Solved Attended Transfer treated as blind.

[Rick Sijtsma]

For a while our phones have been acting up while transferring calls.
Normally we use attended transfers, this is done by pressing the wait button, calling the other extension by BLF, then pressing XFER after talking to them.
However sometimes nothing will happen when the outside party is on Wait and the BLF is pressed.
When pressed a second time the call is transferred blindly instead.

When not pressed a second time the call will be hold in wait. When pulled out of wait and into wait again it will still not be possible to call the other extension.
Only when hard transferring, then picking the call back up with *20*, putting in wait again it is possible to make an attended call.

Does anyone have an idea why this is occuring?

• 3CX Version, Enterprise Annual 16.0.619
• Server OS, Debian 9
• Is the 3CX Server Hosted and where? OVH
• IP Phone Make/Model/Firmware Fanvil X4G with 2.10.1.6836 FW
• Provisioning Method: Local / VPN / STUN / SBC SBC
• Trunk Provider or Gateway Make/Model Custom trunk
• Has the Firewall Checker passed: YES
• Are custom Phone Templates being used: NO
• Phones are provisioned as hotdesking

 

[JohnS_3CX]

Hi Rick,

You can program the BLFs to automatically trigger an attended transfer by editing your extension, going to the provisioning tab and changing this option (reprovision your phone afterwards to receive the setting)

 

[Rick Sijtsma]

Hi John,

Thanks for the reply!
Sadly this option is already set on the hotdesking provisioning page, not able to be set on the extension itself.


To clarify: Most of the time it works as intended. 10-15% of the time the BLF does nothing while pressed, and goes to blind when pressed a second time.
Normally (even when pressed multiple times) the call will correctly transfer as attended.

 

[JohnS_3CX]

Hi Rick,

I was not aware that you were using this on a hot desking extension, but it should not really matter.

Regardless of where it's been set (normal or HD extension), we would expect that once the phone is provisioned this way then the BLFs should behave as intended. And by BLFs I mean the type should be BLF (not Speed Dial) because obviously that would not work.

I suggest:

1. provision phones for attended first
2. not using the hold button (this saves you an additional step)
3. pressing the BLF directly whenever attended transfer is needed

And for blind transfers, just hit the XFER button and then the BLF and you should be good.


Let us know how it goes when people use only this method, and if need be I can help you collect some data to analyze in case the problem does not go away.

 

[Rick Sijtsma]

Hi John,

I've checked in the phone itself after provisioning, the buttons are of type BLF/AXFER.
I'll try not using hold and see what that does. It will require some getting used to but that should be fine.

Thanks for your help, I'll keep you posted if this resolved it.

 

[JohnS_3CX]

Sure thing! I would also recommend to update your PBX to ensure that you have the latest fixes, and one last thing to mention which is important: Do not use special characters in Extension names or BLF labels.

They will not behave correctly and cause issues. I would recommend using only latin characters (ie. typical US english alphabet).

https://www.3cx.com/sip-phones/fanvil-x3-x5/#h.8owp0itk5r99

 

[Rick Sijtsma]

John,

It seems to work great when not putting the call on hold.

I've done a quick check for the Extensions/BLF labels, characters used are only a-z and space.
The PBX is to automatically update, so should always be running the latest version.

 

[JohnS_3CX]

Great news Rick, I'll mark this one as solved then, and if you have any future issues or questions feel free to start a new thread.