BLF not working with error 489

[paco3346]

I'm trying to set up BLF on a third party device (Unifi UVP Touch) and when I configure the phone I see (via wirehsark) the SUBSCRIBE packet go out.

The SUBSCRIBE request has Allow-Events: presence, message-summary, refer
The response from 3CX is 489 Event package not supported

2 questions with this:
Is this error message referring to that header including types of events 3CX doesn't support? If not, what does it refer to?
If yes, what events does 3CX support / expect?

 

[YiannisH_3CX]

Hello @paco3346

Please note that since this device is not supported it has never been tested by 3CX so we are not aware of its behaviour. From the provided information though it looks like that the phone is using the "Allow-Events" when it should be using the "Allow" header which is what the PBX is using.

 

[paco3346]

Excellent, this is exactly the kind of information I'm looking for. Thanks so much!!

 

[paco3346]

Also, just for my own understanding, what Events does 3CX support?

 

[paco3346]

Per rfc3265 there is an 'Event' header and an 'Allow-Events' header. Now that I understand the difference I re-ran a packet capture and found that my subscribe event has 'presence' in the Event header.

In the 489 response that I receive from 3CX it has "presence, message-summary, dialog, call-info, line-seize" in the Allow-Events header. Perhaps there's something else 3CX is looking for in the subscribe request?

 

[YiannisH_3CX]

3CX does not support presence for IP phones. Presence is for 3CX clients and it is distributed via a difference service not via SIP. For IP phones that subscribe for BLF keys on the PBX any changes are communicated via a NOTIFY message that needs to be supported by the end point.

 

[paco3346]

Got it. Thanks for confirming!

Why does the response include presence in the Allow-Events header then?