I've set up Twilio Elastic SIP Trunking and tested the number. It works. However, DTMF is still not coming through from the assistant when the assistant presses numbers on the keypad. Only clicks come through in the audio. Here is a call log with an example: 7d1c2e13-1b18-49ed-924a-7cbb2ff91f8a

@Edpreble I'm glad to hear that your Twilio Elastic SIP Trunking setup is working. Regarding the DTMF issue, it sounds like there might be a configuration problem with the way DTMF tones are being sent. Twilio supports both in-band and out-of-band DTMF. In-band DTMF sends the tones as part of the audio stream, while out-of-band sends the tones as separate signals. Here are a few steps you can take to troubleshoot the issue: 1. **Check Twilio Configuration**: Ensure that your Twilio configuration is set to use the correct DTMF method that is compatible with your SIP endpoint. 2. **SIP Endpoint Configuration**: Verify that your SIP endpoint is configured to handle the DTMF method you've chosen in Twilio. 3. **Network Issues**: Sometimes network configurations, such as firewalls or NAT, can interfere with DTMF signaling. Ensure that your network allows DTMF signals to pass through without alteration. 4. **Twilio Support**: If you've checked the above and the issue persists, consider reaching out to Twilio support with the call log ID you've provided. They can help you investigate the issue further. If you need assistance with contacting Twilio support or any other actions, please let me know, and I'll be happy to help.

@Vapi None of these worked. Here's another example from the call log: bdb3cfb8-c13a-48e9-97c6-e2f47c8dbf12

@Edpreble I'm sorry to hear that the issue persists. Since the standard troubleshooting steps haven't resolved the DTMF problem, it would be best to escalate this to the technical support team for a deeper investigation. They will be able to analyze the call logs in detail and provide a more targeted solution. Would you like me to guide you on how to contact Twilio's technical support or is there anything else I can assist you with?

Please escalate to Vapi Support

Have the DTMF issues been fixed in vapi?

@Edpreble Allow me some time to thoroughly go through it.

Thank you. This problem is persisted for some time and I'm hoping to get it solved ASAP.

@Edpreble I have looked into the call ID shared, and we are sending the DMTF tones but considering your words I will compare it few other call ids which are following the same process. https://cdn.discordapp.com/attachments/1324931148257951786/1326142964862287912/Screenshot_2025-01-07_at_16.24.38.png?ex=677e5a61&is=677d08e1&hm=6f0be5d03134f86235e4674b6cf94fadcacc909a1e3db1e1e82d356439bd7f06&

If you call the number and ask it to press any key, you'll hear that there is no DTMF tones, only "click" sounds.

@Edpreble I have replied you over two tickets with the same issue but I'll drop the same message here as well. Currently, we don't have IVR navigation fully set up, but we're actively working on mapping it out. Regarding the timeline, this feature should be available during early Q2 of this year. In the meantime, you can implement IVR navigation programmatically using keywords or phrases, and then programmatically transfer the call to the Vapi number. You can use Twilio with GPT for IVR navigation and then transfer the call to VAPI.https://github.com/twilio-labs/call-gpt

@User Thanks for the reply. It sounds like the Elastic SIP Trunk is not going to solve the problem for DTMF. Would it be possible for me to prompt the assistant to load and play an audio file that contains the specific tones needed? Perhaps through the use of a tool call?

@Shubham Bajaj So is the official answer here that there is no way to get DTMF to work within VAPI even with the SIP Truck? We are at a point where we just need to know if we need to call it here and move onto another platform.

@Edpreble You cannot play an audio file during the conversation this is only possible in the first message. Please let me know how I can help you further.