1,one channel GSM VoIP gateway 2,support ITU H.323 V4 and IETF ... 5,NAT traversal. Product Introduction:The GSM Fixed Wireless Terminal 1 ports Gateway GoIP-1 is a 1 SIM Card Broadband Phone Gateway that ... Power, Ready, Status, WAN, PC, GSMCall forward from GSM to VoIP and VoIP to GSMDial in mode or dial out mode onlyDial ... ,Now you are calling with your customer by server. 1 channel GSM VoIP gateway