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.
MCK communication is a part of Citel technologies, The VoIP Migration Company. MCK products like EXTenders, Gateways, and DTI call center solutions, are now available through Citel.