Conference # can't hear my key presses.....

[bandit1200]

Not sure it I'm using the right words to describe.

First, the set up:  Obi100, Google Voice, Panasonic Cordless phone, all plugged in to a nice fast home internet (50/10).  Stock config using obitalk website.  Works great, calls in, calls out.

However,  when I call (from the Panasonic cordless) to a service like a conference bridge, it seems the other end cannot always hear the key-press beeps as I dial in the conference code and hit #.

Sometimes I have to do it twice. Sometimes it doesn't work at all.

Its like the volume is just a little low, or the key-press tones are a bit short or something.

Any ideas?   Would like for it to be rock solid.

What do I do....

[hwittenb]

It more than likely something to do with the voip provider and the different people they contract with to terminate your call.  The ITSP Profile has 4 different settings for the method to use for sending DTMF digits.  The default is "Auto".  The other settings are RFC2833, Sip Info, and INBAND.  Try them all starting with RFC2833.  There is also a setting X_UseFixedDurationRFC2833DTMF which by default is unchecked.  That is also a good setting to try.

Initially over an analog circuit DTMF digits were sent "inband" or part of the audio stream.  The problem with DTMF digits over a digital circuit is the analog to digital conversion and then the subsequent digital to audio conversion back again.  The frequencies are very precise and the conversion has to be right on.  There was early trouble sending digits especially using compression codecs and an "out of band" method was needed.  Initially the sip info protocol was used.  Then the RFC2833 standard for out of band transmission was developed.

The RFC2833 protocol attempts to recreate the exact length of time the key was depressed.  This in itself causes some problems hence the setting "UseFixedDurationRFC2833DTMF".