DTMF in voip-to-voip

[open7]

My system is:
3CX v8
Snom 870
Spa3102
voip (CallCentric)
pstn

When I call thru the pstn line IVR DTMF works fine. When I call via the voip line, some time the receiving IVR system may not recognize the DTMF tones. I usually at that point dial out on the pstn line to make it work. Because I am using the same phone (snom) for both calls, I would assume that it is an issue with the 3CX system. Any thoughts?

 

[leejor]

DTMF can be sent over VoIP a number of ways, generally, in-band or out-of-band. It sometimes requires "playing" with the DTMF settings of the device that the tones originate from. Unfortunately, there isn't a "one shoe fits all" solution.

 

[open7]

More info on this problem. It does appear to be related to the Snom 870. I also have a Snom M3 and I can use the keys on that phone to work the IVR system sucessfully, but not on the Snom 870. Strange thing is that if I use the Snom 870 going thru the gateway to the PSTN, I have no problems.

Anyone have any ideas on how to tweak the 870 for DTMF?

 

[mbulles]

I'm using grandstream 3000 and 3140 works fine with DTMF and mobotix camera, you have 3 possible options. Make sure you test accordingly and choose the one that works best in the grandstreams config.

 

[LeonidasG_3CX]

After my best knowing works RFV DTMF best for PSTN and SipInfo (or INband) for VoipProviders...