GoIP User Manualhttp://www.dbltek.com 41.2 Protocols TCP/IP V4 (IP V6 automatic adaptive) Dual VoIP protocols: ITU-T H.323 V4, IETF SIP V2.0 Multiple Codecs: ITU-T G.711 Alaw/ULaw, G.729A, G.729AB, G.723.1 and GSM H.2250 V4 H.245 V7 H.235 (MD5, HMAC-SHA1) RFC1889 real-time digital transmission protocol NAT STUN Network Management Protocol (NMP) PPPoE Dial Up PPP Authentication Protocol (PAP) Internet Control Message Protocol (ICMP) TFTP Hypertext Transfer Protocol (HTTP) Dynamic Host Configuration Protocol (DHCP) Domain Name System (DNS) User Account Authentication (via MD5) Proprietary Relay Protocol (Avoiding VoIP Blockings)1.3 Hardware Features ARM processor DSP for voice signal processing Two 10/100MB Ethernet ports (IEEE 802.3 standard) with status LEDs Quadband GSM module (850M 900M, 1800M and 1900M) External Antenna (Internal Antenna option for selected models)1.4 Software Features LINUX OS Built-in Web Server for device configuration Built-in SIP Proxy (Simplified) PPPoE Dial Up Router function DHCP client & Server QoS (VLAN) VPN (PPTP) Online firmware upgrade Remote Control Mechanism for remote technical support Proprietary Auto Provisioning Mechanism Remote SIM function Short Messages (SMS) support (standalone and server based)