... RFCs; 2)Can connect to SIP1 and SIP2 server at the same time; 3)Support SIP domain ... SIP authentication (none, basic, MD5), DNS name of server, Peer to Peer/ IP call·SIP support 2 SIP ... for ADSL·Support DHCP Client on WAN·Support DHCP Server on LAN·Support VLAN (optional: voice vlan/data ... Support VPN (L2TP)·Support main DNS and secondary DNS server·Support DNS Relay, SNTP Client, Firewall·Network tools ...