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.
This is Helen Hu from China Skyline which in the field of VoIP products, GSM Modem, sim bank and wifi phone. And also deal in routes .Urgent need non cli 92 pak direct route who has voip gateway .