? Performance and features
    SIP v1 (RFC2543), v2(RFC3261)
    Support Route,Two 10/100Mbps MACs
    Support T.38(Doing)
    IP/TCP/UDP/RTP/RTCP
    IP/ICMP/ARP/RARP/SNTP
    TFTP Client/DHCP Client/ PPPoE Client
    Telnet/HTTP Server
    DNS Client
    NAT/DHCP Server
    Support G.723.1 5.3k/6.3k, G.729, G.711 A-Law, μ-Law audio codec algorithm
    Dynamic voice detection Echo cancellation Comfort noise generation
    Tone generation and Local DTMF generation and detection according with ITU-T
    Settings by HTTP web browser (IE6.0)
    Advanced settings by Telnet
    Voice prompt
    Upgrade by TFTP 
    2RJ45 Ports,Built-in Router,conference,Auto-provison or updating by HTTP,FTP or TFTP.
    For each YGW30A,it can have 3-SIP account,all can be used as caller at anytime.It can be selected among these 3-SIP account as caller by dial different dial prefix.It can be used as PSTN ordinary phone when power off.
    For each YGW30B,it can have 3-SIP account and one PSTN phone number,that means each ATA own 4 phone numbers,all can be used as callee at anytime.For the caller,these 4 account can be selected by dial different relevant prefix(including switch to PSTN as an ordinary PSTN phone)
    YGW30B has a real FXO port to support router call from PSTN to VOIP or from VOIP to PSTN.
? Main technical index
    Main chip: 32-bit RISC CPU with 125MHz clock rate
    Data storage:2MB SDRAM
    Program memory: 1MB Flash memory
    Application Network environment: Two 10/100Mbps Fast Ethernet MAC
    Echo cancellation:G165 16ms
    Store quick dial number: 100
    Record phone number of missed call:80
    Power loss:2.7W(max)
    Power adapter: input AC 220V,output DC 9V 500mA
    Employing condition:
    Ambience temperature 0-40℃(32-104°F)
    Relative humidity 10-95%
    Atmosphere pressure 86-106Kpa
    Overall size:113 x 80 x 28 mm (L x W x H)