Yealink T28 User Manual

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Safe mode update for Yealink IP Phones
Summary: You may need to follow a safe mode update when the phone has a
problem and cannot boot properly.
Yealink UK provide a TFTP server with the latest FW versions loaded in the
correct format enabling the phone to update from this TFTP server, providing
the phone can reach this location from its current network. The public IP
address for the Yealink UK TFTP server is 178.239.102.107
Alternatively you will need to prepare a local TFTP server, put the required
firmware into the local TFTP server root and rename the firmware to the
correct format, as below. Then enable the phone to update the firmware via
the local TFTP server.
Operation Procedure using the Yealink UK TFTP Server:
1. Press and hold the Speaker button as soon as you power on the phone.
2. A prompt will display on the LCD, requesting for IP Address, Netmask, IP
Gateway and TFTP server. By pressing up/down/left/right navigation keys,
you can move among the fields using the arrow keys. (The values below
are just for reference. Depending on your network environment, you should
specify correct value for each of them) :
4. TFTP Server: 178.239.102.107 is the public IP Address of the YUK
TFTP server.
3. After completing the correct values for your network, press OK button to go
on or press cancel button to quit safe mode. By pressing the OK button, the
phone will go to download the firmware and update, during when it will
show on the LCD: (this may differ on different models)
1. IP Address: 192.168.0.222
2. Netmask: 255.255.255.0
3. IP Gateway: 192.168.0.1
4. TFTP Server: 178.239.102.107
…Updating…
Please wait…

Yealink T28 Specifications

General

Bluetooth	No
Wi-Fi	No
USB Port	No
Audio Codec	G.711, G.722, G.729, iLBC
Network Interface	Dual-port Ethernet 10/100M
Power Supply	5V/1.2A
Ethernet Ports	2 (10/100 Mbps)
HD Voice	Yes
EHS Support	Yes
Supported Protocols	SIP, RTP, RTCP, HTTP, HTTPS, DHCP, DNS, TFTP, NTP, STUN
Power Adapter	5V DC

Summary

Summary of Safe Mode Update

Yealink UK TFTP Server Update Procedure

Initiate Safe Mode

Press and hold the Speaker button immediately after powering on the phone.

Configure Network Settings

Enter IP Address, Netmask, IP Gateway, and TFTP Server details on the LCD prompt.

Start Firmware Update

Press OK to confirm settings and begin firmware download and update.

Local TFTP Server Update Procedure

Prepare Local TFTP Environment

Start a local TFTP server and place firmware files in its root directory.

Rename Firmware Files

Rename firmware files according to specific Yealink model naming conventions.

Configure Phone for Local TFTP

Initiate safe mode and input local TFTP server IP address and other network settings.

Safe Mode Update Notes and Requirements

TFTP Update Speed

TFTP is slower than HTTP/FTP, updates may take over 15-40 minutes.

Model and Firmware Compatibility

Only specific Yealink models support safe mode; requires firmware version higher than x.41.x.x.