Yealink SIP-T4X Administration Manual page 231

Administrator's Guide for SIP-T4X IP Phones
A dialog box pops up to prompt "Firmware of the SIP Phone will be updated. It will
take 5 minutes to complete. Please don't power off!".
5. Click OK to confirm the upgrade.
Note
Do not unplug the network and power cables when the IP phone is upgrading firmware.
Do not close and refresh the browser when the IP phone is upgrading firmware via web
user interface.
Upgrade Firmware from the Provisioning Server
IP phones support to use the FTP , TFTP , HTTP , and HTTPS protocols to download the
configuration files and firmware from the provisioning server, and then upgrade
firmware automatically.
IP phones can download firmware stored on the provisioning server in one of two ways:
Check for both configuration files and firmware stored on the provisioning server

during booting up.
Automatically check for configuration files and firmware at a fixed interval or

specific time.
Method of checking for configuration files and firmware is configurable.
Procedure
Configuration changes can be performed using the configuration files or locally.
Configuration File
216
<y0000000000xx>.cfg
Configure the way for the IP
phone to check for
configuration files.
Specify the access URL of the
firmware.