... GSM,CDMA,WCDMA VoIP gatewaty voip gsm gateway Key features:1.4 channels, 8 channels, 8 channels with 32 sim ... compression etc.), fully compatible with Asterisk and wellknown VoIP device providers(Cisco, Huawei etc.), for deploying flexibly many communication solutions, ... /900/1800/1900/2100MHzCall Control ProtocolsSIPVoice CodecsG.729A, G.723.1, G.711 a/ulawNetwork ProtocolsIPv4, TCP, UDP, PPPoE, DHCP, ...