Yealink T28p no longer working after CudaTel firmware update

[AshElsayid]

I have about 35 Yealink T28p phones that were all working fine using the 2.60.0.153 firmware. I, over the weekend, upgraded our CudaTel VoIP firmware to version 3.0.004.016. After this update was completed, the Yealink phones updated themselves to firmware version 2.72.0.26. This morning i have found that none of the phone are working at all. All phones show "obtaining IP address". I have tried factory reset to the phone, and still no provisioning is happening. One one extension, I entered all the network setting manually, and after a restart and provision, the user get his extension to show on the phone, but when calling the extension, it goes right to voicemail.

Any help would be greatful as Yealink is based in China and has no US offices.

[James_Yealink]

Hi,

In V60 frimware the LLDP feature is disabled as default but in new firmware it's enabled. The "obtaining IP address" issue may be cause by this change.

Have you configured a vlan setting in your network? If yes, please set a correct lldp-med VID in your switch. If not, you may have to disable the LLDP in phone or switch.The LLDP feature has to be disabled in web interface in V72.

About the second issue, can you try manually registering the account and check again? I think no forward option set in phone?
A pcap trace is needed to analyze the issue. Go to setting-> configuration, enable the pcap trace, make a call, then stop the pcap trace, export it. This issue seems more like a server issue. Need to confirm through pcap trace.

Regards,
James