Grandstream GXP2120 6-Line Executive HD IP Phone, VoIP Phone and Device Generous 320x160 pixel backlit graphical LCD display with up to 8 level grayscale 7 programmable hard keys and 4 XML programmable context-sensitive soft keys 6 lines indicators with individual SIP account profiles Multi-line support of up to 13 call appearance lines with dual-color LED indicators Support SIP (RFC3261), TCP/IP/UDP, RTP, HTTP, ARP, ICMP, DNS (A record and SRV), DHCP(both client and server), PPPoE, TFTP, NTP