Solved This client is not compatible with the current version of 3CX Phone System

[Donovan_SouthTech]

We have recently deployed a new 3CX system for one of our clients and ran into an issue with the Windows client. The client, when attempting to register an extension on the new 3CX system will state "This client is not compatible with the current version of 3CX Phone System. 3CX Phone System Version 15 updated with the latest service packs is required". However, we are running version 15.5.5932.2 on both the newly deployed system as well as a test system in our office and the client works fine on our test system. We're also running the latest version of the Windows client.

So here's what we know so far in regards to the major differences between our production deployment and our test setup in our office:

1. We changed the USER AGENT in the 3CX Parameters on our production system because: (1) Our SIP trunk provider blocks "3CXPhone" due to toll fraud issues and (2) it's recommended by 3CX anyway to help mask your PBX's identity.
2. Our test setup in the office has the default USER AGENT (i.e. we didn't change it)
3. When we change the USER AGENT to something other than than the default on our test setup, the client fails and generates the same error as our production system. This indicates to us that there's an issue with the Windows client checking the USER AGENT on the 3CX PBX Server and failing because it thinks the client is out of date.
4. We changed the USER AGENT back on our test system, restarted the SIP services and the client would connect without issue.
5. We've verified with our SIP Trunk provider that they are indeed blocking the USER AGENT "3CXPhone" and they can't unblock it specifically for our connection, nor should they have to.

Has anyone else run into this or is there another setting that we're missing?


Thanks in advance for any insight on this issue.

 

[Marios Neophytou]

Hello,

Can you contact 3CX Support to look into your issue?

Thank You

 

[Donovan_SouthTech]

Hello,

Can you contact 3CX Support to look into your issue?

Thank You

Is there a way to contact 3CX support without it costing anything? I reached out to my reseller but they wanted $450 just to talk.

 

[YiannisH_3CX]

Hello @Donovan_SouthTech

The user agent of the PBX must not be changed nor any other change should be made through the custom parameters. This is a legacy parameter that no longer functions. I would recommend switching to a supported provider that does not block the user agent of the phone system in order to resolve your issue.

 

[Donovan_SouthTech]

Hello @Donovan_SouthTech

The user agent of the PBX must not be changed nor any other change should be made through the custom parameters. This is a legacy parameter that no longer functions. I would recommend switching to a supported provider that does not block the user agent of the phone system in order to resolve your issue.

So this, which is from a list of the system parameters, is frowned upon even though it states to change it to hide it?

"User Agent that 3CX will send can be customized. This will hide the identity of the VoIP PBX so attackers cannot know what is behind port 5060 Needs full restart of services"

Very confusing and contradictory information on this issue.

 

[YiannisH_3CX]

I understand where you are coming from but in all fairness the parameters page also states:
"This page allows editing of advanced options. Only use this after having been recommended to do so by 3CX Technical Support. ADVANCED USERS ONLY!"
When you change something in the custom parameters you do so at your own risk.

 

[Sopock]

Maybe it is possible to set custom user agent on trunk level?

 

[Donovan_SouthTech]

We wound up getting our SIP provider to make an ACL in their SBC to allow the standard 3CX user agent and it resolved everything. I still think it sucks that the user agent can be changed, is encouraged to be changed for security reasons, but then breaks certain aspects of the services.

Regardless, we're good now.