After upgrade 3CX from V18 to V20, User call External hear only 1 ringback tone, then silence.
The call can be establish if external pick it up. But is hard determine if the call is drop already or not until it say fail.
Internal call ringback tone is normal.
We have using Patton Trinity ISDN T1 (SN4171/SN4970A) for gateway, not sure if it 3CX V20 not support and how to fix.
The call can be establish if external pick it up. But is hard determine if the call is drop already or not until it say fail.
Internal call ringback tone is normal.
We have using Patton Trinity ISDN T1 (SN4171/SN4970A) for gateway, not sure if it 3CX V20 not support and how to fix.
