SingTel Fibre : RT-N15U
Most newer ASUS routers have in-built ISP specific vlans setting like the UniFi, Maxis, SingTel, M1, etc.
The RT-N15U is another nice looking black-diamond device to consider, I tested it with the latest beta ASUSWRT firmware on SingTel Fibre without any problem !
Apart those setup & stuff which I've posted previously, for SingTel only need to change the following.
Before proceeding, DO NOT connect the device's WAN to the GPON/ONT/BTU !!
This is because SingTel Fibre does check & verify on the router's MAC address ....
Ensure you already copy down the SingTel's original router's MAC address (refer HERE on how to get the MAC address)
Go to LAN --> IPTV, select the SingTel-Mio profile, click Apply when done
Go to WAN setup, setup as follows, click Apply when done
Remember to enter the MAC address correctly as per the original SingTel's router.
Once done, connect the device as follows:
WAN --> SingTel Fibre GPON/ONT/BTU port1
LAN1~2 --> use for internet
LAN3 --> SingTel's original router's WAN port (Pace or 2Wire) --> RJ11 port --> Phone
LAN4 --> Mio-TV box