3CX and T46U as router phone

pyrobert69

SMB User
Joined
Feb 16, 2025
Messages
9
Reaction score
2
Hi all

I have recently setup a 3CX FREE 10 Users account with two extensions.

Our main phone (first extension) is a Yealink T46U which according to the 3CX documentation can be setup as the router phone (SBC). It is on firmware version: 108.86.119.2.

Our second phone (second extension) is also a Yealink T46U on the same firmware version.

In the 3CX Admin Console I setup both extensions to be auto provisioned using the provisioning link. I have then dropped that link onto the phones using the Yealink web UI.

When the T46U's boot up and attempt to register, they both fail resulting in the blocking of my public IP address for 24 hours. I have also attempted to configure them manually as well, with the same result.

Strangely I can register the two extensions on mobile phones (by scanning the QR codes). They work perfectly on a mobile connection (in my case EE in the UK).

Digging into the settings on the Yealink phones themselves, the hostname and port are all correct, as are the usernames and passwords etc.

Does anybody have any suggestions as to why the extensions register fine on mobile phones (connecting to https://****.3cx.cloud/) but not on the Yealink T46U's when on my broadband connection. Does the T46U acting as the SBC need to have NAT setup on the firewall? Should SIP ALG be enabled or disabled?

I was meant to have the system up and running by tomorrow morning so any assistance would be greatly appreciated.

Many thanks,
Graeme
 
Last edited:
As per our guides, the firmware will need to be updated to enable the router function prior to the configuration.

I'm confirming that 108.86.119.2 is not a supported version (the 119 part indicates the current firmware is likely custom).

You need to install this version here and then factory reset it
https://www.3cx.com/docs/phone-firmwares/

If you have trouble, please contact your seller or Yealink directly, we cannot help you any further in the firmware installation.
 
  • Like
Reactions: GregG_3CX
Thank you. I would never have known that 108.86.119.2 is a custom firmware version. The T46U would not let me change to 108.86.0.93, so had to roll back to 108.86.0.70, then upgrade to 108.86.0.90 and then finally up to 108.86.0.93. Will try re-register/auto-provision later today once my IP has been unblocked.
Many thanks.
 
  • Like
Reactions: JohnS_3CX
@JohnS_3CX is there any way to unblock my IP manually? Each time I am blocked I have to wait 24 hours, which is putting me behind schedule. I was meant to demo today which I am not able to do now unless I can register the phone.
 
@JohnS_3CX is there any way to unblock my IP manually? Each time I am blocked I have to wait 24 hours, which is putting me behind schedule. I was meant to demo today which I am not able to do now unless I can register the phone.
Only the support can unblock you. That will cost you some money.
 
Only the support can unblock you. That will cost you some money.
Doesn't make it easy for them to upsell does it? You should be able to unblock your own IP at least.
 
Doesn't make it easy for them to upsell does it? You should be able to unblock your own IP at least.
Its the Free pbx, you cant upsell this one. Thats why support isnt free.
 

Members Online Now

No members online now.

Forum statistics

Threads
111,831
Messages
589,277
Members
164,660
Latest member
RJenkinsROCK