Re: [hylafax-users] DTMF Detection Followup

[Darren Nickerson <darren.nickerson@xxxxxxxx>]

John,

That's some pretty clever troubleshooting! What you have concluded is frequently the case - touchtone pads are frequently disabled to prevent people from messing up the fax transmission. It may be configurable on your device.

DTMF-based inbound fax routing is most frequently used to pass DID/DNIS (dialed number) information down an analog (POTS) line that does not otherwise support the signaling of this information. The DTMF tones are normally generated by the PBX or other such device which does have the DID information, but can't get it to HylaFAX without doing some sort of in-band audio-based signaling after HylaFAX answers the call.

-Darren

On Oct 14, 2008, at 8:50 PM, John Dell'Aera wrote:

Hello

 

I did the following experiment as a follow up to my previous experiment with cu and DTMF detection:

 

I pressed fax start on my fax machine and waited for the long low frequency tone from my modem (AT+VTS=[200,200,500])

Then I disconnected the fax machine cable from the fax machine and connected it to a touchtone phone and dialed 1234.

I hung up the phone and reconnected the phone cable to the fax machine to let the fax transmission continue.

I received the fax in the recvq directory. I dumped the variables collected from faxrcved:

 

######################################################################

This indicates that the DTMF tones were read by faxgetty and passed to faxrcved.

######################################################################

SENDER=**********
DEVICE=modem
CIDNUMBER=1234
SUBADDR=
CIDNAME=
DESTINATION=
CALLID=

 

 

######################################################################

/var/log/syslog excerpt: This indicates that the DTMF tones were read by faxgetty.

######################################################################

Oct 14 17:25:00 EfaxServ FaxGetty[6746]: MODEM INTEL CORPORATION 537EP/537EP  PRE-Release 2.70.95.0  - Jul 26 2005
Oct 14 17:25:00 EfaxServ FaxGetty[6746]: <-- [5:ATM0\r]
Oct 14 17:25:00 EfaxServ FaxGetty[6746]: --> [2:OK]
Oct 14 17:25:00 EfaxServ FaxGetty[6746]: STATE CHANGE: RECEIVING -> RUNNING (timeout 30)
Oct 14 17:25:00 EfaxServ FaxGetty[6746]: MODEM input buffering disabled
Oct 14 17:25:00 EfaxServ FaxQueuer[6775]: FIFO RECV "+modem:RPcaf9c77f:ff"
Oct 14 17:25:00 EfaxServ FaxQueuer[6775]: MODEM modem: READY, capabilities Pcaf9c77f:ff
Oct 14 17:26:13 EfaxServ FaxGetty[6746]: STATE CHANGE: RUNNING -> LISTENING
Oct 14 17:26:13 EfaxServ FaxQueuer[6775]: FIFO RECV "+modem:B"
Oct 14 17:26:13 EfaxServ FaxQueuer[6775]: MODEM modem: BUSY
Oct 14 17:26:13 EfaxServ FaxGetty[6746]: --> [4:RING]
Oct 14 17:26:20 EfaxServ FaxGetty[6746]: --> [4:RING]
Oct 14 17:26:20 EfaxServ FaxGetty[6746]: <-- [12:AT+FCLASS=8\r]
Oct 14 17:26:20 EfaxServ FaxGetty[6746]: --> [2:OK]
Oct 14 17:26:20 EfaxServ FaxGetty[6746]: <-- [9:AT+VLS=1\r]
Oct 14 17:26:20 EfaxServ FaxGetty[6746]: --> [2:OK]
Oct 14 17:26:20 EfaxServ FaxGetty[6746]: <-- [21:AT+VTS=[200,200,500]\r]
Oct 14 17:26:25 EfaxServ FaxGetty[6746]: MODEM TIMEOUT: reading line from modem
Oct 14 17:26:29 EfaxServ FaxGetty[6746]: MODEM HEARD DTMF: 1
Oct 14 17:26:29 EfaxServ FaxGetty[6746]: MODEM HEARD DTMF: 2
Oct 14 17:26:29 EfaxServ FaxGetty[6746]: MODEM HEARD DTMF: 3
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: MODEM HEARD DTMF: 4
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: ANSWER: Call ID 1 "1234"
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: STATE CHANGE: LISTENING -> ANSWERING
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: Apply CanonicalNumber rules to "+1.650.555.1212"
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: --> match rule "[^+0-9]+", result now "+1650.555.1212"
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: --> match rule "[^+0-9]+", result now "+1650555.1212"
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: --> match rule "[^+0-9]+", result now "+16505551212"
Oct 14 17:26:30 EfaxServ FaxGetty[6746]: --> return result "+16505551212"

 

 

 

 

This result tells me that the touchtone pad on my fax machines is disabled during a fax transmission.

But that seems strange because I can tell that a lot of work went into HylaFax to support DTMF tone detection for routing.

If the touchtone pad were truly disabled on many fax machines during a fax transmission DTMF detection support would

be virtually useless. And I assume that's not the case.

 

So my question is what am I doing wrong that prevents me from sending/detecting  DTMF tones DIRECTLY FROM my fax machine?

Thank tou.

John