1)support sip 2.0 terminal product, powerful applicability, and best for global popularizing; 2)support sip 2.0, tcp/udp/ip, rtp/rtcp, icmp, arp/rarp, ntp, pppoe, tftp, http, etc; 3)support g.711 (alaw and u-law), g.723.1 (5.3k/6.3k), g.723 (40k/32k/24k/16k), g.728, g.729a/b, ilbc; 4)the powerful dsp digital audio processor to keeping a wonderful audio-quality; 5)advanced shaking control, and the technology of hiding the lost massage 6)support incoming call on show, restricting, and holding, disconnection, call transfer, call divert, dialing project, etc. support conference call; 7)supports vad, cng, agc, the echo eliminates (g.168) and the static sound suppression; 8)support layer 2 (802.1q vlan, 802.1p) and layer 3 (qos,, tos diffser