... Mapping (Ethernet ports) Port Forwarding NAT Application Level Gateway for popular applications DHCP Server/Relay/client DNS Relay Agent ... serial interface or Telnet Diagnostic Test Firmware upgrade-able for future feature enhancement Supports Remote Access Control Security support ... LED Indicators PWR,LAN1,LAN2,LAN3,LAN4,VoIP1,VoIP2,WLAN,DSL,INET Environment Operating Temperature: 0°C~40°C Storage ...