SBC Trunk going down at roughly the same time every couple of hours

[Ocean Support]

Hi there,

We've been having an issue with our PBX on a customer's site.
They have been getting Error 4102, "Trunk SBC '*Phone Model* *Ext*' (*Public IP*/*Device IP*) has changed status to Down"
When this happens, the calls drop and the customer is getting pretty irate about this.

The timing on this has been mostly consistant.
From yesterday, the timings were:

25/03/2025 23:01
25/03/2025 21:00
25/03/2025 18:59
25/03/2025 17:58
25/03/2025 15:57
25/03/2025 13:57

I have provisioned a phone on their PBX and plugged it in at our office, and when all the extentions drop, this one stays connected.
Some of the phones are on a seperate data connection at their office but still dropping with all the others.

Does anyone have any ideas on what we can do about this?

Some information:

• 3CX Version: V20, Enterprise
• Server OS, Rocky Linux 8.4
• ISO Used: 3CX Debian ISO
• Is the 3CX Server Hosted and where? Self-Hosted - Cloud Based
• IP Phone Make/Model/Firmware version, Fanvil V62 2.12.18.8, Yealink T46U 108.86.0.77
• Provisioning Method: SBC
• Trunk Provider or VoIP Gateway Make/Model, Giacom
• Has the Firewall Checker passed: Yes
• Are custom Phone Templates being used: No

 

[Alphabetic]

I would either check the phone has a static IP or is reserved in the DHCP server.

The DHCP server lease time could be an hour or it could be an IP conflict.

or a faulty network cable.. port.. etc.

do a continuous ping to the IP of the SBC and to the router.

 

[Alphabetic]

Also, it seems very suspicious that something is happening on the hour...

 

[Peter Tomlins]

Can I ask if this is hosted on OVH? We witnessed this behaviour with OVH for a single customer a few months ago - ended up moving them to Digital Ocean as OVH took forever to fix it (we'd given up and pre-emptively moved it by then).

Curiously, other customers on OVH were unaffected.

 

[Alphabetic]

Can I ask if this is hosted on OVH? We witnessed this behaviour with OVH for a single customer a few months ago - ended up moving them to Digital Ocean as OVH took forever to fix it (we'd given up and pre-emptively moved it by then).

Curiously, other customers on OVH were unaffected.

Had issue similar. Check the automated backups.