topic Re: VOIP on three mobile home broadband in Tech Help - Software/Hardware etc

VOIP on three mobile home broadband

mystreet1 — Sat, 06 Sep 2025 20:33:12 GMT

Hi all,

Has anyone got VOIP working successfully on three mobile home broadband? Tried today and it appears that all setting are disabled on the router (rebadged HUAWEI B535). All it states is CLNAT is in use, this function has been disabled. Think that it may be due to three using IP6.

TIA

Re: VOIP on three mobile home broadband

MisterW — Sun, 07 Sep 2025 06:05:53 GMT

@mystreet1 If Three are using CGNAT then you won't be able to implement any port forwarding on the router. So configuring your voip device to use STUn and then port forwarding on the router won't work.

You should/might be able to get voip working by configuring your voip device to use 'NAT keep alive'

Re: VOIP on three mobile home broadband

markhawkin — Sun, 07 Sep 2025 08:08:11 GMT

It is likely that (leaving aside any network constraints) that the "3" custom firmware disbles this feature.

I would try a VoIP client on a phone connected to the router's WiFi.

If that works then there is hope of getting a router working with VoIP.

Then investigate alternative firmware for the router.

There is (or was) a "3" APN that wasn't CGNAT.

Re: VOIP on three mobile home broadband

dvorak — Mon, 08 Sep 2025 08:35:11 GMT

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