we had one Call Manager that is connected to DX2030, this last is connected via E1 to DX2060 that is connected finally to provider.
the scheme is like this : Cisco Call Manager ——–> DX2030 ——–> DX2060 ———–> Provider
the problem is when i make call, i have in the trace of DX2060 prompted out in screen the message : “FullDuplex DSP allocation failed”, and the busy tone heared
This usually means you have exceeded the number of DSPs available for VoIP. You did not mention how many E1s are connected between the 2 DXs, but if you have 2,the DX2030 will only support 30 VoIP calls (even though it will have 60 E1 channels).