TP-Link T1600G-18TS Configuration Manual page 213

Configuring Protocol VLAN
2) Click Create to load the following page. Create VLAN 20, and add ports 1/0/2-3 as
untagged ports to VLAN 20. Click Apply.
Figure 3-3 Create VLAN 20
3) Click Save Config to save the settings.
Configuration Example
Configuration Guide 190