Grandstream GXP-1200 2 Lines Business Phone SIP 2.0, TCP/IP/UDP, RTP/RTCP, HTTP/HTTPS, ARP/RARP, ICMP, DNS (A record and SRV), DHCP (both client and server), PPPoE, TFTP, NTP, Telnet Dual switched 10/100Mbps Ethernet ports w/integrated Power-over-Ethernet (802.3af) 8 dedicated buttons - hold, speakerphone, send, transfer, conference, headset, mute, messages Full duplex speakerphone w/advanced audio echo cancellation 8 dedicated buttons - hold, speakerphone, send, transfer, conference, headset, mute, messages