ZyXEL Prestige 660H-D3 ADSL2+ 4-port Gateway over ISDN/U-R2. DSL connection type: ADSL. Networking standards: IEEE 802.1D. Routing protocols: RIP-1, RIP-2, IGMPv2, IGMP, Management protocols: SNMP, Telnet, HTTP, Supported network protocols: TCP/IP, PPTP, UDP/IP, L2TP, ICMP/IP, IPSec, PPPoE, PPPoA. Certification: CE, FCC. Operating temperature range (T-T): 0 - 50 °C