Calls not connecting

[AndreHTP]

We've recently setup a client with their own privately hosted Linux based 3CX server hosted on ESXi 6.7.0 Update 1. They are still in the testing phase and every couple of weeks they are unable to connect when making outbound calls. It rings for them but doesn't connect at the SIP provider. Activity and Events logs don't show any errors and a packet capture seems to show communication with the SIP provider's server. The SIP provider says that they see no traffic coming from the client's server. The only way to get things working again is by restarting the VM itself, simply restarting services via the 3CX console doesn't resolve the issue.

Has anyone seen anything like this before or have any idea where else to look?

 

[Evolute IT]

We've recently setup a client with their own privately hosted Linux based 3CX server hosted on ESXi 6.7.0 Update 1. They are still in the testing phase and every couple of weeks they are unable to connect when making outbound calls. It rings for them but doesn't connect at the SIP provider. Activity and Events logs don't show any errors and a packet capture seems to show communication with the SIP provider's server. The SIP provider says that they see no traffic coming from the client's server. The only way to get things working again is by restarting the VM itself, simply restarting services via the 3CX console doesn't resolve the issue.

Has anyone seen anything like this before or have any idea where else to look?

Does the firewall checker pass?

Does the VM have a "bridged" network connection to the LAN?

What provider is it and how is it configured? (IP-based or register-based)

 

[noord]

You need to figure out where the issue lies.

If I were you, I'd grab some simple computer, install Linux on it, backup 3CX and restore on that 'new' computer.
If it then keeps running correctly, you know something is wrong with ESX / the computer that's running ESX or whatever.
If it has the same error, you know the problem perhaps lies within some firewall in your network.

I did see similar issues, where a router would stop handling all traffic from a certain IP. After rebooting the computer, it would get a different IP address and that's why the problem resolved after rebooting. But that's probably not your issue, but it does happen.

Considering all things you've said, it would suspect an issue with the ESX-host in your case.

 

[JohnS_3CX]

a packet capture seems to show communication with the SIP provider's server

If you provider is not seeing your traffic, the question becomes who is replying back to the PBX then in the capture?

Find out what the IPs are and you will learn why this is happening.

 

[noord]

If you provider is not seeing your traffic, the question becomes who is replying back to the PBX then in the capture?

Find out what the IPs are and you will learn why this is happening.

I didn't quite read that the way you have -- if this is really the case, then this is very interesting

But it's still very strange then that a reboot of the VM would solve it (and a restart of services won't).
I'm really curious the hear what the cause turns out to be.

 

[AndreHTP]

Does the firewall checker pass?

Does the VM have a "bridged" network connection to the LAN?

What provider is it and how is it configured? (IP-based or register-based)

The firewall checker does pass, both when the issue is active and when the server is rebooted.

It has a single virtual network adapter provided by the ESXi host which is on the LAN that the firewall is on.

The provider is Magnet. I know they aren't a "supported" provider but the client has been using them since before the 3CX server install.