Solved 480 Temporarily Unavailable

[jcolton3]

Both incoming and outgoing calls are failing. We recently moved our 3CX install from Amazon Lightsail to Azure. Everything appeard to be fine for a few days, then calls stopped going through. Our Telnyx SIP trunk is registering fine, but incoming calls are not going through. The Telnyx logs indicate that the SiP INVITE are being sent but not acknowledged. (Note that I can't find any corresponding entries in any of the logs on the 3CX.) I suspect this is a firewall related issue or possibly an IPv6 issue, but am at a loss on how to resolve the issue.

• The issue was originally occuring on V16. I succesfully upgraded to V18 but the issue persists.
• Deleting and recreating the Telnxy SIP trunk did not resolve the issue either.
• This 3CX instance passed all firewall checks.

Any help would be greatly appreciated.

Here are the details on this 3CX instance:

• 3CX Version: 18.0 (Build 1880)
• Server OS: Debian 10
• 3CX Hosted at Azure but was originally hosted by Amazon Lightsail created a couple of years ago using the pbxexpress.
• IP Phone Make/Model/Firmware: Snom D717/D785, latest firmware
• Trunk: Telnyx
• Firewall check passed
• Custom phone templates are in use, but issue does not appear to be related.

Thank you!

 

[jcolton3]

I believe I may have stumbled upon a fix for the issue. After reviewing the following post by @Chris Ruffin

Telnyx TLS trunk connection with V18
https://www.3cx.com/community/threads/telnyx-tls-trunk-connection-with-v18.84526/#post-395778

and thinking about @Frederick Marcoux 's suggestion to make sure the root certificate was uploaded, I decided to remove and re-add the Telnyx SIP trunk following the instructions contained in the following configuration guide:

Telnyx VoIP Provider
https://www.3cx.com/docs/telnyx-voip-provider/#h.7ovuyic3movz

After configuring this new SIP trunk to use TLS and configuring the corresponding Telnyx connecion to use SRTP, I was able to make and receive external calls!

So I suspect somewhere along the way, either 3CX or Telnyx, or both, likely made some change requring more secure connections.

Hope this helps anyone else running into this same issue.

 

[YiannisH_3CX]

Telnyx trunks can work either with UDP or TLS you just need to make sure that both sides are configured for the same transport.
Glad to see you were able to find a solution to your issue. Please do not hesitate to create a new thread if you face any more issues.