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.
MaxiTEL Telecom provides high quality connections for businesses and also focuses on serving resellers. MaxiTEL provides an overall concept of telecom: VoIP, mobile data and voice, SMS, fax, DSL, Fiber.