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.
Antratel brought to life a new technology - access to VOIP EXCHANGE. Now, Antratel customers have access to VOIP EXCHANGE and can choose personally right price and quality for calls termination from thousands offers of telecom companies!