3CX PhoneSystem01 service stops running

[zaycium.lemmert@idmgroup.]

We recently upgraded from V18 on Windows to V20 on Linux Debian 12 using the ISO provided on the 3CX website. All recommendations and guidelines were followed during the upgrade. However, within two days we began experiencing multiple instances where the SIP service would randomly stop and require a manual restart. Upon reviewing the logs, it became clear that the actual issue lies with the PhoneSystem01 service failing. There are no signs of resource constraints or buildup, the service simply drops unexpectedly. Could the possibility of a memory leak be the route cause.

3CX INSTANCE:
Version 20.0 Update 6 (Build 724 Release)
512 PROFESSIONAL
Self hosted



As a mitigation measure, we increased the swap memory.

total used free shared buff/cache available
Mem: 31Gi 4.6Gi 256Mi 437Mi 27Gi 26Gi
Swap: 15Gi 655Mi 15Gi

We expanded the C: drive disk size from 200GB to 400GB.

Done a config cleanup.

However, we are still experiencing service drops, occurring almost every other day.

Could you please direct me.

 

[KyriacosS_3CX]

Hello,

This should be investigated via a support ticket, which you can open via the customer portal, or ask your PArtner to open for you.

 

[zaycium.lemmert@idmgroup.]

This matter was escalated to our Partner, who logged the ticket with your support over 3 weeks ago. Since then, the only update received has been that the issue is under review by 3CX Level 3 support.

@KyriacosS_3CX, I need to emphasize the critical impact this is having on our business. Our telephony infrastructure is the backbone of our operations, and the ongoing issue is resulting in the loss of both potential and existing clients.

At present, there appears to be no resolution in sight.

 

[KyriacosS_3CX]

Hello,

I have checked with the support team and I will provide further details in Direct Message.

Thanks,
KS.

 

[KTG-EDUCATION]

Hello,

We're seeing a memory leak condition that seems to have started around Oct of this year on a few of our installations. All running Windows 11, 3CX Version 20.0 Update 7 (Build 1080 Release), and on new Dell hardware all installed within about 12 - 16 months ago. Symptoms are that 3CX will alert that DB, gateway and other services have stopped and system needs to be hard restarted. This occurs again 1 - 3 days later. Small/Med installations for schools with about 30 exts. We're investigating all options but curious if any others are seeing this out there. Again, these systems ran fine with never an issue up until about 30 - 45 days ago.

 

[SweetAction]

Hello,

We're seeing a memory leak condition that seems to have started around Oct of this year on a few of our installations. All running Windows 11, 3CX Version 20.0 Update 7 (Build 1080 Release), and on new Dell hardware all installed within about 12 - 16 months ago. Symptoms are that 3CX will alert that DB, gateway and other services have stopped and system needs to be hard restarted. This occurs again 1 - 3 days later. Small/Med installations for schools with about 30 exts. We're investigating all options but curious if any others are seeing this out there. Again, these systems ran fine with never an issue up until about 30 - 45 days ago.

I would start a new thread since this is a few months old and about Debian and not Windows.

 

[KTG-EDUCATION]

Understood, thanks. Working thoughts are this is all Windows software related and not 3CX or hardware.

 

[SweetAction]

Understood, thanks. Working thoughts are this is all Windows software related and not 3CX or hardware.

Event logs should say why the service was commanded to stop.

 

[KTG-EDUCATION]

Exactly. Windows is not the OS it was 25 years ago We've isolated things we think to Windows trying automatically to be a cache server like Mac introduced years ago, and in doing so killing App memory. We're learning here too and adjusting as need as we love 3CX.

I posted to see if others had this experience w/ 3CX uniquely and given no posts and our OS logs we feel good about the diagnosis.

Thanks for the resp.

 

[zaycium.lemmert@idmgroup.]

Good day Ilias,

Hope you are doing good.

I need some assistance with a very weird issue happening intermittently.

We are currently experiencing an ongoing issue involving no audio when Financial Advisors (FAs) using Genesys conference to Financial Consultants (FCs) on 3CX. All other inbound and outbound calls from 3cx are working 100%. Are there any logs that identify the issue.

Example scenario:

1. A Genesys FA initiates a call with a client.
2. An FC using 3CX joins the call via conference.
3. The FA and FC are unable to hear each other, and including the client is also unable to hear one or both parties.

We would appreciate your assistance in attempting to isolate the issue.

 

[bitn2]

Good day Ilias,

Hope you are doing good.

I need some assistance with a very weird issue happening intermittently.

We are currently experiencing an ongoing issue involving no audio when Financial Advisors (FAs) using Genesys conference to Financial Consultants (FCs) on 3CX. All other inbound and outbound calls from 3cx are working 100%. Are there any logs that identify the issue.

Example scenario:

1. A Genesys FA initiates a call with a client.
2. An FC using 3CX joins the call via conference.
3. The FA and FC are unable to hear each other, and including the client is also unable to hear one or both parties.

We would appreciate your assistance in attempting to isolate the issue.

Open your own thread with your problem and all infos we need. Thats not helpfull to post in an old thread to a different problem

 

[KyriacosS_3CX]

We are having the exact same issue.

Error 30035 02/14/2026 1:41 PM 3CX Event Notification Manager
The following service(s) were interrupted:. 3CXSystemService01

We have to restart it multiple times a day; it seems like it started since the last patch update.

We have over 300 extensions and 5 locations; and it is impacting business, phone calls, transfers, voicemail delivery.

We are using the linux\debian install in the cloud with SBC's connected.

Any solution coming down the pipe?

Hello,

It is not possible to say whether the issue or solution is the same as in the original post - you can start a new thread so we can try and see here what the way forward is, or open a ticket with support that can investigate to much greater detail in such matters.