AWAITING FEEDBACK Double DTMFs from some phones

[Alok Nath]

I have an iPhone and a dumb phone. When my iPhone is talking to my PIAF extension, and the iPhone sends DTMF, all works fine. But when the dumb phone tries to do the same, several digits are duplicated.

For example, if the user presses 1234, the PIAF recognizes as 11223344 or 1223344 etc. it is unpredictable.

Is this a problem with the dumb phone or something I can adjust in PIAF?

The dumb phone is able to access IVRs of other commercial companies without problem.

Please help!

 

[atsak]

Are you on a SIP trunk or a POTS line?

 

[Alok Nath]

Sorry for missing that detail. I tested the above problem using two ways. One, a Google Voice inbound route created by Google Chan Motif. And Two, an IPKall inbound DID through anonymous SIP.

 

[atsak]

So how's the dumb phone connected exactly? What does "talking to my PIAF extension" mean? So if you call your DID from the iphone it's fine . . . is the dumb phone a POTS phone or a phone connected to a PNA or ??

 

[Alok Nath]

My dumb phone is a cheap cell phone. All it can do is make phone calls.

By talking to my PIAF extension, I mean calling my DID from this phone, or the smartphone, having a conversation, and also sending some DTMFs and listening (by the ear) on the extension. smartphones (iPhone, Android etc) as well as dumb phones are able to support a human conversation. A smartphone is also able to send DTMFs and I can hear them correctly on the PIAF extension. But when a dumb phone tries to send DTMFs I can hear one to three tones per DTMF sent.

This same dumb phone works perfectly with IVRs of other companies such as banks and is able to correctly provide numerical inputs such as account numbers. I have tried 2 brands so far. LG and Samsung.

 

[atsak]

What's your DTMF mode in your trunk configuration set to if anything? (rfc2833, inband, etc?)

 

[jroper]

Hi

We used to see these symptoms on voip phones where more than one DTMF type had been set, e.g. RFC2833 and inband. Although this may not be the precise problem in your case, it may give you a clue where to look.

Furthermore, you can add dtmf logging to the asterisk console or "full" log which may help identify the problem.

Joe

 

[Alok Nath]

Thank you very much for your hints. For Google Voice trunks, where would be the place to edit the DTMF mode settings? The trunk that GV Chan motif module creates does not offer a place to edit the DTMF mode.