Check The Installation - TRENDnet TW100-S4W1CA User Manual

LAN ports. Since the Broadband Router has four ports, you can
connect up to four computers directly to the unit. You do not have
to buy a switch to connect these computers since the Internet
Broadband Router functions as both an Internet connection-sharing
unit and as a switch.

Check the installation

The LEDs of the Internet Broadband Router are clearly visible and the
status of the network link can be seen immediately:
1. Once the device is connected to the broadband modem and the
Power is connected, the Power, LAN, and WAN port link LEDs of the
4-Port Broadband Router will light up.
2. If the WAN port is linked to the ADSL/Cable modem, the WAN port's
Link/ACT LED will light up.
3. If the LAN port is linked to the computer system, the LAN port's
Link/ACT LED will light up.