AddPac AP-GS1004A is one of the models of inter-network VoIP GSM gateways, through which, it is possible to format a single network unit and to use it for VoIP-telephony, analog communication lines and GSM-network.
Citel Technologies , A Voice over IP Phone company that provides VoIP Business Phone Systems. Its Main products include EXTender, PBXgateway, Upgraded Hardware Products, PBX platforms etc.