Googling around on the interwebs on the topic of setting up a custom router (non-maxis issued) with the Maxis Fiber service yields several guides that are outdated, inaccurate, in a long forum support thread format or lacking on all the key details. This post is supposed to address that problem

Long story short, I managed to get Maxis Fiber working with my custom router with VoIP after getting some help from a friend at Maxis (Thank you!).

One key point to note if you intend to use your own router:

Virtual Lan (VLAN) tagging support is a requirement for this to work.

Here I used the Asus RT-AC66U router running the Tomato firmware (v1.28.0510.6 MIPSR2Toastman-RT-AC K26AC USB VPN) for the Maxis Fiber (FTTH) service in a TM/Unifi (HSBB) area.

Below are the bare essentials:

VLAN VIDs needed: 621 for internet (PPPoE), 821 and 822 for VoIP/SIP to work.

The details: Here’s how it connects physically, the ethernet connection out of LAN2 (standard for UniFi/HSBB configured networks) from the optical network termination, (ONT), aka fiber modem, eg. Huawei EchoLife HG8240w; connects to the WAN port of the custom router. The custom router handles the internet connecting via PPPoE using the Maxis provided username and password.

Optionaly, should you want to use the VoIP service Maxis provides, tagging traffic on a LAN port (of your choosing) and the WAN port on your router with vlan id 821, 822. This allows the VoIP traffic to pass between LAN port and the WAN port, and no where else.

I used the Maxis issued Technicolor TG784nv3 router to handle the VoIP connection. The router’s WAN is plugged into the LAN port that has tagging set up. No additional configuration is needed in the Technicolor router, as VoIP has configured by the service installation technicians.

Advanced VLAN setting in tomato's webUI

Notes: In this version of tomato, the ethernet ports on the VLAN page is numbered in reverse in firmware from the physical markings on the router. (eg. plugged physical ethernet cable into LAN4 port on the router, configure for the LAN1 port on the VLAN page as in image above).

EDIT (July 2017): recieved email on the post with questions on the set up. Hence, the voip section was revised for clarity and simplification.