Specification
Number of Telephony Ports: 4
Phone Interface: 4 x RJ11 FXS ports
Protocol: SIP (RFC3261), IAX2
Transport Protocol: UDP, TCP, TLS, SRTP
DTMF: RFC2833, SIP INFO, In-band
Codec: G.711 a/u-law, G.722, G.726, G.729a, GSM,
ADPCM, Speex
Echo Cancellation: ITU-T G.168 LEC
FAX over IP: T.38 and pass-through

Signaling: Kewl Start, Loop Start
Caller ID: BELL202, ETSI (V23), NTT (V23-Japan), and
DTMF-based CID
Disconnect Method: Busy Tone, Polarity Reversal

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

Size: 200 (L) mm × 137 (W) mm × 25.6 (H) mm
Power Supply:12V 1.5A

Operation Range: 0° to 40°C, 32° to 104° F
Storage Range: -20° to 65°C, -4° to 149° F
Humidity: 10-90% non-condensing

Features
-way Conference
Attended Transfer
Black List
Blind Transfer
Call Detail Record (CDR)
Caller ID Display or Block
Call Forward: No Answer, Busy, All
Call Waiting
Call Status Display
Do Not Disturb
IP Blacklist
Network Attack Alert
Paging
RADIUS Accounting & Login
Real Open API Protocol (Based on Asterisk)
Voice Prompt
SIP Server and SIP Trunk supported
SIP Peer Mode supported
SNMP*
TR-069*
System Logs
Web based configuration