Best setup for international calls

[emerbrito]

Hi folks,

I'm trying to setup a system where i'll have one local number in Brazil to server our office there and here (USA).

Here is the scenario:

- 3CX PBX Software is installed on a dedicated server (Datacenter on Texas)
- The line it has is a VoIP lines provided buy an American company
- Since the number (in the VoIP line) is an New Jersey/USA number and we needed a number from Brazil, we got a virtual number (brazilian number) routed to this VoIP line
- Our offices are in New Jersey/USA and in Brazil

- Some results

. From extension to extension (Brazil x USA) using softphone, the quality is great.
. From a USA extension (soft phone) to any number in Brazil (PSTN line) it works very well

. if somebody in brazil (PSTN line) calls the virtual number (which is routed to the VoIP line) he/she will get the Digital Secretary. If the call is transfered to my extension in US, the quality is still good but...

HERE IS THE PROBLEM:
If this call is transfered to an extension in Brazil, the quality is terrible:
the sound is choppy and cutting off.

Anyone has an ideia to help on this?