Firstly, after done with OpenWRT reflashing, backup your current setting of OpenWRT box.
Assuming you already performed the firmware upgrade.

The following will assist you to configure it to be usable with TM Unifi broadband.

Get to Network -> Switch.

Add the following VLAN.

1. 500 with setting “Port 1” and “CPU” as “tagged” , the rest “off”
2. 600 with setting “Port 1” as “tagged” and “Port 5” as “untagged”, the rest “off”

“Port 1” seem to be the “WAN port” to the another fibre device.
“CPU” is the inside-the-box interface.
while “Port 5” actually or physically labelled as the “LAN 4”

So, the overall physical connection from this box would be as follows..

“WAN” -> “TM Fibre Home Gateway ~ HG555a ~ Port 1”
“LAN 4” -> “TM IPTV Box ~ Lan Port”

“LAN 1 ” -> “Other LAN device” (mine goes to a ADAM device for development)
“LAN 2 ” -> “Other LAN device” (mine goes to another room’s network switch)
“LAN 3” -> “Unused”

Then for the Interfaces : need to setup PPPoE dialer to VLAN device (VLAN.500)

PPPOE Physical pointed to the (VLAN.500) ones.

PPPOE Firewall setting pointed to dedicated one for NAT.

That’s for the PPPoE , you should be able to connect by then.

For the IPTV, setting would as follows ..
It need to be VLAN.600 , and from the IPTV box,connection via “LAN 4”.

Interface : “Unmanaged”

Physical : VLAN.600

Firewall : Dedicated one for IPTV.

Well.. you may add your wireless devices and any other interface as you like.

Once, above is setup, you shall be able to see “Status -> Overview” which will report the current status of WAN/LAN.

you may also view the realtime graph (every 3sec update).

and ..that’s it for Unifi Setting.

You can also mingle with all other setting once above is done.

Such as adding more software to it..

Imposing QOS..

Multiple Wifi