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Voiceguide Not Hearing Dtmf

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#1 Accel 15 June 2016 - 12:22 AM

We are deploying a  Voiceguide setup that relies on DTMF input.  However, DTMF tones are not being recognized.


Pertinent information:


1. Voiceguide is installed on a Windows 2012 R2 VM in the Azure cloud.

1. Voiceguide is registered to a cloud-based Asterisk as a SIP peer, and Asterisk is configured as UDP SIP.

2. SIP Provider is Flowroute.

3. DTMF tones are configured as rfc2833.


Wireshark and Voiceguide traces attached.

#2 SupportTeam 15 June 2016 - 06:33 AM

After call is established the VoiceGuide system is sending RTP (voice data) back to Asterisk, but VoiceGuide is not receiving any RTP packets from Asterisk.


So caller would hear what is played by VoiceGuide, but VoiceGuide is not hearing anything at all from the caller. No sound and no RFC2833 packets.


Please see screenshot below that shows the SIP and RTP packets from the provided trace: (VoiceGuide) answered call from (Asterisk), and VoiceGuide is sending RTP data to, but there is no RTP from to


Suggest looking at Asterisk system, or the networking devices in between to ensure that there is connectivity between the systems to allow RTP packets from Asterisk to reach VoiceGuide.

  • sip_rtp_filtered.png

#3 Accel 15 June 2016 - 10:55 PM

We solved the issue.  You were correct in that the issue lied in the Asterisk system.  Our SIP provider analyzed a packet trace and noticed that the Voiceguide server was giving out its private IP address.  We made the adjustment in the Asterisk SIP config to NAT=YES, and two way RTP traffic began.  All seems to be well now, thank you for the assistance.