DTMF Issues on PRI Gateways
If you are experiencing issues with the UCX IVR functionality not recognizing or responding to DTMF key presses from the calling party, or with far end IVR systems not properly recognizing DTMF from UCX extensions, you may need to adjust the DTMF signaling method used on one or both directions of the SIP trunk connection between the UCX and the PSTN gateway card.
Both the UCX and the Gateway support three different methods for communicating DTMF across the SIP trunk:
- RFC2833
- Inband
- SIP “Info”
Settings for the DTMF signaling method are located as follows:
On UCX
- Navigate to the PBX / IP Trunk Assistant
- Click on the DTMF Mode drop-down item
- Select the signaling method of choice
On PRI Gateway card
- Navigate to the VOIP / VoIP Endpoints and Edit the connection to the UCX
- Navigate to the Call Settings section and click on the DTMF Mode drop-down
- Select the signaling method of choice
Typically the settings mirror each other with both defaulting to RFC2833, but depending on the nature of the network one setting may work better in one direction than the other. Changing the setting on the UCX will affect how DTMF is transmitted to the PRI Gateway card and out the PSTN network to the far end. Changing the setting on the PRI Gateway card will affect how DTMF from the PSTN is transmitted from the PRI Gateway card to the UCX.
E-MetroTel has found that if a change is required to resolve DTMF, it is often resolved by setting the UCX to Inband and INFO on the Galaxy PRI gateway card.
DTMF Issues on FXO Gateways
If you are having DTMF issues with FXO gateway cards, you may need to make the following adjustments.
On UCX
- Login to UCX Administration
- Navigate to PBX -> IP Trunk Assistant
- Edit SIP trunk for the FXO Gateway and verify DTMF Mode is set to rfc2833.
On FXO Card
- Login to FXO Administration
- Navigate to Advanced Configuration -> Analog Settings
- Gradually increase the FXO HW-RXGAIN as needed.
DTMF Issues on Legacy Dahdi PSTN Trunks
If you are having DTMF issues with your PSTN trunks, you may need to adjust the dtmf option. Perform the following steps to change the global setting for your PSTN trunks:- Login to UCX Administration
- Navigate to System -> PSTN Cards
- Go to the Settings section located at the top right corner of the page and click on Global Settings
- Under Other Global Dahdi Settings, enter: relaxdtmf = yes
- Press the Save button
- Press the Apply Config pink bar, followed by the Reload Dahdi Configuration button.
