... )/TFTP (RFC1350)/DNS(RFC1034,RFC1035)SIP RFC3261, RFC3262, RFC3666, RFC2543 -IP (RFC0791), TCP (RFC0793), UDP (RFC0768), ARP (RFC0826)-ICMP, ARP, ... (RFC2069/ RFC 2617)-NAT traversal: STUN, NAT ALG, NAPT, SIP Express router-2 RJ-45 auto-sensing 10/100Mbps, with Router ... ports support FSK and DTMF Caller ID)2.6 Advanced IP-PBX FeaturesSupports Automatic Call Distribution- Random, Rotation, Longest Idle, ...