Yealink T21 with 3CX 12.5 RC2 CTI Mode

[VibrantJam]

Hi all,

Wondering if anyone can help me with this. Our environment the 3CX 12.5 running on VMWare with 2 network cards. 1 NIC connects to the main data network where the 3CXPhone for Windows is used and the other connects to a dedicated pair of PoE switches where the physical handsets are used. Both are in different VLANs.

Now, we historically use Polycom SIP335 phones and they're working OK from a CTI point of view. I can type a number into my 3CXPhone for Windows, press call, and the Polycom starts ringing and displaying 'MakeCall' which is what you'd expect.

Moving forward, we trialling Yealink T21 phones. For some reason (that I need your help with) CTI mode is not working. The T21's have been configured with the 'Any' setting for remote control and the 3CX Windows Client is not having any issue detecting CTI mode. I've done the firmware through the 3CX phone system and played around with the provisioning template but without success.

Any thoughts?

 

[craigreilly]

Can you do a wireshark and see where 3cx is sending the CTI command? Maybe to the wrong network...

 

[VibrantJam]

Thanks for the reply, can confirm that the the command is indeed sent and received. Have managed to fix it by factory resetting the phone, re-provisioning, sending out a new welcome email, importing the settings and then putting the phone into 3CX Mode and then back into CTI.

Very random :/