Big audio issues with Yealink T23G

I have a fleet of Yealink T23G phones. Many people are reporting audio issues with them. They say that the audio cuts off briefly during a conversation. Especially if two people are talking over each other (similar to duplexing issues in the old days).

When doing an echo test (*43) and making a continuous sound, the sound is only played back to me in pieces. I.e. sound - small break - sound.

I think this is the problem. I am also trying from my T20P and I don’t have the issue there.
Yealink fimrware: T23-44.80.0.95

Drop back to T23-44.80.0.80 - lots of reports on Yealink forums (and I have also had problems) - .80 is the best for right now.

Just dropped back to 44.80.0.60.
Same issues.

Not .60 - .80 - we had TONS of problems with .60

On T23-44.80.0.80.
Same issues.
Not on my T20P, I will try on my T42G now.

Can anybody confirm having the same problem? Try an echo test, make a continuous sound, and see if it comes back on/off in pieces, not continuously.

Jesus, these phones are unusable like this. Hope I can figure this out.

I was experiencing this and believe it was solved when I changed the jitter buffer from Adaptive to Fixed.

After the change, I made a short phone call with the T22P and did not hear the dropouts. I did not test it on a long call.

Thanks for the tip.
I tried the jitter buffer but problem persists.

I went back and reviewed my settings. It was not the jitter buffer that made a (noticeable) difference. It is the VAD. I turned off VAD and also CNG (because I think the comfort noise is too loud anyway) and this got rid of most of the dropouts. I suspect the VAD is too sensitive.

To test, I tried the long continuous sound test in the *43 echo tester. With VAD and CNG turned on, I got the dropouts every few seconds. With it turned off, I didn’t hear any dropouts.

I also tested by dialing to a MOH source and listening to the music for a few minutes. In two minutes, I heard a single dropout, but I don’t know whether it was because of my phone or a common Internet issue (my PBX is hosted). Regardless, the audio is significantly improved.

VAD is BAD:

http://www.dialogtech.com/blog/general/why-does-my-voip-connection-sound-so-bad

Seriously, we ALWAYS turn it off because the lack of Comfort Noise (the noise floor in the background) makes people think the system is dropping audio - even when it is not.

Hi everyone.

I have the same problem as the OP on three Yealink T21P E2 (infact, i even posted on the same thread on the Yealink Forum, but we had no answer).

Simon pointed me to this thread.

I have ECHO cancellation, VAD and CNG turned off, and i also tried to switck the Jitter Buffer from adaptive to fixed, all with no results.

To be clear nothing is wrong if the two parties of the call don’t speak at the same time, as avayax reports.