The Yeastar TG400 4Port GSM-Gateway has the following features: • Has Four (4) GSM/CDMA/UMTS Channel. • GSM Frequency: 850/900/1800/1900 MHz. • UMTS Frequency : 850/1900 MHz, 850/2100 MHz, 900/2100 MHz. • CDMA Frequency: 800 MHz. • Protocol: SIP, IAX2. • Transport: UDP, TCP, TLS, SRTP. • Voice Codec: G.711 (alaw/ulaw), G.722, G.726, G.729A, GSM, ADPCM, Speex. • Echo Cancellation: ITU-T G.168 LEC. • DTMF Mode: RFC2833, SIP INFO, In-band. • Calling Type: Termination (VoIP to GSM/CDMA/UMTS), Origination (GSM/CDMA/UMTS to VoIP). • LAN: 1 x 10/100Base-T Ethernet. • Network Protocol: FTP, TFTP, HTTP, HTTPS, SSH. • NAT Traversal: Static NAT, STUN. • Network: DHCP, DDNS, Firewall, OpenVPN, Static IP, QoS, Static Route, VLAN. • Power Supply: AC 100-240V. • Operation Range: 0°C to 40°C, 32°F to 104°F. • Storage Range: -20°C to 65°C, -4°F to 149°F. • Humidity: 10-90% non-condensing.