Specification
Number of GSM Channels (Max): 16
Antenna Splitter: 4 in 1
Network Type: 850/900/1800/1900MHz 
Protocol: SIP (RFC3261), IAX2
Transport Protocol: UDP, TCP, TLS, SRTP
DTMF: RFC2833, SIP INFO, In-band
Code: G.711 a/u-law, G.722, G.726, G.729a, GSM,
ADPCM, Speex
Echo Cancellation: ITU-T G.168 LEC

LAN: 1 (10/100Mbps)
Network: Static IP, DHCP Client, Firewall, VLAN, DDNS, 
QoS, OpenVPN
NAT Traversal: Static NAT, STUN

Size: 440x280x44 mm
Power Supply: AC 100-240V 50/60Hz

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