Can't upgrade the phone from 3CX, choose, upgrade firmware, check Yealink T28 2.70.0.168, click upgrade,
, click finish, phone reboots and stays on 2.70.0.140.
Updating model Yealink T28
Downloading 2.70.0.168.rom
Local file is up to date (delete it manually if you want to re-download it)
Applying new firmware for the phone of extension 130
Sending SIP notify to the device with MAC=00asdfEE
Click Finish. Your phone will reboot automatically and upgrade the firmware.
So i did a manual upgrade to 2.70.0.168 from the webinterface, and have captured an error below with wireshark.
From Wireshark when trying to dial a number via CTI.
Source:deskphone, Destination

C
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><HTML> <HEAD> <TITLE>Yealink</TITLE> <META http-equiv=Content-Type content="text/html; charset=utf-8"> <META http-equiv=Pragma content=no-cache> </HEAD> <BODY> <TABLE cellSpacing=0 cellPadding=0 width="100%" border=0> <TBODY> <TR> <TD vAlign="top"> <FORM method="post"> <TR><TD></TD><TD class="normalText"><B>
You are not authorized to access the web interface.</B></TD></TR> <TR><TD></TD><TD><SPAN class=pageInfoText><br><br> Please contact your support team or try again 3 minutes later. <br><br><hr><br><br>HTTP 401<br><br> </SPAN></TD></TR> </FORM> </TD> </TR> </TBODY> </TABLE> </BODY></HTML>