This is a VoIP GSM Gateway for call termination (VoIP to GSM ) and origination (GSM to VoIP). Supports Asterisk, SIP Proxy Server, VoipBuster. Specs: Protocols：SIP (RFC2543，RFC3261) TCP/IP：IP/TCP/UDP/RTP/RTCP/、CMP/ARP/RARP/SNTP、DHCP/DNS Client、IEEE802.1P/Q、ToS/DiffServ、NAT Traversal、STUN、uPnP、IP Assignment、Static IP、DHCP、PPPoE Codec：G.711 u-Law、G.711 a-Law、G.723.1 (5.3k)、G.723.1 (6.3k)、G.729A、G.729A/B Voice Quality、VAD、CNG、AEC、LEC、Packet loss[...]

a 2 channel VoIP GSM Gateway for call termination (VoIP to GSM ) and origination (GSM to VoIP). It is SIP based and compatible with Asterisk. It can make 2 calls simultaneously from IP phones to GSM networks and GSM network to IP phone. Tri band:900/1800/1900MHZ.[...]