Qoffee 0.7 with DTMF do not work

[prasaddp5]

I am able trying to send DTMF value("1") using the recommended function insertDTMF(tone), however I see the following logs, however DTMF digits are not really recognized by the Mediaserver, any pointers to make it work?

RTCDTMFToneChangeEvent {tone: "1", clipboardData: undefined, cancelBubble: false, returnValue: true, srcElement: RTCDTMFSender…} qoffeesip.js:184 [INFO] DTMF send - 1 qoffeesip.js:185 RTCDTMFToneChangeEvent {tone: "", clipboardData: undefined, cancelBubble: false, returnValue: true, srcElement: RTCDTMFSender…} qoffeesip.js:184 [INFO] DTMF send - qoffeesip.js:185 RTCDTMFToneChangeEvent {tone: "1", clipboardData: undefined, cancelBubble: false, returnValue: true, srcElement: RTCDTMFSender…} qoffeesip.js:184 [INFO] DTMF send - 1 qoffeesip.js:185 RTCDTMFToneChangeEvent {tone: "", clipboardData: undefined, cancelBubble: false, returnValue: true, srcElement: RTCDTMFSender…} qoffeesip.js:184 [INFO] DTMF send - qoffeesip.js:185

Thanks, Prasad

[damianfral]

Hi again @prasaddp5,

Logs show DTMFs are being sent. The problem may be your server doesn't recognize RTP Events (WebRTC sends DTMFs as RTP Events, not as in-band audio). We have tested DTMFs with a WebRTC-PSTN gateway and I could heard the tones.

[prasaddp5]

Thanks for the information, it looks like a drawback in webrtc not to have support for in-band DTMF signalling and nothing specific only to Qoffee.

[prasaddp5]

Hi Damian, Quick question, should'nt Qoffee send INFO with the DTMF Event, I do not see INFO sent from Qoffee.

Thanks, Prasad

[damianfral]

Hi @prasaddp5,

We could send DTMFs these ways:

1. SIP INFO
2. RTP audio
3. RTPC event

We chose option 3, because WebRTC API supports this. This means signalling is not aware of DTMFs and DTMFs are not directly audible because they are not in the audio, but a server could read these events and insert them as tones in the audio (in order to get DTMFs wotking through PSTN).

We haven't plans to implement option 1 or 2. You can do it by yourself. Option 1 is just working with a new king of SIP message. Option 2 may be the harder one, in fact, I'm not sure it is possible. You could try to use WebAudio API to "inject" tones in the local audio object.

By the way, what server are you using?

[prasaddp5]

Thanks, I am using Dialogic and a Radisys media server. Not sure if any of these can support RTPC events?

Which server did you test DTMF with?

-Padma Prasad

[prasaddp5]

I am using wertc2sip as the Mediaproxy to connect to external media server(Dialogic) for announcments.

[damianfral]

We tested it with a third party SBC. I'll test it again with FreeSwitch.

[prasaddp5]

If I understand correctly in your setup, Javascript( Webrtc client) used to send DTMF as Event based signaling to SBC. And SBC used to convert it to either Inband or INFO based DTMF and send it to mediaserver?

[damianfral]

Event based signaling

No. RTP events travel in the media plane but out of band (see RFC 2833). SBC translates DTMFs to inband tones (in order to work in analog lines). I guess SBC can be configured to translate them to SIP INFO messages. @antonroman could give you a better answer. :smile:

[prasaddp5]

I will try to test dtmf with Freeswitch got it installed in my labs, were you able to test qoffee dtmf with freeswitch.