Rooster_au
Level 2: Rookie

Using Telstra Smart Modem for 4G backup only

I am on HFC NBN. I would like to use my own router as the Telstra Smart Modem Gen 2 is feature limited, while its 4G backup is very helpful. An ideal solution for me is to get a dual-WAN router setup in failover mode, with the primary WAN connected to the NBN modem and the secondary WAN connected to the Telstra Smart Modem LAN port. Nothing is connected to the WAN port on the Telstra Smart Modem. In this way, when NBN is up, all traffic goes through NBN. When NBN is down, a basic connection is provided through the Telstra Smart Modem 4G. With this configuration, 4G is alwasys connected to the Telstra Smart Modem although there is no data traffic when NBN is up. Would this cause any problem with Telstra?

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3 REPLIES 3
Jupiter
Level 25: The Singularity
Level 25: The Singularity

Re: Using Telstra Smart Modem for 4G backup only

It probably will cause an issue in that Telstra will see that the 4G backup is in continual operation and you will be notified that you need to switch back to your NBN connection. If you didn't follow up on it, the 4G backup would eventually be disabled to to abuse of service.

 

There are 2 methods to avoid this.

Plug the Telstra modem into the NBN NTD and then connect the WAN port of the new router to a LAN port of the Telstra modem.

or, Plug the new modem into the NBN NTD and then plug the Telstra modem WAN port into a LAN port of the new router and set the Telstra modem in the DMZ of the new router.

Never be afraid to back yourself when trying new things, just always make sure you have 3 escape routes if things go wrong.
Rooster_au
Level 2: Rookie

Re: Using Telstra Smart Modem for 4G backup only

The 2 options would create a double-NAT problem where the 2nd router would not see the external IP. How about taking the SIM out from the Telstra Smart Modem and put it in another 4G modem as input for the dual-WAN router secondary WAN? Would this be detectable by Telstra and lead to disabling of the 4G service?

 


@Jupiter wrote:

It probably will cause an issue in that Telstra will see that the 4G backup is in continual operation and you will be notified that you need to switch back to your NBN connection. If you didn't follow up on it, the 4G backup would eventually be disabled to to abuse of service.

 

There are 2 methods to avoid this.

Plug the Telstra modem into the NBN NTD and then connect the WAN port of the new router to a LAN port of the Telstra modem.

or, Plug the new modem into the NBN NTD and then plug the Telstra modem WAN port into a LAN port of the new router and set the Telstra modem in the DMZ of the new router.


 

Jupiter
Level 25: The Singularity
Level 25: The Singularity

Re: Using Telstra Smart Modem for 4G backup only

I don't believe that the SIM from the Telstra modem can be used in anything but a Telstra Smart Modem. Even if it could be, it doesn't solve the problem as the 4G connection would still be active all the time.

Never be afraid to back yourself when trying new things, just always make sure you have 3 escape routes if things go wrong.

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