Session border controller disconnects regularly after a couple of weeks of stability

[Matt Holder]

Hi,

In the last six weeks or so we have an issue at one of our sites where phone calls are being dropped. A reboot of the main server solves the issue, but there must be something going on that I'm struggling to troubleshoot. Things are stable for around two weeks and then we see the issue.

We have our main phone server at site A (running update 3). Site B runs an SBC (latest version) and supports nearly forty phones. I also have a test SBC at site C and this supports a couple of phones.

When the issue occurs site B keeps dropping calls and I can see that the SBC keeps going up and down in the SIP trunks panel on 3CX.

When we see the issue site C does the same thing.

I think I've ruled out the firewall at the three sites as the issue goes away on a reboot of the server at site A.

Help will be gratefully received

 

[eddv123]

What version of 3CX and SBC are you using? Have you performed any troubleshooting (SBC logs for example).

Windows or Linux ?

I have not experienced myself but have had a few stability concerns reported to me in regards to the v16 SBC (compared to v15.5) however commonly the issues are either.

* DNS failure: local network issue, this can be clearly seen in the logs also, if DNS fails the tunnel connection will drop.

* TCP port closes: again network issue due to the firewall (or in a couple of cases double NAT/multiple firewalls) close the tunnel port and close the connection

Switching to TLS can help. You may also want to confirm if using Windows if the updates,antivirus and firewall are turned off as well.

 

[Matt Holder]

Thanks for the ideas. I'll have a look once I'm back at work. I did switch off TLS at one point as I thought that was the issue, so maybe I'll try switching it back on again after checking the other items.

I'm running v16 update 3 and the latest SBC that came out with/after v16

 

[eddv123]

If the issue is easily/frequently replicable then I would stick the SBC logging into Verbose and log the disconnected error.

Note: When you change the setting you must "push" the configuration down to the SBC in order for it to take effect.

 

[Matt Holder]

Thanks a lot for this. I'll take a look when back off leave. It's weird that this has started to happen as it's been rock solid for months prior.

 

[eddv123]

See what the errors are but my advice would be to perhaps check the local firewall/network for any changes made recently (If this problem has only just occurred).

 

[ivank]

Hi Matt!

The fact that reboot of the PBX server solves the problem suggests that the root cause is there.
When it happens next time, logon there and try to observe and collect as much info as you can before rebooting. For example:

• How much CPU is consumed and by what process (es)?
• How much memory is free? Which processes consume it most?
• Collect 3CXTunnel logs.
• Check OS event logs.

Some scheduled tasks which bring the server down, perhaps?

 

[hogan71088]

I have started having this problem on a recent install. Looks like the instance was set to auto update to 16SP4. One SBC is fine but the other is dropping out.