One RS232 port for configuration Two 10/100M Base-T connect WAN/LAN Four E1 ports, 75W/120W 1/2/4E1, provide 24/48/120 lines VoIP channel Supports VLAN TAG Supports on line software upgrade Supports multi configure, as Console, Web, Telnet and SNMP Supports T.30/ T.38 fax, fax translate Supports multi PSTN signal: China NO.1, 2M E&M, PRI and R2 Supports embed GK, performances address translate, GK verify, bandwidth management and neighbor GK etc. Max 128ms echo cancellation Auto-sensing dynamic buffer technology, Max 150ms, to meet bad network environment application Management User's level authority, high security Force reset factory setting, good survival Adopt authority/verify etc. network security, supports Caller verify and B-called limited Option input/output gain control Billing: Cooperate with Gk-billing-N system, Max store call list 16000 entries E1 Monitor: real time monitor each timeslot's calling status Relay grouping: E1 relay resources grouping User management: distinguish user according to number prefix Call stat; real time check call amount, success call rate etc. Protocol analysis: real time track protocol Modify as time slot and user caller ID Control Protocol: H.323, SIP Voice Codecs: G.711 (A-law and u-law), G.723.1, G.729, supports voice compress arithmetic dynamic switch Ethernet port: IEEE 802.3 10BASE-T Ethernet IEEE 802.3u 100BASE-TX Fast Ethernet Network Protocol: TCP/IP, UDP, ARP, ICMP, TELNET, SNMP, HTTP, RTP/RTCP, TFTP,NAT Network Management: SNMP Telnet Web-based GUI Console Security Feature: Password-Protected Administration on Telnet, Console, Web and SNMP Supports VLAN, avoid network storm