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.
SpeedVoIP, Inc. is a leading designer and manufacturer of innovative and cost-effective VoIP telephony products, and becomes a major OEM vendor of VoIP terminal products and solutions in the rapidly growing global IP telephony market.