DTMF ISSUE - CASE 40241 - URGENT

[david_cc]

Hello,

Hopefully someone is able to help me with this.

I have contacted Yealink support and EVERY single time, they are replying back with "it is not clear". So maybe someone can help me clear this for Yealink support.

Here is my problem:

UserA (Yealink T19 E2) places a call to phone number 818-888-8888, the call is placed on hold, and a second is established to 818-999-9999. Using the "conference" button, a three-way call is then established. So this means that UserA, 818-888-8888 and 818-999-9999 are on the call. At this point, userA needs to press/send DTMF 1234. When 1234 is pressed using the Yealink phone, 818-888-8888 and 818-999-9999 are not receiving the DTMF. It seems that DTMF is completely ignored when there is a three-way call is established.

I have replicated this with T19 E2 and T21 E2... However, the above scenario works perfectly fine on T48G.

I compare the configuration on both T48 and T19 and they look the same to me. Is there a setting or something that can prevent us from sending DTMF while in a conference (three-way) call?

Yealink Support, please refer to case 40241. I have provided all the logs in there but unfortunately every single time I'm explaining the problem, you are coming back to me with "it is not clear".

Thanks.