OVH SIP trunk no longer registers on 3CX Hosted since 15 June 2026 - forced unregister

[acti67]

Hello,

I have a 3CX Hosted instance with an OVH France SIP trunk which stopped registering around 15 June 2026.

OVH indicates the SIP server as: sbc6.fr.sip.ovh:5060

There is no IP restriction on the OVH side.
The SIP password has been reset and updated in 3CX, but the trunk still does not register.
OVH does not show any registration/authentication error in their notifications.

3CX shows:

The SIP Registration attempt got a failure response [forced unregister]

In the 3CX provider report XML, I noticed the OVH provider template contains readonly values pointing to different OVH servers:

<field name="RegistrarHost" status="readonly">siptrunk.ovh.net</field>
<field name="RegistrarPort" status="readonly">5060</field>
<field name="ProxyHost" status="readonly">e164.sip.ovh</field>
<field name="ProxyPort" status="readonly">0</field>

But the report also shows the trunk resolving/testing:

sbc6.fr.sip.ovh -> 91.121.129.134:5060 UDP

Questions:
- Is the current 3CX OVH France provider template still valid for OVH trunks using sbc6.fr.sip.ovh:5060?
- Can the readonly siptrunk.ovh.net / e164.sip.ovh values cause incorrect SIP registration headers or routing?
- Has anyone else seen OVH trunks fail with [forced unregister] on 3CX Hosted since mid-June 2026?

I can provide the provider report XML if needed, with sensitive data removed.

Thanks,

Stéphane

 

[fred252]

I have exactly the same issue since June 26th after more than one year of good service.
Nothing changed on both sides ... upgrade to v20 maybe ?
3CX SMB fails to register with the same message: "The SIP Registration attempt got a failure response [forced unregister]"

Were you able to solve this issue somehow ?

 

[Fadas17]

Hello,


I have the exact same issue on a 3CX Hosted / Free instance with an OVH France SIP trunk.


The OVH SIP account registers successfully with Zoiper, so the SIP credentials seem to be valid.


However, in 3CX Hosted, the trunk stays unregistered and the SIP Trunk Checker shows:


forced unregister


I also saw this in the 3CX Event Log:


500 Registering glare condition


My OVH SIP settings are the standard OVH France ones:

• Registrar / proxy: sbc6.fr.sip.ovh
• Port: 5060
• Transport: UDP
• SIP login and authorization username match the values provided by OVH

Tests already done:

• Reset the OVH SIP password and updated it in 3CX
• Tested with OVH IP restriction enabled for the 3CX public IP
• Tested with OVH IP restriction disabled
• Recreated the trunk using the OVH provider template
• Recreated the trunk using Generic VoIP Provider (Registration)
• Tested with the main trunk number in both +33... and 0033... formats
• Forced transport to UDP
• Made sure Zoiper was disconnected during 3CX tests
• Made sure only one 3CX trunk was using this SIP account

The result is still the same: Zoiper registers, but 3CX Hosted fails with forced unregister.


This looks very similar to your case and may be related to the OVH provider template or to a change on 3CX Hosted around mid-June.


I can provide screenshots of the SIP Trunk Checker and Event Log with sensitive information removed if needed.

 

[KyriacosS_3CX]

Hello,

Have you raised the issue with OVH?

 

[Fadas17]

Hello,


Yes, I have raised a ticket with OVH.


OVH confirmed that they do not see any issue on their side. They also confirmed that the SIP account is valid.


I tested the same OVH SIP account with Zoiper, using the same registrar, SIP login and password, and it registers successfully.


So the Zoiper test confirms that the OVH SIP credentials and the OVH SIP service are working.


The issue only happens with 3CX Hosted / Free. In 3CX, the trunk stays unregistered and the SIP Trunk Checker still returns:


forced unregister


I also saw this in the 3CX Event Log:


500 Registering glare condition


This is why I suspect the issue may be related to 3CX Hosted, the OVH provider template, or a change in the 3CX Hosted environment.


Could you please advise what else can be checked from the 3CX side?

 

[fred252]

OVH reported no malfunction. I did not found any "failed registration" log on their side.
I disabled IP restriction, updated the password to no avail.
I was able to connect with Zoiper and Linphone gracefully.

My last log line in 3CX is:

Info,4100,2026-06-26 08:06:18Z,Trunk L:13200(*****) has changed status to unregistered

Attached a screenshot of the SIP Check.