We are having a problem with BLF lights freezing when using Yealink’s 83.0.X firmware. We caught it acting up and sent Yealink a bug report. Their response is that the BLF’s need to use a different RFC standard.
Dear Customer,
This is East from Yealink Technical Support team, nice to meet you.
Thank you for the detailed information.
After I checked the syslog that you provided, I can confirm the reason. Please see the detail bellow:
When the monitored status change, the server will send NOTIFY to the phone, there is a BLF version on the NOTIFY.
In our V81 version, the phone will not check the BLF version in the NOTIFY. But in the V83 (actually updated in V82), the phone will check the BLF version.
We modified it because it is compliant with standard RFC4235, it is a better update. Please see description of BLF version below:
Version: This attribute allows the recipient of dialog information documents to properly order them. Versions start at 0, and increment by one for each new document sent to a subscriber . Versions are scoped within a subscription. Versions MUST be representable using a non-negative 32 bit integer.
But according to the syslog, after received NOTIFY from server, the phone found that the version is smaller than the previous one, it is a substandard parameter. So the phone will not update the status of the BLF, and prompt error like: BLF bad version param. Cur ver=71, new ver=26
As our phones refer to the standard RFC4235, please contact your service provider to modify the NOTIFY message, and let it also refer to the standard. Then it will work well in BLF.
Where can I set the blf’s to use RFC4235 as they suggest?
Freepbx 14 asterisk 13.22
Asterisk Forum post: BLF’s not working right with Yealink 83.0.X firmware. Response from Yealink - Asterisk SIP - Asterisk Community