Customer account of Aastra 57i Echo:
"I am able to reliably reproduce the Aastra 57ic cordless handset echo issue. When I am on the Aastra cordless phone, the person I am talking to hears themselves echo. I am able to make the echo come and go at will by adjusting the volume on the cordless set (there is a little volume control on the side of the cordless handset). Once I raised the volume above about half way, the person I was talking to reported hearing themselves echo. Turn the volume down and the echo went away."
We do not have a 57i in-house to test, so all we can go on is the above customer testimony. Our take on the above is that the Aastra cordless has echo cancellation problems and the receiver audio is bleeding into the transmitter and not getting canceled. This is something that would be fixed by Aastra in future hardware/software releases.
See our top business VoIP phone recommendations for 2017