SIMADO GFX44 is a fixed configuration GSM/3G-FXS voice gateway. It connects with the existing telephony devices via FXS interface. Up to 4 SIM cards can be placed inside the SIMADO GFX44 gateway allowing up to 4 concurrent calls. The calls to mobile numbers are placed via the GSM/3G SIM cards, reducing higher fixed-to-mobile interconnection charges. The gateway serves as an ideal solution for business organizations.