Solved Yealink T38G won't provision

[CommsGuy]

Hello,

I'm about to switch an office to 3CX and am hoping to reuse their existing phones.
They're listed on the 3CX page listing supported phones as end of life, but my understanding is that they should still work. They're Yealink T38G phones.
The setup:
I have 3CX running on a google VM set up per this 3CX doc: https://www.3cx.com/docs/hosted-pbx-google-cloud/
I have a raspberry pi set up as an SBC.
I have installed the firmware given by 3CX on the phone - it's 38.70.0.228 and obtained from here: https://www.3cx.com/support/phone-firmwares/
Firewall check passes and I can make calls from the 3CX app on iPhone without issue.

SBC as far as I can tell is working fine. When I connect a phone it appears in 3CX under phones in bold as described here: https://www.3cx.com/sip-phones/yealink-t32g-t38g-t42g-t46g/
Under the IP field it lists the phones IP address via SBC, so the SBC seems to be doing its thing.

I can't get past here.
I have added the provisioning URL to the phone manually and selected autoprovision now.
I have ensured that "only accept trusted certificates" is disabled.
Is there something I missed in the limitations with end of life devices?
For this phone 3CX lists:

• No support for CTI via uaCSTA
• No direct UI login
• No support for “Let’s encrypt”
  (certificate check needs to be disabled manually if used as remote extension)

• No RPS Support
• In STUN provisioning assign a minimum of 12 RTP ports
• Incompatible with secure "SSL Transport and Ciphers" setting

Thanks for any input!

 

[cobaltit]

Did you turn off the PCI compliance SSL setting? Necessary for this:

Incompatible with secure "SSL Transport and Ciphers" setting

 

[CommsGuy]

I did on the firewall at the remote location and it made no difference.
Does something need to be done to 3CX (the Google VM) as well for it?
If so, do you know what? I have been unable to find anything on that front about the Google cloud platform.

 

[cobaltit]

I was referring to in 3CX itself. Settings > Security:

 

[CommsGuy]

That was it!
Thanks!
I was making it way too complicated.

 

[YiannisH_3CX]

Glad to see the issue has been resolved.