@YanAndrew 

Have you ever tried to connect Maxis router behind the main Deco, then check whether the VOIP registration could still work on Maxis?

(You could also turn on UPNP on the Deco APP to see if it helped.)

best regards and wait for your reply.

Hello @David-TP, yes I have and the VOIP works that way. UPnP has always been enabled.

However , the problem with that connection is that the main mesh router would be in Access Point mode, wouldn't it? That would mean I would lose quite a number of features of the Deco M5 which is not what I want. I decided on the Deco M5 for those features.

So far, I can only find a tutorial on replacing the Maxis Fibre router with a third-party non-mesh router to get VOIP, but not one with a mesh router, which really bugs!

I'm hoping someone can help me with this issue.

  @YanAndrew 

Thank you very much for your kind update

What I suggested is like the following layout:

Fibre service---TM Unifi home fibre modem--<Ethernet>-Deco M5-<Ethernet>---Maxis Wi-Fi 6 router with VOIP

then enable "SIP ALG " and "UPNP"on Deco M5.

I could not guarantee it could work 100% but you could have a try on the Maxis router to see whether the VOIP service is still able to communicate with the VOIP server.

(I see it once from another user and he did not feedback anymore.)

There is another suggestion and you could have a look: OneMesh networks, such as Archer VR2100V+ RE650/RE300

https://www.tp-link.com/en/onemesh/

Hi @David-TP,

Thank you for your suggestion. I've just given it a try and unfortunately, it does not work. The VOIP still does not work.

Looks like there is no straightforward solution to my issue. I think my last resort is to go to Maxis and urge them to either device a usable solution and/or communicate with TP-Link to achieve that.

I appreciate your help though.

  @YanAndrew 

Hi, I got some feedback from users that Deco X73-DSL seems ready for sale in AU and it supports VOIP feature.

maybe you could have a look:

https://www.tp-link.com/au/search/?q=Deco+X73-DSL&t=product&category=home

Best regards.

  @David-TP unfortunately, that is not a solution for me. I paid RM600+ for my 3-pack mesh network not long ago and I chose the Deco M5 for its features. I'm not looking to buy another set in a hurry.

Thank you for highlighting it though.