S1003-GSV GSM Wireless Fixed VOIP Gateway is unique new product, insuring the GSM network and the VoIP network connecting seamlessly. Mobile phone SIM cards can be inserted within S1003-GSV, users of GSM phones can be registered to VoIP Softswitch system. Mobile users can be achieved through GSM network on the car alight. S1003-GSV built-in SIP, configuration flexibility. S1003-GSV is popular product by PBX vendors, system integrators and provider of choice