Voice delay Yealink vs Grandstream

[patbouch]

Hi,

4 phones on the same Ethernet switch in laboratories with asterisk server.

1 x T23G
1 x T27P
1 x T21P E2
and 1 x Grandstream DP715

During a conference call between master phone (T23G), slave (mute enable, T27P) and slave (mute enable, Granstream DP715), i hear easily a delay of about 100 ms between the two slaves.

I say "check", I hear in the grandstream, and after in the Yealink.

I tried with the T21P E2, same result. (100ms after, time to say "check").

But T21P E2 and T27P, in slaves, they receive at the same time.

Conclusion : The grandstream DP715 restores faster the sound.

I reduce the Jitter Buffer (20/80/40) without success.

Does the processor/firmware is slow to return the song ? I personally think it's a problem on the firmware performance.

Knowing that every millisecond is important... This is not good...

Last firmware : TXX-44.80.0.95

Do you have an idea of the problem?

Patrick Bouchard