Solved 3CX Phone System 01 SIP Server causing high CPU usage

[elliotstewart]

Hi all,

In a bit of a bind with one of my clients.

The System all of a sudden started sitting at 100% CPU usage. After restarts of the box and even restores to backups the CPU usage is sitting around 70-100%. After checking Services 3CX Phone System 01 SIP Server seems to be the cause. Stopping this service the box immediately flies down to 1-3% CPU usage.

We have had issues with phones not registering, calls dropping or having audio issues and the Portal not updating event logs for hours all im thinking are related to the CPU usage.

The 3CX box is on a Azure hosted virtual machine
OS: Linux (debian 9.9)
3CX Version: 16.0.493 (Was the same issue before upgrading to this version today)

Help would be greatly appreciated!

 

[elliotstewart]

Happy for this to be removed. I have just rebuilt the box from scratch and looks to be working without issue now.

 

[JohnS_3CX]

Hi @elliotstewart

Great news, let us know if it comes back

 

[elliotstewart]

It did end up coming back and I had the same issue after the rebuild.

After some more troubleshooting with the client we worked it out to be the clients side firewall with a hidden SIP NAT setting that they were unable to find was preventing some phones from registering and others from functioning correctly. The phones seemed to be flooding the 3CX box with RPS requests I believe causing all the issues but logs were not being created due to the box running at capacity.

Turning off the SIP NAT rule instantly fixed the issue and the CPU is now sitting at a cool 1-3%, phones are provisioning and call queues and ring groups are all functioning correctly.

It's always SIP ALG...even when the client says it's not on their router haha.

 

[JohnS_3CX]

Glad to hear it was resolved!