem) could recognize
 any constant (mono)tone of say 6 seconds, and thus one could disconnect.
 
 
 
>>3.) Reliable at&d3 mode (*really* hangup on DTR->low)
 
 A DTR problem was recently fixed --when DTR and RTS dropped at the same
 time the modem wasnot hanging up.  (5.04x)  (by the way be sure DTR is
 not going low when you are changing the parameters or changing the
 parameters may have lower priority than resetting to default on DTR low.
I think this is an example of the intention to aggressively reset on DTR low.)
 
>>4.) Adjustable volume gain in voice mode
 
 Unfortunately, the speaker/ amp in the modem is not a 50 watt job , so I am
 not sure this will solve the voice volume. Of course, the voice files
 can be played on the pc speaker etc also-- but same problem. You get a nice
 volume listening in on an extension phone/ speakerphone .  The speaker got
 bigger a few months ago-- I think they are trying in this area.
 
 
 
>One more thing I would add to the list, this one really annoys me...
 
>5.) Recognize and report DTMF while transmitting voice.  This is really needed
>    for proper voice mail so that while playing your greeting the call can
>    enter DTMFs to get to a mailbox, without having to listen to the entire
>    greeting.
 
As stated above, this works very well.  I agree this is important, and many
people seem to think it is not implemented.  
 
>How can we report this to the ZyXEL engineers?  
I believe they have their ear near the ground already.
 
I work for OCOMP which provides ZyXEL modems /etc in Canada
OCOMP   Optimizing COMPuters   gvb@telly.on.ca
 
-- 
416 5341508
.
Newsgroups: comp.dcom.modems