TPG Community

Get online support

Voip Settings for VDSL

Level 2

Has anyone tried connecting a switch to the nbn box and connecting it to WAN ports on your own router and the tpg router? The idea is that both routers work as independent modems and have a direct connection to the NBN.


That setup apparently works with Optus VoIP, whereas other setups like connecting one router to the other do not. You'd have to set a static IP on the TPG router, turn off the DHCP and point the Gateway to the other router.

Level 2

I've got a HFC NBN connection and the following setup lets me use both my BYO router as well as the VoIP phone.


I've put in a network switch (cost under $20) between the NBN Box and the routers. The NBN Box is connected to the switch. The switch is connected to the WAN port of the BYO router, and the switch is connected to the WAN port of the TPG router.


I haven't changed any settings in either router. They both have their normal IP addresses and both are running DHCP.


The effect is that you're running two independent LANs. The BYO router runs my main network and my WiFi. The TPG modem runs the phone connection. I've switched off the WiFi on the TPG modem as I don't need another WiFi network in the house, but that is a personal choice. In fact, if you put the TPG modem in a different part of the house another WiFi network may be useful. You can connect other devices to the TPG router to access the internet as well as each other, but they won't be able to communicate with the devices connected to the LAN on the BYO router.


Hope this helps.

Level 3
Level 3

Hi @marius,


The only way I can see this working is if TPG supplies 2 public IP addresses, one to each router respectively.  If that's the case, then awesome - this is a great solution, and avoids the double NAT issues that will plague users who are trying to publish services from their premises, etc.


Can anyone else confirm if they have had success using this method?

Level 2



The setup with a switch in front of 2 independent routers worked for me. I didn't have any extra public IP addresses or organise any special setup with TPG. Both routers had an internet connection, and the TPG router had a phone connection. I didn't run any other services.


However after a while I changed the setup. (I moved the TPG router to a location away from the NBN box  to use more of the existing ethernet wiring in the house for the main network, rather than run another cable).


The current setup is as follows:

NBN box to WAN port of Netgear Router

Netgear Router LAN port to WAN port of TPG Router

Phone connected to TPG Router

Both routers have internet connections and indepenent networks.

I use the Netgear Router for the main network.

(I put a switch in between the Netgear and TPG Routers to connect more things to the main network and minimise the cable run for the TPG network, but that's a personal preference due to the locations of the existing ethernet sockets in the house).



Level 3
Level 3

Wow, that's even more confusing, as everyone seems to say that unless the TPG-supplied router is connected directly to the NBN modem, VOIP services will NOT work.  You are describing a double-NAT setup with a working VOIP service.


I will be getting my TPG equipment delivered tomorrow so I will definitely be having a play.

Level 3
Level 3

I can confirm this setup works for TPG.  I have my own router and TPG's TP-Link router both connected to the NBN modem via a standard 5 port gigabit switch and TPG.  Both connect using PPPoE and TPG give each router its own public IP address.  I use the TP-Link router solely for VOIP (which works perfectly) and my own router for everything else.  Thanks for the tip @marius!



Level 2


I am investigating options in order to sign up to NBN on the HFC cable available in our area.

The setup you describe is exactly as I prefer in terms of my system configuration.

That Is -

NBN ARRIS connection box WAN port UNI-D1 to WAN port of my existing Netgear Router (Subnet nnn.nnn.0.1)

Netgear Router LAN port to WAN port of TPG Router (Subnet nnn.nnn.1.1)

Phone connected to TPG Router

I also require both routers to have internet connections and indepenent networks via one public IP address.

I also intend to use the Netgear Router for my main network.

Please would you let me know if the system set up that you describe is still working succesfully. I have asked the question of TPG but the my query remains unanswered.



Thanks for reaching out. You have the option to use your 3rd party modem/router as a main modem as long as it is a VDSL modem. The only way to get your 3rd party modem/router a WAN IP address if you have a block of IP address and it will be configured in the network or if you bridge our modem/router however, the VoIP service will not work as it encrypted to our supplied modem/router. 

You also have the option to use our supplied as the main modem/router to utlise the VoIP service and connect the 3rd party. We have an existing thread related to this, you may visit this link


Level 2

Third party devices work fine if you can aquire the SIP password. The only thing special about the firmware is that it blocks you from the SIP settings.

Level 2

you use a fritz box how do you get it to work with TPG I have not been able to so far FTTC fritzbox 7590 error TPG not acepting PPPoE packets