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.
IPVFone is a new type of phone service which gives you a choice of a "Monthly Plan" or "Pay as you go" phone service. Make unlimited calls to the US and Canada or other countries using one of our incredible unlimited plans.