4. LSW-500: Product characteristic • Support SIP2.0 (RFC3261), TCP/UDP/IP, RTP/RTCP, HTTP, ICMP, ARP/RARP, DNS, DHCP, NTP, STUN, and TFTP etc; • Use the DSP CNOS chip to keep a wonderful audio-quality, advanced shaking control, and the technology of hiding the lost message; • Support kinds of voice coding, including G.711 (alaw and u-law) G.723.1 (5.3K/6.3K) G.726 (40K/32K/24K/16K), G.729A/B, and iLBC; • Support incoming call on show, restricting, and holding, disconnection, call transfer, call divert, DTMF, dialing project, etc; • Support conference call; • Support passing through and T38 fax, voice restrain and jerquers, CNG, echo restrains (G.168), AGC, and DIGEST using MD5 and MD5-sess; • Support layer 2(802.1Q VLAN, 802.1p) and layer 3 (QoS, DiffServ, ToS); • Support NAT auto- penetrating, no need to modify the setting of the NAT; • Support configuration files by inside IVR equipment, Web browser, HTTP Center Server; • Support upgrading encrypts configuration files by HTTP; • Microminiaturize and legerity design (size as a wallet), a voice gateway that convenient for schlepping