... enabling voice communications. It is installed on the Mobile SIM Card, you can register the GSM telephone on the VoIP Softswitch ... , 8, 16 ports GSM VoIP Gateway. there are 7 models.GoIP-1 ( supporting one SIM card ), GoIP-1i ( supporting 1SIM card, built-in antenna ... customers is our greatest desire.9,What is our main express shipment?DHL,UPS,FEDEX,TNT,EMS(can ship to anywhere ...