Unsupported The endpoint cannot register to the 3CX server.

[Grace Liu]

Does anybody meet with the issue like this?
When one endpoint manually registers remotely to the 3CX server, after the endpoint sends the registration request to the 3CX server, we make a capture at the 3CX server and find that the 3CX does not send any reply.


And in the 3CX log viewer, at the same time and on the same port, we see a related error message, but we can't recognize the error, can anyone help us check it?


Please check the other details here:
1. the endpoint can remotely register to 3CX server by using 3CX SBC;
2. the endpoint is not one supported ip phone model by 3CX.

Thanks
Regards
Grace

 

[Evolute IT]

"Block non-tunnel connections" in the Options tab of the user.

Also, the IP probably got blacklisted. Check your system's IP blacklist.

 

[Grace Liu]

"Block non-tunnel connections" in the Options tab of the user.

Also, the IP probably got blacklisted. Check your system's IP blacklist.

We have confirmed it:
1. The option has been disabled:
"Block non-tunnel connections"

2. The public IP of endpoint is not in the blicklist of 3CX server.

Are there any other possibilities? do you have any other suggestions?

 

[JohnS_3CX]

Hi Grace,

What is your use case here, how many connections are coming from that IP, and why are you connecting via TCP?

 

[Grace Liu]

Hi Grace,

What is your use case here, how many connections are coming from that IP, and why are you connecting via TCP?

This setup is mainly used for demonstration to different customers, because it is not convenient to carry SBC phones or 3CX SBC to the site, so the user needs to manually register the endpoint to the 3CX server remotely, and there is a problem with UDP registration, so it is changed to TCP registration. After testing, only 2 users from the public IP also get the problem, and sometimes the registration is successful, but sometimes the 3CX server does not reply after receiving the registration request.

 

[Grace Liu]

Hi Grace,

What is your use case here, how many connections are coming from that IP, and why are you connecting via TCP?

Thank you for the reminder. We checked the 3CX detailed logs again and found many connections from this public IP. May I ask what the default limit is? Can we modify this value in 3CX server?

The endpoint has been continuously initiating registration requests at roughly several second intervals, regardless of whether or not it succeeds in registering.

 

[NicholasP_3CX]

This setup is mainly used for demonstration to different customers, because it is not convenient to carry SBC phones or 3CX SBC to the site

When demonstrating to customers, you should be demonstrating the correct way to provision a phone.

If you are connecting an endpoint manually it means you are already carrying a phone, so just use a router phone in this case.

 

[JohnS_3CX]

Direct registrations (what we used to call STUN mode) are no longer supported since V20, we made that very clear.

And as a partner it's time to stop using this method entirely. We do not promote it, you should not promote it either, not even as a temporary solution.

You basically found a workaround for a problem that we have already solved for you when we took the time and effort to build the 3CX SBC. Use this as an advantage in your demonstrations.