If you are experiencing voice issues while running AOS R13.8 or R13.9, ADTRAN recommends the following:
If you don't require a feature that was included in the AOS R13.8 or R13.9 firmware release, ADTRAN recommends using AOS firmware version R13.7.2 for the most stable
experience currently available.
If you require a feature that was included in the AOS R13.8 or R13.9 firmware release, ADTRAN recommends using the newly released AOS R13.9.0 HB firmware.
