a voip gsm gateway enables direct routing between ip and gsm network without the use of a fxo port or the pstn network. with this device, the usage of voip is greatly enhanced with significant savings on long distance and roaming charges.

øtcp/ip v4 (ip v6 auto adapt)

øitu-t h.323 v4 standard

øh.2250 v4 standard

øh.245 v7 standard

øh.235 standard（md5，hmac-sha1）

øitu-t g.711 alaw/ulaw, g.729a, g.729ab, and g.723.1 voice codec

ørfc1889 real time data transmission

øproprietary firewall-pass-through technology

øsip v2.0 standard

øsimple traversal of udp over nat (stun)

øweb-base management

øppp over ethernet (pppoe)

øppp authentication protocol (pap)

øinternet control message protocol (icmp)

øtftp client

øhyper text transfer protocol (http)

ødynamic host configuration protocol (dhcp)

ødomain name system (dns)

øuser account authentication using md5

øout-band dtmf relay: rfc 2833 and sip info