Trunk Registration fails after restore

[VBG]

Good evening.
We have a Hosted 3CX v20.0 Update 9, PRO edition, we had some test extensions fully working. inbound/outbound calls working. We hired a local 3cx support partner to do some general configuration, setup and support. One of their support personally accidentally sync'd the whole M365 environment and sent invitation emails to everyone. To roll this back, instead of deleting the 300+ generated extensions they restored a 3CX backup, I can only assume it is the nightly backup we configured. After they restored the backup our system will no longer register with our carrier. I've gone back and forth with the carrier and they say we are not sending any registration requests since the PBX restore. PCAP shows up sending, but no return traffic from the carrier. However in our 3CX event log I see this;

Event ID 12293
Registration at <name> SIP Provider has failed. Destination (sip:x.x.x.x:5060;lr) is not reachable, DNS error resolving FQDN, or service is not available.

In the PCAP I see 408 Request Timeout.

When I disable Registration in the trunk settings the trunk shows up, but of course calls are rejected because registration is required.

Our phones are registering to 3CX, any diagnostics I run seem to be good. I don't have shell access to the hosted environment to run nslookup to make sure DNS is resolving, but from what I can tell the DNS servers are 8.8.8.8

SIP registration username and password verified, carrier even changed the PW and gave us a new one.

 

[SteveITS]

Is the carrier IP blacklisted?

 

[VBG]

Do you mean under Admin > Advanced > IP Blacklist?
I have added all my public IP's and the carrier's IP that shows up in the log file.

 

[VBG]

I also just tried an offline free version of 3cx installed on a local VM in my home lab, I put the credentials and I am seeing the same messages. This kind of points me to it being a credential issue with the carrier? Thoughts?
I have reported this to the carrier support, but they did not seem convinced it was a them issue.

 

[KyriacosS_3CX]

On the PBX, does the firewall checker pass and if you go to the Trunk config page and do Check SIP Trunk, what comes up?

 

[Kevin Attard Compagno]

If you are unable to register from 2 different PBXs, which live inside a different network paradigm, AND both PBXs pass the firewall checker, THEN it is logical to look at the issue from the carrier's perspective - since the carrier is the common element.

As an aside, note that an IP-based trunk will always show "green", because there is no registration process and/or credentials to confirm or otherwise whether successful exchanges are possible.

 

[VBG]

understood, we have pushed it back to the carrier, with PCAPs, and multiple Call-IDs found in the PCAP.
I am just trying to wrap my head around what happened, or broke when the system restore was done.

 

[VBG]

On the PBX, does the firewall checker pass and if you go to the Trunk config page and do Check SIP Trunk, what comes up?

This is hosted on 3CX, but the firewall says: Firewall test OK: SUCCESS