T21P E2 attended transfer caller id name in history

[JeffreyFisher]

(09-11-2019 05:20 AM)Leonard9 Wrote:  Ensure that the phone is running on the required firmware by 3CX. In case the device needs manual updating download the latest distributed required firmware by 3CX here subwaylistens. Read how to check what firmware the phones are running on and how to upgrade.

According to the Yealink Forums thread you linked to, the following config parameters need to be changed in order to show the original caller ID name in the history of a call that was transferred:

features.save_init_num_to_history.enable must be set to 1.
account.1.refresh_remote_id.enable must be set to 1.
account.1.cid_source must be set to 4.
account.1.cp_source must be set to 0.
account.1.transfer_refer_to_contact_header.enable must be set to 1.
You can find these parameters in the sip.cfg file on the Yealink T21P E2 phone.

Here are the steps on how to change these parameters:

Log in to the phone's web management interface.
Click on the "Configuration" tab.
Click on the "SIP" tab.
Scroll down to the "Account 1" section.
Find the following parameters:
features.save_init_num_to_history.enable
account.1.refresh_remote_id.enable
account.1.cid_source
account.1.cp_source
account.1.transfer_refer_to_contact_header.enable
Set each of these parameters to the value specified above.
Click on the "Save" button.
Once you have saved the changes, the original caller ID name will be shown in the history of any call that is transferred.