You must connect the Ethernet WAN line, such as DSL and firewall, to the Ethernet WAN port. Use a CAT5 Ethernet cable to connect the WAN line to the port.

For G450 Branch Gateway v3, use Shielded Twisted Pair (STP) type CAT5e cables to connect to the jacks labeled "ETH WAN" or "ETH LAN" in the countries that require the EN55022/EN55032 compliance.