By using Portech SBK-32 expander for 32 SIM-cards, you can increase the number of channels in the Portech MV-37X GSM VoIP gateway series using the Internet.
Inter2fone has it Headquarters in Miami, FL USA and has regional offices in Equator (Southamerica), and Switzerland (Europe). Was inittialy formed like a division of FIX GROUP to attend VoIP services for the Latinamerican Market.