No internet HT812 weirdness



Hoping someone can point me in the right direction. Very strange use case, HT812 on a self-contained no internet network. I have FreePBX running perfectly. HT812 registers and works perfectly when I have the WAN connected to internet. Disconnect internet? Immediately starts acting weird.

HT812 to Softphone:
Call immediately gets placed on hold???

Softphone to HT812:

HT812 to Virtual Voicemail Extension:
No audio, despite Asterisk playing it.

Softphone to virtual voicemail extension works perfect as well, even without internet.

I’ve been in VoIP for many, many years, and I’ve never seen anything like this.


What are you using for DNS ? and have you disabled Firmware / GDMS cloud within it ?


There is no DNS running accessible to it. There shouldn’t need to be, but, I’m sure that’s the cause.


Well consider the following DNS entry… maybe it will work maybe not - try

#5 seems to work! (or it was something else)

Statically configured WAN IP
Disabled every kind of network connectivity check
Disabled upgrade checks
Disabled 3CX Auto Provision

and probably numerous other things. It still reports the lines are unregistered, but, they work, and that’s all that matters.

Thank you so much for the help!