Product Model: S-Series V4, S20&S50
Firmware Required: 65.16.0.X
The user might have echo issue when using analog line to make calls.
Previously, we recommended some commands to adjust the chip register value on for S-Series V4 to debug the echo issue. It is a bit complex to operate.
Recently, we optimize the commands and make the debug process automatic as well as the echo cancellation algorithm to improve the voice quality.
And we offer a specific firmware which includes this optimization. Here is the download link: https://update-ys2015-alicloud.oss-cn-hongkong.aliyuncs.com/YeastarSupport/image/22.214.171.124.bin
We advise the user to upgrade the firmware when he meets the echo issue.